VI. SIR-C/X-SAR SCIENCE TEAM and INVESTIGATIONS
Institute for Meereskunde H. Masuko Radio Research Laboratory Troplowitzstr. 7 Paolo Trivero Istituto di Cosmogeofisica
D-22529, Hamburg
GERMANY
Comparison of SIR-C Simulated and Measured SIR-C SAR Image Spectra with Ocean Wave Spectra Derived from Buoys and Wave Production Models in the North Sea
I. OBJECTIVES
a) Carry out measurements of two-dimensional ocean wave spectra by a pitch and roll buoy from the Forschungsplatform Nordsee (German Research Platform North Sea) and from a ship of the German Hydrographic Office in the North Sea. Collaborate with of North Sea oil rig operators to obtain wave spectra from these sites.
b) A third generation wave prediction model (WAMODEL) will be applied to forecast, respectively hindcast, the wavefields in the North Sea from the measured wind history during the SIR-C overflight. The WAMODEL has a resolution of 0.5 degrees longitude and 0.25 degrees latitude. This model (Komen and Zambreski, 1986; Bauer et al., 1988) seems to be accurate in predicting two-dimensional ocean wave spectra in the North Sea and will be refined for the SIR-C mission.
II. APPROACH
a) Compare two-dimensional wave spectra measured by buoys and calculated from the wave prediction model (WAMODEL) over the entire North Sea (and Atlantic) with the X-, C-, and L-Band SAR image intensity spectra of SIR-C.
b) Apply SAR imaging theory (Alpers and Rufenach, 1979, Alpers et al., 1981; Alpers, 1983; Alpers and Bruning, 1988; Alpers et al., 1986; Bruning et al., 1988a, 1988b) to the measured and predicted ocean wave spectra to predict the X-, C-, and L-Band SAR image spectra of SIR-C.
III. ANTICIPATED RESULTS
a) Determine the accuracy of the SAR wave imaging theory to both measured and predicted ocean wave spectra in the North Sea.
b) Determination of the optimum hydrologic and meterologic conditions for routine mapping of sea bottom topography using SAR data.
c) Determination of the optimum radar parameters for routine mapping of sea bottom topography.
The Johns Hopkins University Thomas W. Gerling Applied Physics Laboratory
Applied Physics Laboratory Frank M. Monaldo Applied Physics Laboratory
Johns Hopkins Road
Laurel, MD 20707-6099
Wave Dynamics in the Southern Ocean
I. OBJECTIVES
a) Construct a spatially continuous daily estimate of the directional wave energy transport across the only pure ocean circumpolar route on the planet, a route that is just to the south of the net source function (i.e., south of the maximum wind zone).
b) Determine the temporal and spatial variability of the directional wave transport in the study area over the mission.
II. APPROACH
a) Collect a total of 96 three-minute data-takes with C-band HH polarization, south-looking at 25deg. incidence angle. This geometry will permit the acquisition of a contiguous sequence of six complete circumpolar data sets at 58deg.S, nearly centered on the narrow Drake passage.
III. ANTICIPATED RESULTS
From this data set, and by extending our L-band algorithms developed and verified with SIR-B, we will:
a) Estimate the angular distribution of total wave energy flux through the 58deg.S latitude circle and partition the total energy into sixteen 22.5deg. longitude zones;
b) Determine the temporal and spatial variability of the directional wave energy transport in each of the 22.5deg. zones over the total mission duration; and
c) Calculate the angular distribution of total wave energy transport versus longitude by normalizing the (relative) spectra with the mean monthly wave height determined from Geosat altimeter averages, which are essentially invariant from year to year (based on 1985 to 1987 data).
Applications Technology Div. H. Gwyn University of Sherbrook
Centre for Remote Sensing T. Pultz Canada Ctr. for Remote Sensing
4th Floor, 1547 Meridian Rd K.P.B. Thomson Laval University
Ottawa, Ontario K1A 0Y7
CANADA
Multi-Incidence Angle/Multi-Frequency Effect in Satellite SAR Imagery Pertaining to Vegetation Characterization and Hydrology
I. OBJECTIVES
a) Evaluate the range of incidence angles over which radar backscatter is predominately from the underlying soil, the vegetation canopy, and a combination of the two as a function of frequency and polarization; develop models to characterize the backscatter.
b) Evaluate the synergism of VIR and SIR-C/X-SAR data for crop type discrimination and as an input to remote sensing/meteorological crop yield models.
c) Evaluate SIR-C/X-SAR data for soil moisture and as an input to watershed run-off prediction models.
II. APPROACH
a) Acquisition of multi-frequency, multi-incidence angle, multi-polarization SIR-C/X-SAR data in a summer month for vegetation condition and soil moisture assessment, and in a winter month for assessment of snowpack characteristics.
b) Use ARCs and a ground-based scatterometer for absolute calibration of SIR-C/X-SAR imagery.
c) Collect airborne SAR, satellite VIR imagery, and intensive ground data collection to support SIR-C/X-SAR data.
d) Statistical and graphical evaluation of summer SIR-C imagery to isolate changes in backscatter as functions of frequency, incidence angle, and polarization; identify optimum imaging parameters for vegetation characterization and soil moisture assessment.
e) Statistical comparison of near-coincident and temporally different SAR and VIR imagery to determine the degree of synergism/redundancy between the two data types for crop discrimination and condition assessment.
f) Introduction of SAR and VIR imagery (alone and in combination) as surrogates for Leaf Area Index (LAI) in crop yield models and for soil moisture in watershed runoff hydrologic models.
g) Statistical and graphical evaluation of winter SIR-C imagery for snowpack characteristics; assess the feasibility of using SAR imagery as an input to watershed runoff models during periods of snow melt.
III. ANTICIPATED RESULTS
a) At L-band and at small incidence angles for X- and C-band the radar backscatter will be predominantly correlated to soil parameters.
b) Crop yield model performance will improve with the introduction of SAR radar backscatter values as a surrogate for LAI.
c) SAR and VIR data used together will improve crop discrimination over the use of VIR data acquired at a non-optimal period in vegetation development.
d) SAR data will be highly correlated to soil moisture at small incidence angles and, as an input to watershed runoff models, will improve the predictions.
Dip. di Scienze della Terra H. Bork Univ. Braunschweig
University of Florence S. Paloscia CNR-IROE, Florence, Italy
Via La Pira, 4 A. S. Ramoorthi NRSA
50100 Firenze
ITALY
Contribution of SAR for Estimating Soil Erosion
I. OBJECTIVE
a) This research aims to evaluate SAR potential in the study of soil erosion problems.
b) Investigate the contributions of SAR images in reconstructing different stages of transport and redeposition of material on watershed slopes, using models which take into consideration several parameters of soil surface (moisture content, roughness, vegetation cover, etc.) that can be extracted from radar backscattering.
II. APPROACH
a) Extraction of hydrological parameters from SAR data.
b) Validation of erosion models based on SAR data.
c) During the SIR-C/X-SAR mission, the following ground truth parameters will be measured in two sub-areas of the Montespertoli test site chosen for detailed experiments:
Soil Measurements:
-soil moisture content (gravimetric and volumetric) at different depths (5, 10, and 20 cm) using hand augers and in different parts of each field;
-dielectric constant of soils using dielectric probes at different frequencies;
-surface soil roughness, expressed as standard deviation of the heights (hstd and correlation length;
-soil temperature at ~5 cm by a thermometric probe.
Vegetation Measurements:
-crop classification (crop type, variety), height and density of plants;
-sowing date, phenological stage of plants, crop conditions, % weed cover;
-number and dimension (length and width) of leaves, diameter of stems, leaf area index;
-plant water content (kg/m2) computed as the difference between fresh and dry weight of different plant constituents (leaves, stems, ears, etc.).
d) Selected measurements (soil moisture, crop classification, phenological stage, plant height and density) will be carried out over the whole area. Sediment transport measurements will be made at the measuring station on the Virginio stream. Texture and other soil characteristics have already been determined.
e) A digital terrain model (DTM) has been prepared for some areas of Pesa and Virginio basins and some meteorological data are available from three meteorological stations in the area.
III. ANTICIPATED RESULTS
a) Quantitative assessment of the relative contribution of soil and different types of vegetation to the backscattering coefficient.
b) Map geological and erosional features from radar images.
c) Estimate geophysical parameters which are involved in the hydrological cycle (i.e., soil moisture, soil surface roughness, vegetation biomass, etc.).
d) Test and validate models to describe soil erosion processes at basin scale which can use SAR data as inputs.
Marconi Research Centre G. E. Keyte DRA, Farnborough
GEC Research Limited J. R. Baker British National Space Centre
West Hannigfield Road S. Quegan University of Sheffield
Great Baddow G. M. Foody University of Swansea
Essex, CM2 8HN N. J. Veck National Remote Sensing Centre
United Kingdom A. Wielogorska Hunting Technical Services
A Study of the Potential of Multi-component SAR Imagery for Agricultural and Forestry Studies
I. OBJECTIVES
a) The objective of this study is to develop the methods to fully exploit multi-component SAR datasets of agricultural and forestry areas.
b) Determine the radiometric information content of multi-component SAR imagery of agricultural and forested areas by developing backscatter models.
c) Develop techniques for the derivation of specific target information from a multi-component dataset, and consequently determine the optimum set of measurement parameters for use in specifying future SAR missions.
d) Develop improved image processing techniques for the extraction of specific image attributes from these images.
II. APPROACH
a) Obtain multi-polarization images at L- and C-band, and single polarization at X-band, at two incidence angles over the well established Feltwell test site in the UK.
b) Carry out simultaneous ground truth measurements to provide environmental soil, crop, and forest parameters.
c) Provide precise calibration of the SAR images using a combination of ground-based scatterometers and active and passive radar targets.
d) Use statistical, empirical, and semi-theoretical models of radar backscatter to define the radiometric information content of the imagery and to develop data extraction techniques relevant to agricultural and forested areas.
III. ANTICIPATED RESULTS
a) A test of the validity of the use of backscatter models developed from ground and aircraft measurements for representing the measurements from a multi-polarization spaceborne SAR.
b) Development of improved processing tools for extracting information from multi-component SAR images over agricultural and forested areas.
c) Assessment of the effectiveness of a variety of ground based techniques for calibrating spaceborne SAR images.
d) Determination of the optimum SAR measurement parameters and preliminary techniques for monitoring and classifying agricultural and forested areas.
Research Institute Dr. K. Al-Hinai King Fahd University
King Fahd University of Dr. H. S. Edgell King Fahd University
Petroleum and Minerals Mr. M. Khan King Fahd University
Dhahran 31261
SAUDI ARABIA
Geologic and Hydrologic Studies of Saudi Arabia under the Shuttle Imaging Radar (SIR-C) Science Plan
I. OBJECTIVES
a) Use SAR imagery to detect lithological boundaries, distinguish tectonic features, map fluvial geomorphology, and elucidate hydrologic systems within larger areas of Saudi Arabia having a thin sand cover.
b) Establish the Pleistocene paleodrainage system of Saudi Arabia with implications for the hydrology of the country and possibly for archeological geology.
c) Assess the effects of sand terrain diversities on backscatter intensity as a function of radar parameters.
II. APPROACH
a) Multiple polarization radar data is needed from SIR-C/X-SAR to determine buried formation boundaries and discriminate lithologic boundaries, lithologic units, and chemical sediments.
b) Use as broad a swath as possible to distinguish tectonic features, fluvial geomorphology, and hydrologic aspects of paleodrainage.
c) Field observations will be carried out to collect ground truth data on joint systems, fold structures, fault systems, rock types, thickness of sand layer over paleodrainages, dune dimensions and orientation, and vegetation density.
III. ANTICIPATED RESULTS
a) Analysis of SIR-C and X-SAR radar imagery is expected to yield spectacular new information on the geology and hydrology of Saudi Arabia.
b) Major revisions and additions to the existing geological map (USGS Misc. Map 1-270A) and quadrangle maps will be made.
c) Significant new data will be obtained on joint systems and fold structures, as well as some of the major fault systems of Saudi Arabia (e.g., the presently poorly defined east Red Sea Fault, the controversial transcurrent movement on the Najd Fault, and the Amar-Idsas Fault).
d) Establishment of the Pleistocene paleodrainage systems of Saudi Arabia has major implications for Saudi Arabian hydrology. In addition, we expect to be able to contribute to the archeological geology of Saudi Arabia by way of ancient irrigation channels and now buried settlements.
e) Determination of optimum radar parameters for identification and delineation of aeolian bedforms.
Center for Remote Sensing John Melack Univ. of Calif., Santa Barbara
and Environmental Optics Jack F. Paris California State Univ., Fresno
University of California
Santa Barbara, CA 93106
Biomass Modeling of the Ponderosa Pine Forests of Western North America with SIR-C/X-SAR for Input to Ecosystems Models
I. OBJECTIVES
a) Integrate existing forest biophysical measurements in our Mount Shasta test site with calibrated aircraft SAR for development and testing of our forest radar backscatter model in Ponderosa pine forests.
b) In collaboration with Kaschiske (a SIR-C/X-SAR PI) and Christensen, integrate forest biophysical measurements from Duke Experiment Forest and calibrated SIR-C/X-SAR images for model application to loblolly pine forests.
c) Apply model to identify major backscattering components from conifer forests at X-, C-, and L-band and at four polarizations.
d) Develop an algorithm to retrieve forest biomass and structure from SAR images.
