F. A Kruse

Analytical Imaging and Geophysics LLC

4450 Arapahoe Ave, Suite 100

Boulder, Colorado 80303

9 April 1997

This is a final summary report requested by Jeff Plaut, SIR-C Experiment Scientist to help document the accomplishments of the SIR-C/X-SAR Program. It describes the research on JPL Contract 958456 at the University of Colorado and JPL Contract 960248 at Analytical Imaging and Geophysics LLC, both titled "Comparative Lithological Mapping using Multipolarization, Multfrequency Imaging Radar and Multispectral Optical Remote Sensing" This report summarizes research results over the course of the funded SIR-C Experiment by the Principal Investigator (Kruse).

The main objectives of this research were:

1. To 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

1. To use variation in radar backscatter as a function of wavelength and polarization to characterize the geometry, and indirectly the composition of rock units.

1. To compare radar characterization with visible/infrared characterization of surface materials

1. To map the character and distribution of lithological variation with SIR-C/X-SAR by preparing detailed lithologic maps of selected sites.

University of Colorado Research

From inception of the SIR-C/X-SAR project in 1988 until 31 March 1995, this research was supported under JPL Contract 958456 with the University of Colorado.

The research at CU concentrated on compiling and analyzing optical and SAR data sets, learning better how to use SAR data for geologic mapping, and establishing the framework for geologic analysis using SIR-C. This included much of the preparatory work for SIR-C, including acquiring NASA Airborne data and preparing multiple optical and SAR data sets for analysis and use with the SIR-C data. Data analyzed included Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), Thermal Infrared Multispectral Scanner (TIMS), and JPL airborne SAR (AIRSAR). Small sample data sets for a site near the northern Grapevine Mountains, California/Nevada, were georeferenced and combined analysis was performed. The AVIRIS and TIMS data provided detailed lithologic information in the form of mineral maps and color composite images. The AIRSAR data were processed to color composite images and a small perturbation model was also used to extract surface roughness values from the data. Several sessions of field mapping and verification were conducted. Algorithms were developed that could be applied to the SIR-C data. Preliminary processing of SRL-1 data from the Death Valley Supersite included initial registration of X-SAR to the fully polarimetric SIR-C data, generation of gray scale and three frequency color composite images, and trial inversion of the SIR-C data to surface roughness. Two field checks of SIR-C processing results were conducted in January and March 1995. Significant results are summarized in section 2 below.

Research at Analytical Imaging and Geophysics (AIG)

Effective 10 April 1995, this SIR-C research was transferred to Analytical Imaging and Geophysics LLC (AIG), Boulder, Colorado, under JPL Contract 960248. Research at AIG from 10 April 1995 to March 1997 concentrated on utilizing the SIR-C and X-SAR data from SRL-1 and SRL-2 for geologic mapping. Combined optical remote sensing data sets including Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), Thermal Infrared Multispectral Scanner (TIMS), SPOT, and Landsat TM were used with SIR-C/X-SAR to develop an improved understanding of the current geomorphic expression of rock surfaces by determining the relationship between surface morphology, lithological variability, weathering, soil development, and vegetation distribution. This research demonstrated that combined optical/SAR data sets provide an efficient means of compiling both regional and detailed lithologic information for geologic mapping

Selected research accomplishments include:

• Production of SIR-C image-maps of selected sites world-wide, including the Death Valley Supersite; Bighorn Basin, Wyoming; Sonora, Mexico; and Palm Valley, Australia as the basis for detailed lithologic mapping and field investigations. Synthesis of individual frequency and polarization images for SIR-C data, interactive viewing and analysis of individual detected images and color composites, and generation of hard-copy images for visual analysis. A small perturbation model was used to calculate the geophysical parameters "RMS surface roughness" and "Fractal Dimension" for selected sites at the Death Valley supersite. SIR-C and X-SAR data were co-registered for multifrequency studies and map-referenced along with SPOT, TM, TIMS, and AVIRIS data (See Figure 1 and digital file "sircomb.jpg" (~1Mb). The combined data sets were used for integrated analysis at selected sites. Field reconnaissance and mapping were conducted at the Death Valley, Bighorn Basin, and Sonora Mexico sites.