II. APPROACH
a) Develop a scattering model of individual trees based on extensive scatterometer and dielectric field measurements. This model should be able to predict the major scattering characteristics of a tree as a single scatterer from its DBH, height, crown structure, dielectric constants, and surface roughness of major components of the tree.
b) Extend our composite microwave backscatter model to include a scene model of forest stands of different densities with backscattering sub-models including both a single tree scattering model and an aggregate model of groups of trees within pixels.
c) Test this composite model by using aircraft imaging radar polarimetry data through: 1) identifying the dominant scatterers in an image configuration from both model prediction and image analysis; 2) comparing the predicted means, variances, and statistical dispersion of backscattering coefficients of test forest stands with actual image data; and 3) estimating forest biophysical parameter through inversion.
d) Test the robustness of our model through sensitivity analysis.
e) Aircraft and spacecraft radar images will be processed to: 1) reduce the illumination effect, speckle, and the angular behavior of backscattering from forests for classification alone or combined with TM images; and 2) enable regression against biophysical parameters of forest stands including tree number, tree height, DBH, and biomass of components of trees.
III. ANTICIPATED RESULTS
a) Further our understanding of the microwave scattering mechanisms of forests with respect to radar wavelength, polarization, and incidence angle with special emphasis on estimation of above-ground biomass with respect to magnitude, patchiness, partitioning, spatial distribution, and height distribution.
b) Provide methods to quantitatively estimate biophysical parameters of forest stands from SAR images as input to a spatially-distributed ecosystem model of western pine forests.
Computer Systems Laboratory A.T.C. Chang Lab. for Terrestrial Physics
Center for Remote Sensing and Walter Good Inst. fur Schnee-und
Environmental Optics Lawinenforschung
University of California Klaus I. Itten Geographisches Institut
Santa Barbara, CA 93106 Christian Matzler Inst. fur Angewandte Physik
Shi Yafeng Inst. of Glaciology and Geocry.
Wan Zheng-ming Inst. of Remote Sensing Apps.
SIR-C Investigations of Snow Properties in Alpine Terrain
I. OBJECTIVES
a) Estimate snow-covered area and distribution of snow water equivalence over alpine drainage basins. Surface material may be trees that are taller than the snow depth, brush or grass that will be covered by the snow, soil, scree, talus or bedrock, or glacier ice.
b) Estimate spectral albedo of snow cover.
c) Model spatial distribution of snow surface energy exchange, melt rate, and snow metamorphism intensively during two-to-four-week periods around SIR-C/X-SAR flights, and less intensively during rest of snow season.
II. APPROACH
a) Use three frequencies on SIR-C/X-SAR to estimate snow water equivalence for dry snow and possibly for wet snow. Use co-registered digital elevation data, derived from low-altitude aerial photographs, from SPOT stereographic coverage, or contour maps, to correct for topographic effects in radar data. Validate measurements with intensive snow surveys coincident with SIR-C flights, and with scatterometer measurements at one site. To insure that results are not site-specific, field and satellite investigations will be carried out in three different mountain ranges with different climates: Sierra Nevada (California), Swiss Alps, and Tien Shan (Xinjiang, northwest China). We also plan to acquire satellite data, but no field measurement s, for a test site in the Himalaya (Tibet, southwest China).
b) Use optical sensor data to estimate grain size of surface snow layer and its contamination by impurities (e.g. dust or soot). Use these parameters to extend albedo throughout the solar spectrum. AVIRIS data will be requested for US. sites and Landsat data for foreign sites.
c) Use frequencies from SIR-C/X-SAR, especially 9.6 GHz, to detect wet snow and estimate liquid-water content, and possibly to identify dry snowpacks with a wet surface layer and wet snowpacks with a dry surface layer.
d) Use satellite or aircraft data, local micrometeorological data, and digital elevation grids to derive basin-wide energy balance model of snowpack.
III. ANTICIPATED RESULTS
a) Evaluate the ability to continuously monitor and model processes in the Earth's alpine snow cover, thus demonstrating the possibility of achieving an important objective that could be supported by the Earth Observing System (EOS).
b) SIR-C measurements of the snow cover will be carefully calibrated with physical measurements of snow characteristics, thus providing excellent data for evaluation of models of the electromagnetic properties of snow.
NASA/Goddard Space Flight Center Thomas J. Jackson USDA/Agr. Res. Service
Greenbelt, MD 20771 William Kustas USDA/Agr. Res. Service
Peggy O'Neill Goddard Space Flight Center
Thomas Schmugge USDA/Agr. Res. Service
Eric F. Wood Princeton University
Applications of SIR-C Synthetic Aperture Radar to Hydrology
I. OBJECTIVES
a) Determine and compare soil moisture patterns within one or more humid watersheds using SAR data, ground based measurements, and hydrologic modeling.
b) Use radar data to characterize the hydrologic regime within a catchment and to identify the runoff producing characteristics of humid zone watersheds.
c) Use radar data as the basis for scaling up from small scale, near-point process models to larger scale water balance models necessary to define and quantify the land phase of GCMs.
II. APPROACH
a) Select and evaluate hydrologic models capable of simulating hillslope flow process and spatially distributed soil moisture.
b) Collect hydrologic data and spatial soil moisture through a ground data collection program during the SIR-C flights.
c) Convert SAR data to estimates of soil moisture in the presence of a vegetation layer through inversion of microwave backscatter models.
d) Compare the three independent estimates of soil moisture (SIR-C derived, model-derived, and ground-data) to evaluate the utility of the SIR-C data.
e) Use radar derived soil moisture data to calibrate models to depict larger scale processes.
III. ANTICIPATED RESULTS
a) Develop a technology for measuring soil moisture in natural catchments for humid regions using spaceborne radar.
b) Develop a new way to characterize the contributing areas of natural, humid zone catchments.
c) Develop a technology for modeling soil moisture distributions in natural catchments based on spaceborne measured data.
d) Develop procedures for parameterizing macro-scale models capable of representing the land phase processes for GCMs.
e) Development of procedures to scale up hydrologic processes from point or small area to catchment scales using SAR data.
f) Validation of vegetation models for estimating the backscatter component of overlying vegetation canopies and the underlying soil condition.
Mail Stop 300-233 William Bull University of Arizona
Jet Propulsion Laboratory Oliver Chadwick Jet Propulsion Laboratory
4800 Oak Grove Drive Diane Evans Jet Propulsion Laboratory
Pasadena, CA 91109 Alan Gillespie University of Washington
Gilles Peltzer University of Paris
Paul Tapponnier University of Paris
Climate Change and Neotectonic History of Northwestern China
I. OBJECTIVES
The goal of the proposed research is to determine the history of Quaternary climate change for a portion of northwestern China for inclusion in global paleoclimate models and reconstructions of the tectonic history of the area and specifically, to:
a) Determine the extended spectral signatures of desert surfaces and landforms of different ages in a few test sites in northwestern China.
b) Use these signatures to map surfaces and landforms related to past climate changes and determine the history of Quaternary climate change.
b) Determine the ages of movements on some of the active faults in northwestern China.
c) Compare surface modification processes that have operated in northwestern China to those in the southwest US.
II. APPROACH
a) Establish a few key "calibration" sites at which ages of geomorphic surfaces will be determined, remote sensing signatures of the surfaces measured, and the variation of surfaces between and within drainage basins examined.
b) Correlate and map geomorphic surfaces over an extended area of northwestern China, using SIR-C, Landsat, and SPOT data to assist in the derivation of a regional paleoclimate chronology.
c) Use maps of geomorphic surfaces to constrain the tectonic histories of one or more faults passing through the area.
d) Compare with results from similar studies in the arid southwest United States.
III. ANTICIPATED RESULTS
a) Maps of geomorphic surfaces with ages attached to them will be a major step toward understanding the climatic history of this region.
b) Comparisons of this climate record with climate records from the oceans and other continents will help advance the global synthesis of climate change.
c) Determination of how unique and how globally representative remote sensing signatures are will directly affect our future ability to extrapolate the signatures to global studies of climate change. Determination of past slip rates on some active faults in northwest China by a knowledge of the ages of offset surfaces.
Hawaii Institute of Geophysics Hans C. Graber Woods Hole Oceanog. Inst.
University of Hawaii at Manoa D. Halpern Jet Propulsion Laboratory
1000 Pope Road B. Holt Jet Propulsion Laboratory
Honolulu, HI 96822
Reconstruction of the Mesoscale Velocity Shear Seaward of Coastal Upwelling Regions from the Refraction of the Surface Wave Field
I. OBJECTIVES
a) Develop an inverse model of the surface velocity from the refraction of surface waves observed on SAR images.
b) Study the limitations of the model owing to total reflection and caustics.
c) Apply the model to study the small-scale velocity structure of upwelling filaments.
II. APPROACH
a) Collect pairs of crossing SAR images to reduce the errors due to azimuth smearing.
b) Compute surface height spectra from the images, identify wavetrains in the spectra, and use the inverse model to compute the velocity field.
c) Compare the results with co-located NOAA infrared images and shuttle hand-held photographs.
III. ANTICIPATED RESULTS
a) Information on the shear distribution of the filaments, and its correlation with wind speed and wave height which is difficult to obtain from in situ measurements.
b) Information on wind inhomogeneities above the filaments.
c) Comparison of the summertime and wintertime flows and determining whether filaments exist in the winter.
d) Comparison of filament structure in the Northern and Southern hemispheres.
Mail Stop 300-235 M. Craig Dobson University of Michigan
Jet Propulsion Laboratory Peter Hoogeboom TNO Physics & Elec. Lab.
4800 Oak Grove Drive Yuhsyen Shen Jet Propulsion Laboratory
Pasadena, CA 91109 Fawwaz T. Ulaby University of Michigan
Charles L. Werner Jet Propulsion Laboratory
Multi-Frequency, Multi-Polarization External Calibration of the SIR-C/X-SAR Radars
I. OBJECTIVES
a) Assess the accuracy at which the SIR-C/X-SAR standard data products can be calibrated through the use of ground calibrators to estimate the end-to-end system polarization calibration constants (or distortion parameters) and incorporate the constants into the data processing.
b) Study the cross-calibration between three multi-polarization systems: SIR-C, the NASA/JPL DC-8 SAR, and the University of Michigan ground-based polarimetric scatterometer.
c) Evaluate the calibration "stability" of SIR-C/X-SAR (measured by variations in the calibration constants) over the range swath width and over a specified distance in azimuth. Variations over a 12-hour period (between ascending and descending passes) will also be studied.
d) Develop a cost-effective calibration plan including development of inexpensive polarimetric active calibrators.
II. APPROACH
a) Calibrate all the calibrators at standard ranges prior to deployment.
b) Use polarimetric active radar calibrators to estimate end-to-end polarization distortion of the SIR-C system. Use the estimated distortion parameters to extract a "best estimate" of the polarization scattering matrix of other ground targets.
c) Deploy inexpensive trihedral corner reflectors to characterize co-polarized channel imbalance in magnitude and phase over an area wider than that covered by the active calibrators in the primary calibration area.
d) Use multi-polarization ground receivers to record the system transmit azimuth pattern at several elevation cuts and to estimate the transmit polarization distortion. Use calibrated multi-polarization ground scatterometers to provide in situ data over extended targets and compare them with SIR-C/X-SAR data of the same targets. Evolve a cost-effective calibration strategy by comparing the "calibrated'' results obtained using different calibration philosophies.
III. ANTICIPATED RESULTS
a) Full polarimetric end-to-end characterization of the SIR-C/X-SAR system in the primary calibration target area within the limitations of instrument inaccuracy. A better understanding of polarimetric calibration of a space-borne microwave synthetic aperture radar.
b) The polarization scattering matrix of targets within the calibration area will be calibrated to 0.4 dB and 5deg. in magnitude and phase, respectively, between polarization components (or channels) and 2.0 dB absolute error in magnitude, at both L- and C-bands. The compensated absolute error in the X-SAR is expected to be 2.0 dB.
Communications Research Laboratory Jun Awaka Communications Res. Lab.
4-2-1 Nukuikitamachi Toshio Iguchi Communications Res. Lab.
Koganei-shi, Tokyo 184 Toshio Ihara Communications Res. Lab.
JAPAN Hideyuki Inomata Communications Res. Lab.
Toshiaki Kozu Communications Res. Lab.
Takashi Kurosu Communications Res. Lab.
Takeshi Manabe Communications Res. Lab.
Harunobu Masuko Communications Res. Lab.
Yuji Miyagawa Communications Res. Lab.
Kenji Nakamura Communications Res. Lab.
Takeyuki Ojima Communications Res. Lab.
Ken'ichi Okamoto Communications Res. Lab.
Toshiyuki Okuyama Communications Res. Lab.
Makoto Satake Communications Res. Lab.
Takeshi Suitz Communications Res. Lab.
Toshihiko Umehara Communications Res. Lab.
Seiho Uratsuka Communications Res. Lab.
Like- and Cross-Polarization Calibration, Topographic Mapping and Rice Field Experiments by SIR-C/
X-SAR
I. OBJECTIVES
Three experiments are proposed: (1) Like and cross-polarization calibration, (2) Topographic mapping, and (3) Remote sensing of rice fields. These experiments have the following objectives:
a) To calibrate SIR-C/X-SAR images relating to backscattering coefficient, to estimate 3-dB resolution and to establish a technique for cross-polarization calibration,
b) To investigate the optimal frequency and a technique for image quality improvement for topographic mapping, and
c) To establish techniques for active remote sensing of crops.
II. APPROACH
a) Corner reflectors and active radar reflectors will be used as standard targets. Image data numbers will be related to backscattering coefficients and 3-dB resolution will be estimated from point target images.
b) Topographic estimates will be made from three-frequency images and compared among each other. An effect of image improvement on topographic estimation accuracy will be evaluated.
c) Multi-frequency and -polarization images will be compared and/or combined to determine optimal parameters for crop field detection and identification.
III. ANTICIPATED RESULTS
a) Evaluate the imaging characteristics of SIR-C/X-SAR.
b) Determine the optimal frequency for topographic mapping will be determined and establish a technique for image quality improvement for more accurate topographic mapping.
c) Improved technique for detection and identification of rice and crop fields.
Dept. of Geological Sciences AJ-20 John B. Adams University of Washington
University of Washington Milton O. Smith University of Washington
Seattle, WA 98195
Alluvial Fan Evolution in the Western Great Basin
I. OBJECTIVES
a) Describe systematic morphologic changes with surface age in terms of multiparameter radar backscatter for dated chronosequences on alluvial fans at one or two sites in the western Great Basin. Compare these changes to chemical weathering patterns observed for the same fans using visible/near-infrared (VNIR) and thermal infrared (TIR) images.
b) Construct a depositional and weathering history for the studied alluvial fans based on SAR, other images, and field investigations; use this to constrain paleoclimatic interpretations for the Great Basin. Use project as prototype for paleoclimate study of entire Great Basin or other geomorphic provinces, where multiparameter SAR data can be acquired regionally.
c) Test the application of spectral mixing analysis on multiparameter SAR images of alluvial fans in arid and semiarid regions. Define radar endmembers (from the spectral mixing analysis) physically, in terms of Bragg scattering, volume scattering, specular and corner reflectors, and dielectric constant, etc. Develop and test mixing models for comparative analysis of images spanning multiple spectral regions.
II. APPROACH
a) Select study site(s) in Owens Valley/Death Valley to exploit existing geomorphic, soils, and geochronology data, for a sequence of alluvial fans deposited during the last 0.5 Ma.
b) Compare spectral differences in VNIR, TIR, and SIR-C SAR images in terms of systematic chemical and morphological differences predicted by current weathering models, given the known ages of the fan surfaces. Make precise measurements of integrated weathering rates for each dated surface, which can then be analyzed jointly to construct a history of weathering rates and rate changes for selected parameters (e.g., oxidation, hydration, clast disintegration and aeolian silt redistribution).
c) Interpret weathering-rate history in terms of climatic factors that promote weathering (e.g., temperatures, precipitation and excess moisture, wind velocity).
d) Collect and independently analyze VNIR, TIR, and airborne SAR images of the study site(s) prior to the mission to test spectral mixing models applied to radar images alone and with other images.
e) Coregister all SIR-C/X-SAR images to digital terrain models, and jointly analyze them using the "hierarchical" or multi-level spectral mixing model.
f) Separately analyze data from limited spectral regions that are affected by one physical process (e.g., absorption by iron oxide in VNIR data, or scattering due to surface roughness in radar wavelengths). This will be followed by analysis comparing and contrasting results for processes affecting more than one spectral region (e.g., topographic texture affects VNIR data by shading, and affects radar data by scattering).
III. ANTICIPATED RESULTS
a) New technique for "unmixing" multiparameter radar images into meaningful components (e.g., volume-scattering surfaces or "vegetation," Bragg-scattering surfaces, etc.).
b) An alternative to "extended spectral signatures" for joint analysis of disparate images spanning multiple spectral regions.
c) Better history of bajada surface evolution than available from chemical weathering studies alone.
d) Improved knowledge of Pleistocene paleoclimate in the western Great Basin.
e) Test predictive models for climate/paleoclimate and for inferences from paleoecological studies.
Mail Stop 300-227 A. K. Gabriel Jet Propulsion Laboratory
Jet Propulsion Laboratory Fuk K. Li Jet Propulsion Laboratory
4800 Oak Grove Drive C. L. Werner Jet Propulsion Laboratory
Pasadena, CA 91109 Howard A. Zebker Jet Propulsion Laboratory
Differential Radar Interferometry
I. OBJECTIVES
a) Test differential radar interferometry as a new monitoring technique for remote sensing of a forest site, a farm site, and a desert site.
b) Generate topographic maps of test sites from radar data.
II. APPROACH
a) Apply differential inteferometry with respect to wavelength at the forest test site, and with respect to time at the farm and desert test sites.
b) Obtain ground truth data at each site during the mission including tree height, species, and density at the forest site, activity at the farming site, and tropospheric water vapor at the desert site.
c) Verify the derived topography against available topographic maps of the sites.
III. ANTICIPATED RESULTS
a) Separate topographic maps of the forested site from L- and C-band data. Measurement of canopy height from the difference between these data sets. Use ground truth data to assess the validity of two frequency interferometry for monitoring canopy height in forested areas.
b) Detect changes of less than one centimeter in the surface of the fields at the farm site. Such changes are expected to depend mostly on the moisture content of the fields, through either dielectric constant changes or physical swelling of the surface induced by water.
c) Since surface disturbances at the desert test site are not expected to occur between successive SIR-C overflights, it is expected that phase changes due to changes in local tropospheric water vapor may be detectable by differential interferometry.
d) Assessment of the strengths and weaknesses of topography derived from interferometric SAR data for different types of surfaces/sites.
Department of Geology Dan Blumberg Arizona State University
Arizona State University A. Dobrovolskis NASA Ames Research Center
Tempe, AZ 85287-1404 James Iverson Iowa State University
Nicholas Lancaster Desert Research Center, NV
Bruce White Univ. of California, Davis
Keld Rasmussen Aarhus University
Haim Tsoar Ben Gurion University
Stephen Saunders Jet Propulsion Laboratory
Eilene Theilig Jet Propulsion Laboratory
Stephen Wall Jet Propulsion Laboratory
Howard Zebker Jet Propulsion Laboratory
Development of a Technique to Relate Eolian Roughness to Radar Backscatter Using Multi-Parameter SIR-C Data
I. OBJECTIVES
a) To develop a technique to obtain values of aeolian roughness for geologic surfaces from values of surface roughness determined from calibrated L- and C- band, like- and cross-polarized, multiple incidence angle radar data from SIR-C.
b) To define the optimal combination of radar parameters from which aeolian roughness can be derived.
c) To gain an understanding of the physical processes behind the empirical relationship.
II. APPROACH
a) Extract average backscatter coefficients from SIR-C SAR images for natural desert surfaces important to the study of aeolian processes.
b) Model statistics of surface roughness with other SIR-C investigators using multiple parameter data sets.
c) Compute statistical descriptions of surface roughness from large- (m) and small- (cm) scale topographic profiles measured in the field on each surface.
d) Calculate aeolian roughness (zo) from time averaged wind velocity profiles measured in the field. Correlate radar backscatter coefficients, aeolian roughness values, and statistical measures of surface roughness and use regression analysis to derive a predictive equation from which zo could be determined using radar.
III. ANTICIPATED RESULTS
a) Determination of an empirical relationship between measurements of surface roughness as detected by the wind and microwave energy.
b) Development of an equation expressing this relationship. This expression will form the basis of a technique for using spaceborne SAR data to determine a roughness parameter for use in aeolian sand transport rate equations.
c) Validate models of aeolian response to surface roughness.
Institute of Remote Sensing Applications Li Xiaowen Nat. Remote Sensing Center
Chinese Academy of Sciences Wan Zhengming Nat. Remote Sensing Center
P.O. Box 775
Beijing 100101, CHINA
Evaluation of SIR-C/X-SAR Imagery for Geologic Studies in China
I. OBJECTIVES
a) Conduct a radar penetration study by measurement of typical surficial covers.
b) Develop theoretical modeling of radar scattering for penetration study.
c) Develop a limited inversion of radar scattering model for applications of SIR-C/X-SAR data.
II. APPROACH
a) Development of a radar scattering model for realistic and simple surficial cover or layers.
b) Conduct systematic field measurements under controlled conditions.
c) Perform airborne measurements over the study areas with the Chinese X-band, quad polarization SAR system.
d) Analyze field and SAR data by a rational combination of physical modeling, statistical modeling, and measurements.
III. ANTICIPATED RESULTS
a) Theoretical/experimental dependence of radar penetration depth on wavelength, polarization, incidence angle, and properties of the medium.
b) Geologic maps over test areas of China based on multiband, multipolarization SIR-C/X-SAR data.
c) Evaluation of the quantitative applications of SIR-C/X-SAR data in combination with satellite and other ancillary data.
Institut fur Hochfrequenztechnik H. Kietzmann DLR, Oberpfaffenhofen
DLR - Oberpfaffenhofen J. Nithack DLR, Oberpfaffenhofen
D Wessling M. Reich Inst. fur Navigation, Stuttgart
GERMANY
X-SAR/SIR-C Radiometric Calibration Experiment
I. OBJECTIVES
a) The main objectives of the DLR/INS experiments are to determine error sources and assess their contributions on the absolute calibration accuracy of the overall system.
II. APPROACH
A series of five different experiments covering internal and external procedures are planned. Oberpfaffenhofen and its surrounding area will serve as a master test site. The five experiments are: 1) Internal calibration; 2) Measurement of operational SAR antenna pattern; 3) Absolute calibration of SAR image data; 4) Mutual radiative coupling of clutter surrounded calibration targets; and 5) Attenuation of microwaves caused by woodlands.
III. ANTICIPATED RESULTS
a) Quantify the sensor impacts on signal quality and separate systematic from statistical error contributions. Systematic errors will be corrected.
b) Comparison of ground truth antenna patterns with predetermined patterns to assess changes due to Shuttle interference, thermal effects, and incomplete deployment.
c) Development of a procedure to scale the intensities of different earth surface object classes in terms of absolute backscatter values.
d) Assessment of the effects of mutual radiative coupling between closely spaced calibration targets.
e) Investigation of the attenuation effects of forests on SAR signals leading to a better understanding of forest SAR signatures.
Department of Geological Sciences Arthur L. Bloom Cornell University
Snee Hall
Cornell University
Ithaca, NY 14853
SIR-C Analysis of Topography and Climate in the Central Andes
I. OBJECTIVES
a) Understand large-scale interactions between tectonic and climatic-controlled erosional processes that created the Andes.
b) Determine the modern and Pleistocene snow-line altitudes and gradients in a poorly known but critical latitude range of the central Andes, and interpret ice-age changes in atmospheric circulation.
II. APPROACH
a) Acquire four adjacent ascending swaths of SIR-C radar imagery, each with at least two look angles, over the central Andes between 23deg. S and 33deg. S.
b) Compile a digital elevation model (DEM) for this poorly mapped region from multi-frequency, dual-polarization SIR-C data.
c) Use the DEM to study heretofore inaccessible mesoscale (10m-10km) topography in relation to spatial variations of rates of erosion and uplift needed to calibrate geophysical models of Andean mountain building.
d) Analyze radar surface-roughness variations on glacial and volcanic landforms in the central Andes, using ground measurements of slopes to correct for backscatter variations by local incidence angles.
e) Integrate SIR-C data into ongoing field research and Landsat TM analysis of Andean relief.
III. ANTICIPATED RESULTS
a) A new understanding of orogenic relief over a large range of spatial frequencies and of the relative importance of tectonic, volcanic, and erosional processes in shaping landforms of different characteristic wavelengths.
b) A useful new digital elevation model of a poorly known region, to combine with LANDSAT TM and field research in ongoing research.
c) A test of climatic change theories concerning the equatorward shift of the southern hemisphere atmospheric circulation over the Andes during ice ages.
Applied Research Corporation
8201 Corporate Drive, Suite 920
Landover, MD 20785
The Joint Analyses of Single-and Dual-Frequency/Experimental Dual-Polarization
SIR-C and X-SAR Measurements in Precipitation
I. OBJECTIVES
a) Determine the vertical and horizontal spatial distribution of hydrometeors in precipitating clouds. Measure the spatial distribution of liquid water and ice in the clouds.
b) Measure and determine the limits of measurement of the polarization characteristics related to the shapes and orientations of hydrometeors in precipitating clouds.