• Survey data from both the SLR-1 and SRL-2, CD-ROM sets were used to construct two mosaics covering the Death Valley Supersite and the Bighorn Basin, Wyoming site. The purpose of these mosaics was to provide a regional overview of the sites as an aid to structural interpretation, and to assist in selection, processing, and archiving of SIR-C/X-SAR data sets for precision processing. A precision SIR-C multifrequency, multipolarization digital mosaic was also produced for Death Valley National Park for detailed integrated analysis (See Figure 2 and digital file "dvnpmap.jpg" (~12Mb)).

• Several scenes of 1994 AVIRIS data were processed, analyzed, and map-registered to produce thematic image maps for comparison to SIR-C results (See Figure 1). 1995 AVIRIS data for a northern Death Valley site were also calibrated to reflectance using the ATREM atmospheric model and mineral maps were made for integrated analysis with Landsat TM and SIR-C/X-SAR

SIGNIFICANT RESULTS

• Successful use of combined optical/SAR data to provide new insights for geologic mapping, particularly of alluvial materials. Mapping of selected locations within the Death Valley SIR-C Supersite, Bighorn Basin Wyoming, Sonora Mexico, and Palm Valley Australia.

• Extraction of quantitative surface roughness using both AIRSAR and SIR-C to establish that under correct conditions (low topographic relief, composition and weathering characteristics closely linked, little surface moisture, and minimal vegetation cover), close associations do exist between lithology and fan roughness (eg: hydrothermal alteration of granitic material produced smoother fan that fan derived from unaltered granite Demonstrated, that in most cases, however, fan morphology and lithology are more closely related to tectonics and fan age rather than directly to bedrock composition.

• Training of graduate students in radar image processing at CSES, University of Colorado, and partial funding of 1 Ph. D. student for SIR-C studies at the Death Valley Supersite, 1 Ph. D. student for SIR-C studies in Sonora, Mexico, and 1 M.S. Student.

• Design, development, and delivery to JPL of the "Radar Analysis and Visualization Environment (RAVEN)" for analysis of polarimetric radar data. This software is now one of the standard software products released by JPL to the imaging radar community.

• Partial support of a subcontract to VEXCEL corporation to develop model-based techniques and software for geometric registration and rectification of AIRSAR and SIR-C/X-SAR using ephemeris data.

• Hosted SIR-C PI Geoffrey Taylor from the University of New South Wales, Sydney, Australia from July - November 1994, providing training and assistance for digital processing of AIRSAR and SIR-C data. Co-authored two papers based on cooperative research.

• Co-registration of SIR-C/X-SAR for selected sites world-wide. Efforts indicate that this is basically a non-issue other than the time and effort involved to perform the picking of ground control points. The two SAR datasets can be co-registered to acceptable error limits using standard image-to-image registration procedures available in many commercial remote sensing packages. It would be better if future multifrequency SAR missions would deliver inherently co-registered data sets to investigators.

• Registration of selected optical data sets including Landsat TM, SPOT, AVIRIS, and TIMS to the SIR-C data for selected sites. Standard image processing procedures can be successfully used to perform the registrations, however, SAR artifacts such as layover and foreshortening and radar shadow, cause difficulties. Registration for digital analysis requires significantly more ground control points and a rubber-sheeting warp method to achieve desired registration accuracy. Lack of adequate DEMs precluded terrain correction for most sites.

• Digital analysis and extraction of extended spectral signatures using "hyperspectral" analysis procedures was more effective in characterizing lithologic variability than multispectral processing techniques. A procedure typically used for analysis of imaging spectrometer data consisting of a Maximum Noise Fraction (MNF) rotation and "Pixel Purity Index (PPI)" determination, followed by visualization using n-Dimensional scatterplots was effective in defining lithologic endmembers for subsequent classification and mapping. These results were also useful in assigning physical basis to colors presented on the color composites generated using multispectral methods.