II. APPROACH
a) SIR-C/X-SAR data will be used to determine the total attenuation from precipitation using the signal strength reflected from the earth's surface. This information will be used as a constraint on the radar equation to provide profiles of the extinction cross-section.
b) Data from SIR-C/X-SAR will be used to remove the effect of partial beam filling, to estimate the vertical distribution of the hydrometeors phase, and to provide an independent estimate of the total path extinction. (The results from c) will then be applied to the steps cited in a) and b.)
c) Collect polarization measurements over a wide range of nadir angles to determine the feasibility and limitations for space measurements of differential reflectivity, linear depolarization, and propagation differential phase shift.
d) To more fully understand the precipitation, we will use passive microwave measurements to analyze in conjunction with the radar data.
e) Validate the spatial distribution of rain by (in order of descending reliability):
1. Comparison with rain rates derived from calibrated CAPPI digital ground based radar,
2. Comparison with operational NOAA radar imagery that is distributed digitally,
3. Comparison with spatial rain distributions inferred from visible and infra-red imagery from operational NOAA satellites.
III. ANTICIPATED RESULTS
a) Identification of the effects of precipitation on SIR-C/X-SAR surface measurements.
b) Analytical techniques, such as those used to retrieve rainfall from data collected during the Tropical Rainfall Measuring Mission (TRMM), can be studied before the TRMM launch. Those results will have an ultimate impact on the Earth Observing System (EOS) initiative..
c) As the first precipitation polarization measurements from space, these data will help determine the future potential application for global microphysical measurements from space.
d) Unique radar studies of precipitation may be possible since data may be collected over intense convective systems over which aircraft bearing radars have not been able to fly.
Radar Science Laboratory Norman Christensen Duke University
ERIM
P.O. Box 8618
Ann Arbor, MI 48107
Estimation of Total Aboveground Biomass in Southern United States Old-Field Pine Stand Using SIR-C/X-SAR Data
I. OBJECTIVES
a) Validate a radar tree scattering model using scatterometer and SAR data collected over old-field loblolly pine stands.
b) Determine what short-term physiological changes within loblolly pine forests result in significant changes in radar backscatter signature.
c) Develop a model that predicts the total aboveground biomass as a function of the multifrequency, multipolarization radar signature.
d) Evaluate utility of biomass estimation algorithm utilizing SIR-C/X-SAR data set.
II. APPROACH
a) Collect multifrequency, multipolarization helicopter-borne scatterometer and/or airborne SAR data sets over old-field loblolly pine stands in Duke University Research Forest during three different seasons and on a diurnal basis.
b) Coincident with radar data collection, collect ground-truth data to physically describe loblolly pine test sites.
c) Compare observed [[sigma]]deg. values to those predicted by a theoretical scattering model.
d) Based on modeling results, develop an algorithm which estimates total aboveground biomass for loblolly pines as a function of the radar signature.
e) Evaluate utility of biomass estimation model using radar data collected by SIR-C/X-SAR over loblolly pine test sites located in southeastern US.
III. ANTICIPATED RESULTS
a) An understanding of what forest characteristics within a loblolly pine forest influence radar scattering at X-, C- and L-band.
b) Validation of a theoretical scattering model for the forest geometry of old-field loblolly pines.
c) An evaluation of the utility of multifrequency, multipolarization for estimating aboveground biomass in old-field loblolly pine forests and other pine forests in the southeast US.
Royal Aerospace Establishment J. P. Matthews University of North Wales
Space & New Concepts Department G. J. Wensink Delft Hydraulics. NAL
Farnborough, Hampshire R. Cordey Marconi Research Centre
ENGLAND
An Investigation of the Imaging of Ocean Waves and Internal Waves with SIR-C/X-SAR
I. OBJECTIVES
a) To improve our understanding of ocean-wave imaging by synthetic-aperture radar (SAR).
b) To test the assumptions of backscattering theory with regard to short-wave properties.
c) To develop new techniques for retrieving ocean-wave spectra from multi-parameter SAR.
II. APPROACH
a) Obtain dual-frequency, dual-polarization SIR-C/X-SAR images at a set of crossing-swath locations.
b) Measure long-wave spectra with an array of wave buoys deployed by a ship.
c) Monitor small-scale waves with a stereo-optical system and possibly a laser slope gauge.
d) Obtain additional SAR imagery at different range-to-velocity ratios from an aircraft and ERS-1 for further study of the effects of wave motions.
III. ANTICIPATED RESULTS
a) An accurate empirical model of the dependence of wave-imaging transfer function on radar frequency, polarization and incidence angle.
b) A greater understanding of the roles of short-wave straining and of scatterer motions in providing mechanisms for imaging long waves.
c) An improved knowledge of conditions under which non-linear imaging limits the wave information recoverable from SAR data.
d) Optimum procedures for recovering wave information and recommendations for SAR-system parameters for future missions.
Department of Electrical Engineering
Massachusetts Institute of Technology
Cambridge, MA 02139
SIR-C Polarimetric Radar Image Simulation and Interpretation Based on Random Medium Model
I. OBJECTIVES
a) Demonstrate the applicability of the random medium model in simulating SIR-C imagery.
b) Analyze and interpret SIR-C imagery for remote sensing applications.
c) Investigation of seasonal variations and atmospheric effects.
II. APPROACH
a) Use the random medium model, with extensive ground truth data, to simulate SIR-C multi-frequency, multi-incident angle, fully polarimetric imagery and actual SIR-C data.
b) Develop polarimetric classification and contrast algorithms using simulated images based on the random model, then apply these tools to analyze and interpret SIR-C imagery.
c) Effects of seasonal variations and atmospheric conditions will be investigated by extending the random medium model to multi-layer configurations to facilitate the interpretation of SIR-C imagery.
III. ANTICIPATED RESULTS
a) Predicted multi-frequency, multi-incidence angle, fully polarimetric SIR-C imagery prior to the actual SIR-C mission.
b) Interpret SIR-C imagery with applications to vegetation classification, crop type, snow depth, seasonal and diurnal change studies.
c) Radar image simulation algorithm based on the random medium model for future radar sensor development.
d) Improved radar image processing algorithms for terrain classification.
e) Multi-layer random medium model for general earth terrain scattering.
Center for the Study of Earth from Space Alexander Goetz CSES
Campus Box 449 Franz Leberl VEXCEL
Boulder, CO 80309-0449
Comparative Lithological Mapping Using Multipolarization, Multifrequency Imaging Radar and Multispectral Optical Remote Sensing
I. OBJECTIVES
a) Develop a better understanding of depositional and erosional processes by studying the compositional and geomorphic variation in sedimentary and igneous rocks.
b) Develop a better understanding of the current geomorphic expression of rock surfaces by determining the relationship between lithological variability, weathering, soil development, and vegetation distribution.
c) Use variation in radar backscatter as a function of wavelength, incidence angle, and polarization to characterize the geometry, and indirectly, the composition of rock units.
d) Compare radar characterization with visible/infrared characterization of surface materials for both vegetated and non-vegetated areas.
e) Evaluate multidimensional image processing techniques for analyzing multi-spectral/multipolarization/multi-incidence angle radar data and the utility of precision radargrammetry to improve lithological mapping capabilities. Map the character and distribution of lithological variation with SIR-C/X-SAR data.
f) Provide hands-on radar remote sensing experience to graduate students.
II. APPROACH
a) Field measurements to be collected in situ include geologic maps, surface roughness measurements, dielectric constant measurements, and surface visible/infrared spectral measurements.
b) Ancillary remote sensing data sets will include: AIRSAR data, digital elevation models (DEM), co-registered AVIRIS, TM, and TIMS data, helicopter stereo pairs for selected geomorphic surfaces, and aerial photographs.
c) Use SIR-C/X-SAR data to complement the visible/infrared spectral signatures of specific rock units by characterizing the multispectral/multipolarization/multiple incidence angle radar signatures of rock units by analyzing the effect of surface geometry and composition on radar backscatter as a function of radar polarization and wavelength; and co-registering radar data to visible/near infrared imaging spectrometer data (AVIRIS), Thematic Mapper (TM) data, and Thermal Infrared Multispectral Scanner data (TIMS) to map the distribution and character of surface rock units.
d) Model the relationship(s) between lithological variability, depositional processes, weathering and erosion, soil development, and vegetation distribution.
e) Evaluate multidimensional image processing techniques developed for the analysis of multispectral data sets. Extend the analysis to a regional scale using the SIR-C/X-SAR data.
III. ANTICIPATED RESULTS
a) Detailed regional mapping of lithology and geomorphology that will allow improved interpretation of the geologic history of selected areas in the southwestern United States and northern Sonora, Mexico. An improved understanding of the relations between lithological variation and geomorphic expression of rock surfaces.
b) A better understanding of the relation between multiparameter radar image characteristics to rock, soil, and vegetation physical properties.
c) An improved understanding of the strengths and weaknesses of multi-spectral/multipolarization/multi-incidence angle radar and how it can be used to complement visible/infrared remote sensing data.
d) Innovative image processing algorithms and analysis techniques for multispectral/multipolarization/ multi-incidence angle radar.
Centre d'Etudes Spatiales des Rayonnements P. Hoogeboom Physics and Elect. Lab. TNO
9 Av. Colonel - Roche, B.P. 4346 A. Fiumara Telespazio
31029 Toulouse CEDEX
FRANCE
Relating Radar Backscatter Responses to Woody and Foliar Biomass of Pine Forests
I. OBJECTIVES
a) Demonstrate the use of spaceborne SAR images to detect forest parameters (biomass of different parts of the canopy).
b) Increase the understanding of the interaction between microwaves and vegetation canopies.
II. APPROACH
We propose to use Landes forest, near Bordeaux, South East of France as a test site. Previous work in this area has established an existing dataset. Inversion algorithms developed on the test-site will be applied to SIR-C/X-SAR data acquired on other sites in the world including coniferous forest sites. It is proposed to relate SIR-C/X-SAR data to vegetation parameters and to develop an inversion algorithm as follows:
a) Theoretical model(s) will be developed and validated by experiments performed with airborne and laboratory systems.
b) The output of validated theoretical model(s) will be used :
1. to study the sensitivity of radar backscattering measurements to vegetation parameters;
2. to define validity domains of selected invertible semi-empirical models; and
3. to compute the fitting parameters of semi-empirical models.
c) Inversion algorithms will be developed in specified domains of validity.
d) Applications on SIR-C/X-SAR data.
e) Interactive process to refine the algorithm.
III. ANTICIPATED RESULTS
a) A demonstration of the use of multifrequency, multipolarization, and multi-incidence angle SIR-C/X-SAR data to probe different parts of a forest canopy. Based on past results, we expect to have simple (therefore convertible) models relating the radar responses to total, woody, and foliar biomass of pine forests. These parameters are indicators of forest productivity, tree disease, and stress conditions, and are required for forest and ecosystem monitoring.
Jet Propulsion Laboratory David Atlas Jet Propulsion Laboratory
Mail Stop 300-227 Peter H. Hildebrand Natl. Ctr. for Atmospheric Res.
4800 Oak Grove Drive K. Eastwood Im Jet Propulsion Laboratory
Pasadena, CA 91109 Richard K. Moore University of Kansas
Remote Sensing of Precipitation by Spaceborne Synthetic Aperture Radar
I. OBJECTIVES
a) Demonstrate, as a proof-of-concept, quantitative measurements of rainfall intensity from space using SIR-C / X-SAR data.
b) Demonstrate the use of the synthetic aperture technique to improve the along-track spatial resolution in the presence of rainfall velocity dispersion.
c) Determine the mean rainfall velocity by extracting the Doppler spectrum centroid relative to the surface returns.
d) Study the backscattering and polarization characteristics of the ocean surface echoes at L-, C- and X-band in the presence of rain.
II. APPROACH
a) Collect SAR measurements of both rain and surface echoes at different viewing angles in the presence of precipitation.
b) Compare SIR-C collected measurements to air- and ground-truth rain data obtained at several in situ measurement sites.
c) Compare the SIR-C/X-SAR data over several 'rainstorms-of-opportunity' with available meteorological data.
d) Process SAR measurements at different resolutions, and extract Doppler, backscatter and polarization information from processed data.
III. ANTICIPATED RESULTS
a) Quantitative evaluation of the rainfall rate, average rainfall velocity, and height of rain cloud.
b) Achievable spatial resolution for rainfall measurement applications using synthetic aperture syntheses.
c) Quantitative measure of the modification in the ocean scattering mechanism as a result of the impinging raindrops, and comparison of such results with theory and previously obtained experimental data.
d) Determination of the polarization signature of the ocean and the signature's variation in the presence of precipitation.
Centro de Calidad Ambiantal Antonio Lot National University of Mexico
ITESM Daniel Pineiro National University of Mexico
Sucursal de Correos "J"
64849 Monterrey, N. L., Mexico
Analysis of Optical and Microwave Data to Assess Dynamics of Mexican Tropical Rain Forest
I. OBJECTIVES
The major objective of this research are to analyze the effect of structural differences and successional stages of the tropical forest, on multispectral, multipolarized and multiple incidence angle data.
II. APPROACH
a) Monitor deforestation processes in tropical regions, in terms of the actual distribution and the dynamics of deforestation. This requires assessing the temporal variations of the forest.
b) Monitoring phenological variation during the annual cycle, as well as long-term analysis. This can only be accomplished by establishing data bases that provide accurate information in a timely manner.
III. ANTICIPATED RESULTS
This research will provide basic information about the relationship between forest parameters and spectral response, radar return, and signal polarization. This project will also derive methodologies that will enable the estimation of tropical deforestation and distinguish the primary forest from the different successional stages.
Northern Arizona University Carol S. Breed US Geologic Survey
189 Wilson Canyon Road Hugues Faure University of Marseilles
Sedona, AZ 86336 Bahay Issawi Cairo
Ted A. Maxwell National Air & Space Museum
The Exploration and Reconstruction of the Middle to Late Cenozoic Drainages of the Sahara by Means of the SIR-C Mapping
I. OBJECTIVES
a) Use SIR-C/X-SAR data in a synoptic mode with other remotely sensed data, field, and cartographic data to map relic Cenozoic drainage systems across the Sahara from the Red Sea Hills, Egypt, to the Chad Basin and Atlantic Ocean.
b) Demonstrate applicability of SIR data, used with Landsat, SPOT and high-altitude photographic data, as a new, cost-effective remote geophysical tool for exploration geology.
c) Produce a major report on the distribution of paleodrainages in the Sahara, their relations to the basic tectonic elements of North Africa (basins and swells), and their economic potential.
II. APPROACH
a) Obtain ancillary data including local maps, seismic and drill hole logs, and reports of local researchers, with help of Egyptian and French co-investigators.
b) Use SIR-C/X-SAR along with Landsat, SPOT, and other data to map Tertiary stream courses in areas obscured by windblown sand along gaps between identified paleodrainage segments. Apply results of SIR-A/B image data analyses for well-documented sites in Egypt and Sudan to the interpretation of SIR-C/X-SAR radar images along putative courses of paleodrainages. Analysis of headcut patterns in the Mesozoic and older rocks of this region are the key to this work.
c) Conduct field investigations at critical sites where Cenozoic fluvial deposits (e.g., old stream sand and gravels) are known or are likely to occur. (Outside support from local and US. agencies in African countries will be solicited for detailed subsurface exploration work.)
d) Assess SIR-C signal behavior as it affects our subsurface mapping capability. Fully utilize SIR-C/X-SAR regioal mapping capability.
III. ANTICIPATED RESULTS
a) Major contribution to the knowledge of erosional events from middle to late Tertiary time, which gave rise to the Quaternary geomorphology of North Africa. Hot humid conditions prevailed during most of the Tertiary, whereas progressive desiccation set in during the Quaternary. The effects of this major climatic shift were to preserve the evidence for earlier geologic events beneath a veneer of windblown sand. SIR-C/X-SAR's ability to see through these dry sands makes our proposed work feasible.
b) A major report will be prepared with accompanying maps that we hope will have broad scientific and economic applications (for both the public and private sectors). Prior work in this region has been limited in scope and uneven in quality because of the regions heritage of political fragmentation. SIR-C/X-SAR provides an opportunity for a multi-national effort of regional synthesis for the Saudi Arabian Peninsula.
Department of Biological Sciences Frank Davis Univ. of Calif., Santa Barbara
University of California Judith Meyer University of Georgia
Santa Barbara, CA 93106
Determining the Extent of Inundation on Subtropical and Tropical River Floodplains Beneath Vegetation of Varying Types and Densities
I. OBJECTIVES
a) Develop a procedure for recovering the presence, absence, and patchy presence of water and its spatial distribution beneath different flood plain plant communities of varying crown closures, densities, stand geometries, and canopy states for sites in Georgia. Test the applicability of the procedure to the Amazon and Alligator river floodplains in Brazil and Australia.
b) Modify, extend, and verify the Santa Barbara radar model for different floodplain vegetation types and densities.
c) Test both discrimination procedures and model predictions for leaf-on/leaf-off and water-on/water-off states against SIR-C/X-SAR and aircraft radar images.
d) Couple the above modeling and discrimination procedures for floodwater detection and delineation for input to conceptual flood stage/flood area hydrologic models.
II. APPROACH
a) Simulate returns with and without water, and under different vegetation types, states (with or without leaves), and densities and compare the results so obtained with both aircraft multipolarization/multifrequency radar and SIR-C/X-SAR images in the three study sites in Georgia.
b) Discriminate between vegetation types and density variations within those types, in the presence and absence of standing water.
c) Exploit the multitemporal capability of SIR-C/X-SAR to isolate the effect of standing water under the forest canopy from the effect of vegetation by comparing imagery of the same wetland stands at high, low, and zero water stages, and leaf-on/leaf-off status.
d) Determine detectability threshold of discontinuous floodplain inundation. Determine the effect of canopy variables on the canopy/standing water interaction by interstand comparisons of wetland sites with different stand structures but under identical flooding conditions, i.e., a continuous sheet of standing water. Determine unique multiparameter calibrated radar signatures for the range of combinations of stand structure and percent water cover.
e) Assess the accuracies achievable with various frequency/polarization/angle combinations for determining water cover.
III. ANTICIPATED RESULTS
a) Assist in the process of overarching theory development.
b) Greatly improve the monitoring of wetland hydrological regimes during the EOS era. Provide a quantitative assessment of the accuracies of radar floodwater mapping beneath vegetation canopies.
Johns Hopkins University David Tilley Applied Physics Laboratory
Applied Physics Laboratory David Lyzenga Environ. Res. Inst. of Michigan
Johns Hopkins Road
Laurel, MD 20707-6099
Optimization of SAR Parameters for Ocean Wave Spectra
I. OBJECTIVES
a) Determine the relative contributions from proposed mechanisms for the imaging of ocean surface waves by SARs. These mechanisms include tilt modulation, hydrodynamic modulation, velocity bunching modulation, and the modulations caused by specular and wedge scattering.
b) Establish the dependence upon geometry, radar frequency, ocean wave height, and wind speed and direction of the loss of azimuth resolution associated with SAR wave imaging.
c) Select a set of SAR parameters (geometry, frequency, polarization) that maximizes the fidelity of SAR derived, two-dimensional ocean wave spectra in the context of azimuth resolution limits.
II. APPROACH
a) Strategies for obtaining multi-parameter SAR imagery:
1. Acquire all imagery at multi-frequency and multi-polarization.
2. Acquire imagery in the vicinity of the cross-overs from series of orbits.
3. Acquire imagery at different look angles over several days.
b) Process imagery to produce wave spectra using baseline procedures developed for SIR-B, L-band (HH) data.
III. ANTICIPATED RESULTS
a) Determination of a composite SAR wave imaging model including the effects of all relevant imaging mechanisms.
b) Determination of whether azimuth resolution degradation is alleviated at higher radar frequencies than L-band.
c) Recommendations for SAR geometry, frequency, and polarization to maximize the fidelity of SAR derived wave spectra and alleviate the loss of azimuth resolution associated with high sea states.
Office of the Oceanographer of the Navy Charles Luther Office of Naval Research
US. Naval Observatory O. H. Shemdin Ocean Res. and Engineering
Washington, D.C. 20392 D. Sheres University S. Mississippi
G. Valenzuela Naval Research Lab.
S. Mango Naval Research Lab.
U. S. Navy Investigations
I. OBJECTIVES
a) As part of the SIR-C/X-SAR experiment, the US. Navy intends to conduct several scientific remote sensing investigations through extensive synthetic aperture radar (SAR) measurements and observations of the marine environment. These investigations include:
Current Boundary Imaging with SAR - This investigation will evaluate the detectability of current boundaries using SAR images of the Gulf Stream and in the Gulf of Mexico.
Ocean SAR Imaging in the Gulf of Alaska - This investigation will evaluate the detectability of ship wakes and determine under which conditions wakes are or are not visible. Validate existing theories of the sea surface spectral response at high wave numbers and SAR imaging in high sea states.
b) These measurements will support a continuing program of basic research and advanced development directed toward applying satellite technology to military problems, especially Naval applications, and the use of SAR as a potential tool in support of oceanographic research.
II. APPROACH
a) Obtain ground truth measurements in the vicinity of Cape Hatteras near the western boundary of the Gulf Stream and in the Gulf of Mexico.
III. ANTICIPATED RESULTS
These investigations will employ a variety of technical approaches, combining SIR-C/X-SAR data with intensive, fine-scale in situ measurements and aircraft-derived data and will contribute to:
a) New and/or improved models describing the mechanisms involved in SAR imaging of ocean features and improved definition of the limits of applicability of SAR in a maritime environment.
b) An improved understanding of how current boundaries are imaged with SAR and of the detectability criteria for current boundaries.
c) Advances in the understanding of major physical mechanisms driving the generation, propagation, and dissipation of ocean phenomena, such as swell, internal waves, and near surface fine-scale features.
d) Compilation of SAR images and ship wake characteristics correlated with radar, ship, and meteorological parameters.
e) Improved understanding of the mechanisms responsible for SAR imaging of wake characteristics at L, C, and X-band radar frequencies in different sea states, and evaluation of SAR's potential use in synoptic detection/observation/monitoring.
The University of Kansas Julian C. Holtzman University of Kansas
Center for Research, Inc.
2291 Irving Hill Drive-Campus West
Lawrence, KS 66045
Inflight Antenna Pattern Measurement for SIR-C
I. OBJECTIVES
a) Obtain the vertical antenna patterns of the SIR-C radars to allow improved radiometric calibration of data for other investigators.
b) To determine how much the vertical antenna pattern changes after launch to aid in designing future space radars and to determine if such measurements are needed on all future space radars.
II. APPROACH
a) Measure backscatter from areas that are uniform in the large scale, particularly the Amazon basin.
b) Use this backscatter averaged over strips about one km by tens of km to determine the variation of scattered signal with angle away from the beam center.
c) Convert these averages into antenna patterns.
d) Provide patterns to JPL for use in improving radiometric corrections of images for other investigators.
III. ANTICIPATED RESULTS
a) Antenna patterns that are better than those produced preflight.
b) A measure of the change in antenna pattern between ground and space conditions.
Planetary Geosciences Div. V. H. Kaupp University of Arkansas
University of Hawaii H. C. MacDonald University of Arkansas
2525 Correa Road W. P. Waite University of Arkansas
Honolulu, HI 96822
The Eruptive Styles of Basaltic Shield Volcanoes from Shuttle Imaging Radar-C (SIR-C) and X-SAR Data
I. OBJECTIVES
a) To provide a comprehensive understanding of the distribution of volcanic materials on classic examples of basaltic shield volcanoes in Hawaii, Reunion Island (Indian Ocean) and Galapagos (Eastern Pacific).
b) Interpret the preserved eruptive history of each volcano, draw contrasts between each test site in terms of the role of the tectonic setting on basaltic volcanism, and make inferences about the internal structure of the volcano and its magma chamber.
II. APPROACH
a) Develop criteria for the discrimination of volcanic materials (lava flow types and ash deposits) using multi-parameter SIR-C/X-SAR data. Determine the optimum frequencies, polarizations and incidence angles from the first SIR-C/X-SAR mission, and obtain data for each volcano during the second mission in mapping-mode with fixed radar parameters. Aircraft SAR data from NASA's DC-8 will be used to help develop these optimum radar parameters, as will field measurements of local topography and dielectric constant.
b) Investigate the complete radar scattering matrix for the volcanic surfaces, using the phase information contained within the quad-pol SIR-C data. The radar data will be used to map the distribution of volcanic materials, and these maps will then be interpreted by both photogeologic and field methods to assess the style(s) of emplacement of lava flows and ash deposits at each test site.
III. ANTICIPATED RESULTS
a) If Kilauea volcano is still active during the mission, we expect to test the first near real-time tracking of an active lava flow using radar. Radar scattering work in Hawaii will allow us to quantify the types of lavas seen on other terrestrial volcanoes, thereby permitting an assessment of the eruption rate of magma on some less well studied volcanoes.
b) Work in the Galapagos will permit details of the structure and eruptive history of the seven active volcanoes to be interpreted and compared to active volcanoes in Hawaii and the Reunion Islands. Maps of lava flows, craters, fissures, etc. of the volcanoes in Kamchatka will greatly improve our knowledge of these poorly known volcanoes.
c) Compare the roles of tectonic setting and spatial variations in activity in a way that has not been possible before using a uniform data set for physically separated landforms.
d) To obtain this regional view, we will develop radar scattering models that enable us to take local test data and extrapolate these observations to the regional scale. Such methods are deemed to be particularly important as the geologic community prepares itself not only to study geographically-isolated terrestrial landforms using ERS-1, JERS-1, and EOS data sets, but also in the analysis of planetary volcanic terrains such as those investigated on Venus by NASA's Magellan spacecraft.
Istituto U. Nobile J. Nithack DLR Oberpfaffenhofen
Piazzale V. Tecchio, 80 K. Krishnanunni Indian Space Res. Organization
80125 Napoli, ITALY F. Jaskolla University of Munchen
Geology of the Campanian Test Site
I. OBJECTIVES
The proposed experiments will evaluate the capabilities of multiple parameter spaceborne SAR in geological, agricultural, and oceanological applications at the Campanian Test Site (Southern Italy).
II. APPROACH
The proposed research aims at a large scale and multidisciplinary study of the whole region, using the specific acquaintances and synergistic studies of the researchers working in diverse scientific disciplines. A global geological, hydrogeological, agricultural, marine and coastal area study using SAR data and optical imagery is planned.
III. ANTICIPATED RESULTS
It is expected that by using L, C, and X band imagery, all the necessary information on the geometry of the area will be obtained. The aim of the research is a regional reconstruction of the structural and volcano tectonics setting and its correlation with plate-tectonics and earthquake epicenter. This will permit the drawing of updated structural and hydrogeological maps.
Department of Geography Walter E. Westman Univ. of California, Berkeley
California State University
Fresno, CA 93740-0069
Global Biodiversity: Assessment of Habitat Change and Species Extinctions with Multiparameter Synthetic Aperture Radar (SAR) Data
I. OBJECTIVES
a) Study the impact of tropical forest fragmentation on local populations of endangered and threatened species of certain mammals, butterflies, birds, and plants. Vegetation information from SIR-C/X-SAR data over three tropical-forest intensive-study sites will aid an independent, broader study of forest fragmentation and its effects on biodiversity.
b) Add the unique, detailed information on forest fragmentation from spacecraft-based SAR to the broader study begun in 1988.
c) Use imaging data from the Landsat Multispectral Scanner (MSS) and the National Oceanographic and Atmospheric Agency (NOAA) Advanced Very-High Resolution Radiometer (AVHRR) to assess on a biome scale, but with less spatial resolution than that of the SIR-C/X-SAR data.
d) Evaluate the use of the unique information about forest distributions and stand conditions expected from multiparameter synthetic aperture radar (SAR) relative to that from the MSS and AVHRR.
II. APPROACH
a) Species diversity and population dynamics are affected by the size, degree of isolation, and condition of forest habitats.(e.g., due to cultural deforestation or natural disturbances such as fire). The broader project will predict the changes in endangerment status of mammals, birds, butterflies, and certain plant groups in the subject tropical areas. To assess the impact of remotely-sensed forest changes, the investigators in the broader study will use a combination of ecological simulation modeling, biogeographic theory, a global georeferenced database of species occurrence, abundance, and habitat preferences, and field data on the response of subject species to habitat fragmentation.
b) While much information is expected from the independent study through the use of data from the MSS and AVHRR, SIR-C/X-SAR data will provide unique information about forest conditions. A biome-wide study using SAR could not be done with the limited SIR-C/X-SAR data (taken over two one-week periods); this broader application of SAR data, if proven feasible in the SIR-C/X-SAR project, would have to await EOS SAR or other long-term radar systems to be in Earth orbit in the 1990's and beyond.
1. Specifically, data from the multiparameter SIR-C SAR [especially from L-band multipolarization channels] will be useful in distinguishing between closed forest (100% canopy closure), woodland (50-99% canopy closure), open woodland (10-49% canopy closure), shrub land, and grassland. Furthermore, we expect quantitative information on early forest regrowth.
2. Recent results (Ulaby, et al., 1986) from studies of textural information in a block of SAR pixels suggests that forests of different types and stages of maturity may have qualitative differences in textural properties useful for forest-habitat characterization. Differentiation of successional stages of recovery in the tropics will add to model precision, both for the biodiversity project and for other research goals. Also, if standing water exists beneath forests, L-band SAR data often responds (presents a brighter image) in a way that such areas can be delineated.
III. ANTICIPATED RESULTS
a) Provide valuable, relatively high spatial resolution information about forest fragmentation conditions for use in refining such estimates based on MSS and AVHRR data.
b) Provide valuable insight into the extended and broader area usage of spacecraft SAR data (e.g., from the EOS SAR) for studies of tropical forest type classification, biodiversity, and species loss in future years (i.e., during the EOS era).
c) Promote the use of remotely-sensed data for the study of an important ecological issue -- the impact of cultural activities on forest habitats and on the threatened and endangered species that reside in these.
Department of Land, Air & Water Resources Roger Shaw Univ. of California, Davis
Univ. of California, Davis Susan Ustin Univ. of California, Davis
Davis, CA 95616
Turbulent Exchange at Vegetated Surfaces and Evaluation of Estimates of Canopy Structure Using SIR-C Data
I. OBJECTIVES
a) To characterize the turbulent exchanges of momentum, heat and gases from plant surfaces.
b) To evaluate the effects of foliage density, structure and height on the exchanges.
c) To evaluate the use of SIR-C/X-SAR remotely sensed data for estimating information regarding the type, structure, and status of vegetation needed for estimating the exchanges of momentum, heat and gases.
II. APPROACH
a) Field experiments will examine the nature of turbulent structures which transport carbon dioxide, water vapor, heat, and momentum. The effects of the canopy structure on turbulence will be determined.
1. Fast-response sonic and infrared sensors will provide turbulence and flux data. These data will be used to identify coherent structures and establish relationships between turbulent flow statistics.
2. A higher-order closure model describing the soil-plant atmosphere continuum will be used to interpret the data.
b) We will determine the feasibility of using SIR-C/X-SAR data for measuring the canopy structure in field experiments coupled with (a).
1. SIR-C/X-SAR data will be corrected. Microwave and TM (or other optical data) will be used to produce a canopy structure map.
2. The utility of SIR-C/X-SAR, ground-based microwave, and aircraft-based SAR data will be evaluated using conventional measures of canopy structure.
III. ANTICIPATED RESULTS
a) The fluxes of gases, momentum, and heat from vegetated surfaces will be estimated with greater accuracy using the results of the micrometeorological experiments.
b) The effects of canopy structure and roughness on turbulence and fluxes will be established.
c) Limitations of using microwave data to measure plant structure will be identified. Recommendations for future instrument usage and design will be made.
Geo Eco Arc Research Lorrain Giddings Goddard Space Flight Center
La Cañada, CA Jack F. Paris California State Univ., Fresno
Byron L. Wood NASA, Ames
Radar Investigations of Wetland Hydrology in the Seasonal Tropics
I. OBJECTIVES
a) Develop a model of multiparameter radar backscatter from wetland vegetation and substrates.
b) Characterize seasonal hydrological changes in tropical wetland ecosystems on a regional scale with multitemporal and multiparameter radar data.
c) Determine the relationships between hydrological regime and species composition, physiognomy, phenology, and biomass of tropical wetlands.
d) Gather information important to mitigating human impact on tropical wetlands and future reduction of vector-borne disease.
II. APPROACH
a) Adapt existing models of microwave scattering and absorption to the study of wetland ecosystems.
b) Select a test site based on scientific objectives, existing data, and foreign collaborators, deployment constraints of DC-8 SAR, and coordination with other SlR-C/X-SAR investigators.
c) Acquire vegetation, hydrology, DC-8 SAR, SIR-C/X-SAR, and space and airborne multispectral optical data of test site covering an annual cycle (two DC-8 and two SIR-C/X-SAR missions).
d) Verify backscatter model with field, optical, and SAR data.
e) Determine seasonal changes in wetland hydrology and vegetation and their relationship to one another.
III. ANTICIPATED RESULTS
a) Use our backscatter model, field and optical data to isolate unique SAR backscatter signatures for changes in wetland inundation and soil moisture.
b) Construct four thematic maps of the test site depicting seasonal changes in wetland hydrology and vegetation.
c) Demonstrate correlations between hydrologic regime and wetland vegetation and infer causal relationships.
d) Establish a basis for future multitemporal multisensor studies of wetlands with the Earth Observing System (EOS).
RADARSAT C. S. Nilsson CSIRO-Marine Lab., Aust.
110 O'Connor Street, Suite 200
Ottawa, Ontario K1P OY7
CANADA
Synthetic Aperture Radar Ocean Imaging Physics
I. OBJECTIVES
a) Gain a better understanding of SAR ocean surface imaging physics by comparing SIR-C/X-SAR data, coincident airborne SAR under flights, perhaps coincident ERS-1 SAR data, and in situ directional wave spectrum measurements and ocean observations.
b) Study surface gravity waves, internal waves, mesoscale features, wind signatures, and ship detection.
II. APPROACH
a) Four study sites will be selected. The first site corresponds to a nominally winter SIR-C/X-SAR flight, and is centered upon the edge of the marginal ice zone off the coast of Newfoundland in the Atlantic Ocean. The second site corresponds to a nominally summer SIR-C/X-SAR flight, and is off the West coast of Vancouver Island near the entrance of Juan de Fuca Strait in the Pacific Ocean. The third site is in the Tasman Sea and the fourth site is the East Australia Current. These four study sites will present a variety of ocean features and conditions for study in a multi-sensor experiment.
b) The ocean wave analysis will center around conversion of SAR imagery into reliable directional wave height spectra. Particular emphasis will be placed upon inter-sensor comparisons, and the inclusion of optimal SAR processing schemes such as adaptive multi-look processing and the explicit inclusion of noncoherent scene motion effects.
c) Mesoscale ocean features will be tracked via AVHRR imagery and subsequently searched for in the resulting SAR imagery. Internal gravity wave signatures will be analyzed for wavelength and corresponding propagation velocities will be compared with those predicted by in situ CTD surveys. Wind signatures will be searched for in the data and correlated with the winds predicted by surface pressure maps. Ship detection exercises will be based upon observations of the research vessels present in the study site, and any chance observations of icebergs in the winter study site.
III. ANTICIPATED RESULTS
a) Improved understanding of the SAR imaging of ocean surface waves, particularly the dependence of aspects of the SAR geometry, operating configurations, and SAR processing upon the image fidelity of surface gravity waves with an azimuthal wavenumber component.
b) Optimal SAR geometries and processing schemes for the observation of internal waves, mesoscale features, wind signatures, and hard targets in sea clutter will be established.
Biospheric Sciences Branch-Code 923 Guoqing Sun Science Systems Applic., Inc.
Goddard Space Flight Center Herman H. Shugart University of Virginia
Greenbelt, MD 20771 James A. Smith Goddard Space Flight Center
Imaging Radar Data Analysis for Forest Ecosystem Modeling
I. OBJECTIVES
The overall objective of this proposed work is to capitalize on and develop the unique advantages of satellite imaging radar data combined with models of forest ecosystem dynamics for characterizing northern/boreal forest ecosystems, especially with regard to the interpretation of landscape patterns and processes at local and regional scales. Specific objectives are:
a) Use radar observations to help infer where landscape pattern and process ecosystem models succeed or fail at regional spatial scales and inter-annual temporal scales.
b) Use radar data to check potentially observable forest ecosystem model predicted attributes.
c) Use radar observations and models to extract biophysical properties of forest canopies, soils and hydrologic parameters used in our forest ecosystem models.
II. APPROACH
a) Use standard SAR image processing and analysis techniques (e.g., to first extract radar channels and then map the changes in composition, species and gap size distributions) to characterize ecosystem states over selected and modeled study sites. AIRSAR aircraft missions over our intensive sites will be used to guide our later satellite radar analyses.
b) Analyses of field and aircraft data collected over our study sites will be used to explore quasi-statistical relationships between measured response and ecosystem attributes. These relationships may then be applied to satellite collected data to make more detailed checks on ecosystem model performance.
c) Physically based radar models will be applied to existing and field collected data over subsets of our study sites to examine radar and optical scattering from different scene components, useful for objectives a) and b) above, and to develop model inversion strategies for selected ecosystem model input parameters.
III. ANTICIPATED RESULTS
a) The utility of space-borne SAR for guiding the conditions under which ecosystem model assumptions can be relaxed, or conversely, where new mechanisms must be incorporated into models applied at these relatively unexplored spatial scales will be demonstrated.
b) A further tool for evaluating detailed model processes will be explored especially in the regional spatial domain where more traditional methods are difficult to apply.
c) Extract canopy structural parameters from radar observations which can be applied to optical radiative transfer models important for calculating the internal and external radiation regime, or vice versa.
University College London Wyn Cudlip University College London
Mullard Space Science Lab Myszka Guzkowska University College London
Holmbury St Mary, Dorking Ian Mason University College London
Surrey, RH5 6NT Jeff Ridley University College London
UNITED KINGDOM
Combined Altimetry and SAR Imagery of a Desert Test Site
I. OBJECTIVES
a) To carry out a technical and geophysical investigation of scanning-beam, beam-limited altimetry using SIR-C/X-SAR at vertical incidence angle over a well-characterized desert site.
b) To evaluate and compare the height information obtainable from SAR-interferometry and SAR-stereo over the selected desert test site.
c) To obtain multi-frequency, multi-polarization, multi-look angle SAR images of the desert test site covering several surface types, to investigate the surface and subsurface features and properties which can be measured, and to define optimum observing parameters.
d) To evaluate the role of satellite remote sensing, and satellite altimetry and SAR in particular, to improving the understanding of the geomorphological processes of erosion, transportation, and deposition in arid regions. To develop and validate analysis techniques with global applicability for the study and monitoring of desert processes, particularly those associated with climate change.
II. APPROACH
a) A test site in the Central Australian desert will be selected using Seasat and Geosat altimetry data, Landsat imagery, aerial photography, and surface reconnaissance. Surface measurements will be made, including Ku-band scatterometry, and the measurement of surface geometry, soil type, grain size, dielectric properties, moisture content, and vegetation cover. A network of control locations will be established to standardize subsequent field measurements. Additional surface measurements will be carried out during overflights.
III. ANTICIPATED RESULTS
a) Demonstration of scanned-beam, beam-limited altimetry and along-track synthetic aperture processing resulting in improved specifications for future instruments. A quantitative assessment of SAR-interferometric and SAR-stereo height estimation.
b) Improved understanding of the radar backscatter mechanism from homogeneous, rough surfaces, particularly at vertical incidence angles. An improved understanding of the information content of SAR imagery of arid regions, and the specification of optimum observing parameters for desert imagery.
c) Develop an improved digital terrain model (DTM) for the desert test site, including topography and surface/subsurface characteristics such as surface roughness, soil type, moisture content, and vegetation cover.
d) The development and validation of techniques and methodologies for the determination and monitoring of desert morphological processes, particularly those related to climate change.
Institute for Meteorology and Geophysics M. Buchroithner Research Ctr. Joanneum
University of Innsbruck C. Matzler University of Bern
Inrain 52 O. Reinwarth Bavarian Academy of Sciences
A-6020 Innsbruck, AUSTRIA
High Alpine SAR Experiment
I. OBJECTIVES
a) Carefully surveyed test sites in the Alps are proposed as model sites for applications of multi-parameter SAR in high alpine areas.
b) Using extensive comparative data to gain a better understanding of the SAR response to physical target properties and improve the methods for SAR data analysis. The experiment will emphasize the following topics:
1. Monitoring of glacier properties and seasonal snow cover,
2. Mapping geological and erosional features,
3. Topographic mapping from radar stereo imagery, and
4. Mapping alpine vegetation and sub-alpine forests.
II. APPROACH
a) The physical properties and the back scattering signatures of the main targets will be measured on the ground and compared with the multi-parameter SAR signatures.
b) Digital elevation data, detailed thematic maps, and field measurements will be used for data analysis and validation. Airborne imagery and optical satellite imagery will be obtained for comparison and will be used for generating multi-sensor data sets.
c) SAR images will be geometrically rectified and synthetic radar images will be generated as the basis for quantitative analysis of the SAR data.
d) Topographic mapping will be carried out for different SAR stereo-models (SAR channels, look/intersection angles). Methods of direct thematic mapping through on-line stereo-restitution will be tested.
III. ANTICIPATED RESULTS
a) Improved understanding of spaceborne SAR's ability to detect physical properties of the seasonal snow cover, of glaciers, and for deriving geological and erosional features.
b) Evaluate the feasibility for extracting information on alpine vegetation and sub-alpine forests from multiparameter SAR data.
c) Improved digital methods for thematic mapping of glaciers, snow cover, geologic structures and erosional features. Improved methods for high-precision contour and line mapping using radar stereo imagery and the assessment of mapping accuracies.
d) Evaluate the possibility of external radar calibration through backscatter measurements on homogeneous glacier areas.
e) Determine the optimum SAR parameters for future advanced earth observation systems regarding operational tasks in alpine terrain.
US. Geological Survey Carol Breed US Geologic Survey
2255 North Gemini Drive Philip Davis US Geologic Survey
Flagstaff, AZ 86001 Hany A. Hamroush Cairo University
Bahay Issawi Cairo
Nicholas Lancaster Arizona State University
John McCauley Northern Arizona University
Michael N. Machette US Geologic Survey
Gary Olhoeft US Geologic Survey James T. Teller University of Manitoba
Justin M. Wilkinson University of Chicago
SIR-C Surface and Subsurface Responses from Documented Test Site Localities in the Sahara, Namib, and Kalahari Deserts, Africa and the Jornada del Muerto, New Mexico
I. OBJECTIVES
a) To determine the optimum SIR sensor configuration for detection of desert duricrust and to use this understanding to reconstruct the paleoclimatic history of two large desert regions in Africa.
b) To determine the ability of SIR-C/X-SAR (alone and synergistically with other remotely-sensed data) to delineate and map near-surface, regional caliche deposits and other "fossil" duricrusts formed during a series of less arid intervals in Africa, but now obscured by aeolian sand.
c) To test various sensor parameter configurations of SIR-C/X-SAR for discriminating among surface and near-surface stratigraphic units in well documented sites from the SIR-A and SIR-B experiments. The results will be used to calibrate the penetration and backscattering capabilities of the SIR-C/X-SAR.
II. APPROACH
a) Extend laboratory measurements and the SIR-A/B geometric scatter model for calichified sediments in arid, sand-covered terrains to higher frequencies and a wider range of sample physical parameters. Refine and use digital-image-processing procedures developed following SIR-A/B to discriminate and map the distribution of caliche deposits and other surface and subsurface units using coregistered composites of SIR Landsat Thematic Mapper (TM) and SPOT image data.
b) Using well-understood African and United States sites, document and establish limits on SIR-C/X-SAR signal behavior in hyperarid-to-semiarid regions. Specifically, evaluate the effects of surficial/subsurface geologic conditions on SIR-C response in various sensor configurations.
III. ANTICIPATED RESULTS
a) An improved understanding of radar backscatter and penetration in hyperarid-to-semiarid terrains that was initiated during our SIR-A/B investigations. Improved models of geometric scattering effects on SIR signal penetration.
b) Refinement of synergistic remote methods to identify various types and stages of datable, authigenic CaCO3 deposits related to successive changes in climate and surface geologic processes during the Quaternary. Significant new data on the spatial and chronological distribution of semiarid paleoclimatic zones in Africa.
Instituto de Pesquisas Espacias H. J. H. Kux University of Freiburg
Ave. Dos Astronauts, 1758
Caixa Postal 515, 12227-010
São José dos Campos
S.P. BRAZIL
Microwave Remote Sensing Data from a Spaceborne Platform as a Tool to Monitor the Hydrological Cycle of a Floodplain Area ("VARZEA") at Northeast Brazil.
I. OBJECTIVES
a) To develop an algorithm to monitor the hydrological cycle over agricultural areas, based on data derived from SAR imagery and meterological data at a floodplain area ("varzea") in Northeast Brazil (Pernambuco State).
b) To evaluate the possibility of discriminating among cultures at the time of the SIR-C/X-SAR overflight To describe and analyze the attenuation properties of the cultures as related to radar parameters including frequency, polarization, and incidence angle.
II. APPROACH
a) Conduct the SIR-C/X-SAR study at the Bebedouro Irrigation Project in northeastern Brazil. This project has been developed to improve and develop new agricultural and cattle raising techniques for the dry sections of Northeast Brazil, and specifically to study problems related to soil hydrology, soil moisture and dryness, evapotranspiration and soil and water salinization resulting from improper irrigation practices.
b) Acquire in situ data during the mission including meteorological data, depth of water at site, and soil sample analyses.
III. ANTICIPATED RESULTS
a) Establishment of a methodology to estimate soil moisture and evaporation rates at a regional scale for irrigation projects, climatological studies, and as an input to numerical models for weather forecasting, based on operational SAR systems such as the Earth Observing System (EOS).
b) Development of a data base relying on a multiparameter SAR system and its interaction with different tropical agricultural crops.
c) Development and acquisition of software for the classification and enhancement of digital SAR images to assist in agricultural and hydrological studies in the future.
Center for Lithospheric Studies Timothy H. Dixon Jet Propulsion Laboratory
University of Texas at Dallas Kent C. Nielson University of Texas at Dallas
Box 688 Mohammed Sultan Washington Univ., St. Louis
Richardson, TX 75083
SIR-C Studies of the Precambrian Hamisana and Nakasib Structures, NE Sudan, in Arid Regions of Low Relief and in the Subsurface
I. OBJECTIVES
a) Develop techniques for optimizing structural analysis of basement trends in arid regions with extremely subdued topography and/or thin aeolian cover.
b) Apply results of a) to map the southern extension of the Hamisana Shear Zone and the western extension of Nakasib Suture.
c) Apply results of b) to constrain the roles of terrane accretion and strike-slip re-organization for late Precambrian crustal evolution in NE Africa.
II. APPROACH
a) Pre- and post-mission field studies will focus on defining the major basement structures of the NE Sudan to determine their deformational history and orientation of structural fabrics.
b) Interface with ongoing LANDSAT TM and field studies of the Hamisana Shear Zone and initiate similar studies for the Nakasib Suture. Ancillary data is also requested (i.e., hand-held photography, large format camera).
c) During the first SIR-C/X-SAR flight, we will determine the best configuration of radar parameters for resolving the structures in the study area. The following will assist in this determination.
1. Dual frequency (L-and C-band or L- and X-band), like polarized (V-V or H-H). Penetration is inversely proportional to frequency, so comparison of L with C- or X-bands should allow discrimination of surface vs. subsurface effects.
2. Single frequency (L-band), dual polarization (V-V or H-H) and (V-H or H-V). This will allow examination of possible polarization effects in subsurface and near-surface features.
3. Incidence angle should be as high as possible, to mimic as much as possible a SEASAT imaging configuration. This will maximize weak returns off the subsurface and will enhance subtle topographic features in this low relief terrain. Some of these may have structural significance due to preferential erosion.
d) Second flight experiment should get coverage over the same area using approaches iv) a) and b), to the extent possible to determine the best configuration for the subsequent experiment.
III. ANTICIPATED RESULTS
a) Better understanding of the southern continuation of the Hamisana Shear Zone and the western continuation of the Nakasib Suture and the sequence of deformational events (collisions, strike slip faulting, etc) that led to the formation of the continental crust of this poorly known region. This will better constrain models linking the major basement structures of NE Africa and those of the Mozambique Belt of East Africa.
b) Better understanding of the imaging techniques necessary for elucidating buried and low-relief structures in arid terrains.
c) Better understanding of the radar signature of suture zones and strike-slip zones of deformation in terrains and climates analogous to those expected on planetary surfaces such as Venus.
Dept. of Applied Geology E. H. Fooks Univ. of New South Wales
Univ. of New South Wales J. Leach CSIRO
P.O. Box 1 A. K. Milne Univ. of New South Wales
Kensington NSW 2033 J. Acworth Univ. of New South Wales
AUSTRALIA J. Odins Water Res., New South Wales
The Evaluation of SIR-C Imagery for Surficial Sediment Mapping and Groundwater Management in Australia
I. OBJECTIVES
a) To assess the utility of multipolarization multifrequency spaceborne radar for surficial sediment mapping (4.2.5.3. lithology, rock weathering and geochronology, Science Plan) and groundwater management (4.3.5.1, arid regimes, Science Plan) in a variety of Australian environments.
b) To establish the utility of the SIR-C imagery for recognizing basement structures (4.2.5.4, tectonics and geologic boundaries, Science Plan) by mapping drape-related fractures in overlying surficial sediments.
II. APPROACH
a) Sites have been selected across Australia so as to cover a range of sedimentary environments from arid to temperate.
b) Sites at Kerang, Palm Valley, Fowlers Gap, Cooper Creek, Lake Eyre and Condobolin contain Precambrian and Devonian sediment outcrops, Tertiary and Quaternary sediments, and fresh and saltwater lake systems. A large data base of remotely sensed imagery covering these regions is already available.
c) The study will involve image analysis and enhancement. Detailed ground investigations will involve petrology, surface roughness determinations, moisture measurements, dielectric constant determinations, salinity analyses, and signal calibration.
d) Studies will be extended along swath into differing hydrological environments each with particular water-management problems. Sites within the Murray Darling Basin, Cooper Creek/Diamantina Rivers and Simpson Desert will be included.
e) Block faulting in Devonian to Cretaceous age sediments in petroleum bearing sediments in the Cooper and Eromanga Basins is propagated upwards into overlying Tertiary to recent sediment cover. Comparative studies of these drape-related features employing lineament analyses from several remotely sensed data bases and the SIR-C/X-SAR imagery will be carried out at along-swath study sites.
III. ANTICIPATED RESULTS
a) Map surficial deposits of different type and age by surface roughness, sub-surface volume scattering, cross-polarization returns and phase difference images. These maps will have important consequences for the recognition of potential aquifer materials in arid and semi-arid regions.
b) Map seepage zones in areas of internal drainage and saltlake formation using variations in dielectric constant to determine moisture contents and conducting salt layers. These maps will be important to understanding natural salt-lake systems and salinity management in irrigation areas such as the Murray Darling Basin and elsewhere in the world.
c) Demonstrate that spaceborne radar is a powerful tool for mapping basement tectonic features through overlying surficial sediments. While having implications for petroleum exploration, this will also be important for recognizing high permeability zones for the siting of water wells.
d) Test the effect on varying amounts of vegetation cover on our ability to achieve these results.
University of Michigan M. Craig Dobson University of Michigan
Radiation Laboratory T. Sharik Michigan Technical University
Department of EECS J. A. Weber University of Michigan
1301 Beal
Ann Arbor, MI 48109-2122
Polarimetric Radar Observations of Forest State for Determination of Ecosystem Process
I. OBJECTIVES
a) The objectives of this research are to test the hypotheses that ecologically significant forest state parameters may be estimated from SAR data. These include estimation of above ground biomass, plant water status, and near surface soil moisture under certain forest conditions.
b) Test hypotheses in the northern hardwoods forest community, refine them if necessary, and establish techniques for retrieving this information from orbital SARs such as SIR-C/X-SAR.
II. APPROACH
a) The study will be conducted in three phases as follows:
1. Monitor the dielectric and geometric properties of selected forest canopies on a diurnal and seasonal basis. Use these values to simulate radar backscatter as a function of frequency, polarization, incidence angle, and range into the canopy as a function of time using the Michigan Microwave Canopy Scattering Model (MIMICS). Simulations will be evaluated on the basis of concurrent multifrequency, polarimetric backscatter observations using AIRSAR.
2. Refine initial hypotheses on the basis of sensitivity studies generated using MIMICS for a range of forest stand conditions existing at the test site area near the University of Michigan Biological Station (UMBS). Studies will use databases established at UMBS over the last 78 years. An airborne SAR program will be conducted prior to SIR-C/X-SAR to test these hypotheses under heterogeneous field conditions and evaluate retrieval techniques derived from inversions of the MIMICS model.
3. Demonstrate the utility and the lateral geographic extendibility of these retrieval techniques beyond the study region using SIR-C/X-SAR data. Issues of sensor calibration are critical to this phase and on-site external calibration techniques will therefore be applied throughout the experimental program.
III. ANTICIPATED RESULTS
a) Determination of the dynamic range of radar backscatter from northern hardwood canopies in response to diurnal, daily, and seasonal dynamics.
b) Validation of a robust forest canopy scattering model (MIMICS) which can then be applied to other forest conditions.
c) Definition of the retrieval techniques and their respective accuracies. Evaluate the limitations for each hypothesis.
Cattedra di Ingegneria dei D. Solimini University Roma
Sistemi Aerospaziali
Facolta di Ingegneria
Piazzale Tecchio, 80
80125 Napoli, ITALY
Passive and Active Calibrators for Multifrequency and Multiangle X-SAR/SIR-C Image Radiometric and Geometric Corrections
I. OBJECTIVES
a) Prove that despite the considerable number of variables contributing to SIR-C/X-SAR image formation, the data can reveal system descriptors by studying the system response to "known targets" (either point-like or extended) within the scene.
II. APPROACH
a) Design and develop passive and active calibrators that will be used to instrument approximately 15 km2 of the test site. Instruments will be accurately located with respect to the geodetic network.
b) This instrumentation will be accurately calibrated, using an anecoic chamber and an antenna range. Prototypes of the instrumentation will be field-tested during the future airborne SAR campaigns in preparation for the SIR-C/X-SAR missions.
c) The multiangle capability and/or a slight shift between successive orbits will provide images of the test area under different illumination angles.
III. ANTICIPATED RESULTS
a) Development of a step-by-step research program focused on airborne campaigns to design, test, and operate a set of ad-hoc multifrequency instrumentation for SAR calibration and data validation.
b) Integration of the calibration data with raw SAR data for fine tuning of processor parameters.
c) Evaluation of the potential of SAR interferometry for topographic mapping, based on point targets of known radar cross-section (RCS), geographic coordinates, and phase behavior.
d) Improvement of the existing RCS databases.
C. N. E. T. Michel Normand CEMAGREF
U. V. S. Q. Didier Massonet CNES/TI
10-12 Avenue de l'Europe
78140 VEC12Y
FRANCE
Test of Roughness and Moisture Algorithms Using Multiparameter Space Borne SAR and Application to Surface Hydrology
I. OBJECTIVES
a) Evaluate the usefulness of radar-derived parameters in surface hydrology.
b) Demonstrate the usefulness of the squint mode in the case of bare soil observations.
c) Compare various roughness/moisture algorithms in a real space imaging mode.
II. APPROACH
a) The proposal is based on comparison between radar observation and well documented ground truth within a watershed.
b) The radar data will be compared to ground data using existing surface/wave interaction models.
c) An airborne dual frequency (C and X) multipolarization scatterometer will be used to calibrate radar data and to complete the data set (in view angle).
III. ANTICIPATED RESULTS
a) Calibration of the Shuttle radars over distributed targets
b) Test of multi-incidence angle algorithms using squint mode SAR
c) Test of roughness/moisture algorithms
d) Evaluation of the usefulness of SAR in surface hydrology including surface runoff parameters, rain discharge relationships, flood forecasting, improvement of hydrological modeling.
Laboratory for Oceans Edwin T. Engmann USDA/Agr. Res. Center
Code 675 Manfred Owe GSFC
Goddard Space Flight Center James C. Shiue GSFC
Greenbelt, MD 20771
SIR-C Measurements of Soil Moisture, Vegetation and Surface Roughness, and their Hydrological Application
I. OBJECTIVES
a) Analysis of SIR-C/X-SAR response to soil moisture, vegetation and surface roughness and development of an algorithm to retrieve these parameters.
b) Combination of the visible and near-infrared data and the SIR-C/X-SAR data to improve the range and accuracy of vegetation classification.
c) Testing of theoretical models for microwave propagation with SIR-C/X-SAR and microwave radiometric measurements over rough surfaces.
d) Evaluation of a water balance model using SIR-C/X-SAR derived soil moisture values and other ancillary data.
II. APPROACH
a) Selection of a test site which would provide a wide spectrum of soil moisture, vegetation and surface roughness for SIR-C/X-SAR observations.
b) Request of aircraft polarimeter and radiometer flights before and during the SIR-C/X-SAR mission.
c) Activities of the ground truth data collection, as well as other relevant satellite and ancillary data acquisitions.
d) Processing of data from SIR-C/X-SAR, satellite, and aircraft flights. Analysis of microwave signatures with respect to surface parameters leading to algorithm development for parameter retrieval. Evaluation of a generalized water balance model using the retrieved soil moisture and other ancillary data.
III. ANTICIPATED RESULTS
a) The relationship between surface parameters and imaging radar signatures will be established. An algorithm based on this relationship to retrieve the surface parameters will be developed.
b) Verify that an imaging radar system with multiple frequencies and polarizations is an efficient tool for vegetation classification. Assessment will be made of the classification scheme improvement when visible and near-infrared data are included.
c) Using SIR-C/X-SAR and ground measured roughness data, assess the validity of current theoretical models for microwave backscatter from rough surfaces.
d) Using the SIR-C/X-SAR retrieved soil moisture and other ancillary data, verify the validity and limitation of a generalized water balance model.
DLR Prof. Kubbauch Universitat Bonn
German Remote Sensing Data Center S. Mohan Space App. Center
D-82234 Oberpfaffenhofen
GERMANY
Information Extraction from Shuttle Radar Images for Forest Applications
I. OBJECTIVE
a) The experiment will attempt to extract all possible information from shuttle borne radar images (SAR) for areas with forest stands.
b) Use extracted information to evaluate/characterize forest parameters including differentiation between coniferous and deciduous forests, tree stand geometry, seasonal changes. Specific radar-tree interaction schemes including dependence of leaf/needle geometry and alignment to radar backscatter will also be investigated.
II. APPROACH
a) Forested areas to be studied in the experiment will comprise the range from non-forest/deforested areas to bushland areas, reforested areas and finally, small groves to large woodlands.
b) The experiment and the proposed data processing algorithms will utilize mainly the X-band SAR data in one polarization, but will also take advantage of the SIR-C L- and C-band data with different polarization and look-angles.
c) The experiment will use geocoded images to co-register the radar data with other geocoded satellite-borne images including multiband TM data and high resolution SPOT data. The strong dependence of radar data on topographic relief will make the incorporation of digital elevation models (DEM) necessary.
d) To obtain information for forest applications the principal backscatter mechanisms of microwaves with trees, trunks, leaves, and needles must be known. Three main parameters can be identified:
1. Radar parameters: These are wavelength, polarization and incidence angle. The SIR-C/X-SAR mission will vary all parameters, delivering a maximum flexibility to the investigators.
2. Target parameters: These can be further sub-divided in geometric parameters such as roughness, density, pattern, height, and dielectric property parameters which are mainly influenced by the moisture content of the canopy. Especially the tree/forest geometry could allow a classification of different species from SAR images.
3. Underlying soil parameters: Mainly the surface roughness and the dielectric properties of the soil which are governed by humidity.
III. ANTICIPATED RESULTS
a) Differentiation of forested and non-forested areas with an assessment of the accuracy of separation.
b) Information on the tree stand geometry, age classes of trees, and seasonal changes.
University of North Dakota Anthony England Johnson Space Center
Fargo, ND Minard Hall Escuela Pol. Nacl., Ecuador
Stanley Williams Arizona State University
SIR-C Radar Investigations of Volcanism and Tectonism in the Northern Andes
I. OBJECTIVE
a) Increase understanding of the volcano-tectonic history of the Northern Andes of Colombia and Ecuador by testing and extending the volcano-tectonic segmentation model proposed by Hall and Wood (1985).
b) Develop radar models for detecting and mapping pyroclastic and mudflow deposits at Ruiz and other dangerous volcanoes of the Northern Andes.
II. APPROACH
a) Use SIR-C/X-SAR images to examine areas identified by Hall and Wood as having anomalous volcano-tectonic characteristics; e.g., determine if young volcanoes uncertainly glimpsed in Landsat images of south-central Colombia exist; search for caldera (?) source of extensive, young ashflows in southern Ecuador; map tectonic details of surface area above apparent collision of adjacent subducted slabs.
b) For forested volcanic areas, develop statistical characterizations of terrain morphologies (canopy morphologies) to recognize and classify volcaniclastic terranes of various ages. For vegetation-free areas, develop theoretical scattering models based on the statistical roughness characteristics of volcaniclastic terranes of different ages. These models will be tested against the multi-wavelength, quad-polarized radar signatures of the volcanic terranes at Ruiz volcano (eruptions in 1986, 1945, 1595), Doña Juana (1897), Guagua Pichincha (1660), Cotopaxi (1877), and Tungurahua (1916).
III. ANTICIPATED RESULTS
a) Greatly improve geologic knowledge of poorly mapped, frequently cloud-covered, volcanically active arc.
b) Discover currently unknown source structure for large, 14,000 year old ashflow deposit in southern Ecuador.
c) Increase understanding of a seismically unusal subduction setting.
d) Develop an optimal interpretation of radar data for detection and mapping of pyroclastic/lahar deposits in tropical environments.
e) Improve understanding of distribution and character of poorly mapped deposits at Ruiz and other explosive volcanoes in the area.
f) Recognize prehistoric Ruiz-like deposits around other North Andean volcanoes and hence increase awareness of volcanic hazards.
Mail Stop 300-235 Charles Elachi Jet Propulsion Laboratory
Jet Propulsion Laboratory Philip Hartl University of Stuttgart
4800 Oak Grove Drive Jakob van Zyl Jet Propulsion Laboratory
Pasadena, CA 91109
Multifrequency Imaging Radar Polarimetry: Geophysical Factors from Penetration Phenomena
I. OBJECTIVES
a) To model, experimental]y characterize, and verify penetration phenomena in hyperarid and vegetated regions using the SIR-C/X-SAR multiparameter radar system and groundbased receivers.
b) To invert measured radar backscatter as a function of frequency and polarization in terms of geophysical parameters of the surface, subsurface and vegetation canopy such as surface roughness, subsurface geomorphology, or tree height and density.
c) To display subsurface and within-canopy features in an image format, thus easing the interpretability of the results.
II. APPROACH
The approach we propose is utilization of multifrequency polarimetry to separate and characterize the radar return into surface and volume scattering components. Specifically, we will:
a) Model the backscatter from hyperarid and vegetated areas in terms of the geophysical parameters describing in particular subsurface and within-canopy structure and composition.
b) Collect SIR-C and supporting aircraft multifrequency polarimetric data.
c) Separate the measured return into surface and subsurface or within-canopy parts based on polarimetric behavior as a function of frequency.
d) Deploy ground receivers during the experiment to measure field strengths at both vertical and horizontal polarizations. These in situ measurements will constrain and confirm our theoretical models.
e) Invert the measured scattering characteristics in terms of the modeled geophysical parameters.
III. ANTICIPATED RESULTS
a) An increased understanding of penetration phenomena in scattering.
b) Identification of sources for backscatter in hyperarid subsurface imaging, and quantitative assessment of the relative contribution of canopy top, volume, and ground surface scattering components to the return signal from vegetation canopies.
c) Solutions for descriptive geophysical parameters in the