• In combination, these data sets provided complementary information to give an improved picture of the geology; TIMS for rock forming minerals, TM and/or AVIRIS for weathering products and some rock forming minerals (carbonate), and SAR for surface morphology. Combined SAR/Optical data sets provided the best way to fully analyze the geology using remote sensing data sets. The combination of these data sets provides powerful tools for lithologic mapping. The results of this research show that the combination of optical remote sensing and radar data provides distinct advantages for geologic mapping, particularly of alluvial materials. Insights obtained during this research are being used to develop models explaining the distribution of geologic materials with respect to their geomorphology and their relationships to bedrock lithology and tectonics. Research in these areas will continue after completion of the SIR-C project. The results of this continuing research are summarized further in proceedings papers and peer-reviewed manuscripts listed below

Refereed Journal Papers

Kierein-Young, K. S., 1996. Integration of optical and radar data to characterize mineralogy and morphology of surfaces in Death Valley, California: International Journal of Remote Sensing, (in press)

Taylor, G. R., Mah, A. H., Kruse, F. A., Kierein-Young, K. S., Hewson, R. D., and Bennett, B. A., 1996, The extraction of soil dielectric properties from AIRSAR data: International Journal of Remote Sensing. v. 17, no. 3, p. 501 - 512.

Taylor, G. R., Mah, A. H., Kruse, F. A., Kierein-Young, K.. S., Hewson, R. D., and Bennett, B. A., 1996, Characterization of saline soils using airborne Radar imagery: Remote Sensing of Environment, v. 57, p127 - 142.

Kruse, F. A., Lefkoff, A. B., and Dietz, J. B., 1993, Expert System-Based Mineral Mapping in northern Death Valley, California/Nevada using the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS): Remote Sensing of Environment, Special issue on AVIRIS, May-June 1993, v. 44, p. 309 - 336.

Kruse, F. A., and Lefkoff, A. B., 1993, Knowledge-based geologic mapping with imaging spectrometers: Remote Sensing Reviews, Special Issue on NASA Innovative Research Program (IRP) results, v. 8, p. 3 - 28.

Ph. D. DISSERTATIONS

Kierein-Young, K. S., 1995 (Geophysics), Integration of quantitative geophysical information from optical and radar remotely sensed data to characterize mineralogy and morphology of surfaces: Unpublished Ph. D. Dissertation, University of Colorado, Boulder, 220 p.

Martinez, S. A., 1997 (Geology), Geologic and remote sensing studies of the mineralization in the Arizpe area, Sonora, Mexico: Unpublished Ph. D. Dissertation, University of Colorado, Boulder, (in preparation).

M.S. THESIS

William Baugh, M.S., 1995, (Geology), Quantitative geochemical mapping of ammonium minerals using field and airborne spectrometers, Cedar Mountains, Esmeralda County, Nevada, Unpublished Master's Thesis, University of Colorado, Boulder.

PROCEEDINGS PAPERS

Kruse, F. A., 1996, Geologic Mapping Using Combined Analysis of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and SIR-C/X-SAR Data: in Proceedings, International Symposium on Optical Science, Engineering, and Instrumentation, SPIE Proceedings, v. 2819, p. 24 - 35.

Kruse, F. A., 1996, Geologic mapping using combined optical remote sensing and SIR-C/X-SAR data: in proceedings, 11th Thematic Conference, Applied Geologic Remote Sensing, 27 - 29 February, 1996, Environmental Research Institute of Michigan (ERIM), Ann Arbor, MI, p. II-142 - II-148.

Kruse, F. A., 1995, Mapping spectral variability of geologic targets using Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data and a combined spectral feature/unmixing approach: in Proceedings, AeroSense'95, SPIE, 17-21 April 1995, Orlando, Florida.

Kruse, F. A., 1993, Geologic mapping using integrated AIRSAR, AVIRIS, and TIMS data: in Summaries of the 4th JPL Airborne Geoscience Workshop, Washington, D. C., JPL Publication 93-26, v. 3., p. 29 - 32.

Curlander, J., Leberl, F., and Kruse, F. A., 1992, Geometric Ortho-Rectification and Generation of s-zero Image Products from Multiple Incidence Synthetic Aperture Radar Images: in Proceedings, IGARSS'92, 26-29 May, 1992, Houston, TX, IEEE Catalog Number 92CH3041-1, V. 1, p. 111-113.

Kierein-Young, K. S., Kruse, F. A., and Lefkoff, A. B., 1992, Quantitative analysis of surface characteristics and morphology in Death Valley, California using AIRSAR data: in Proceedings, IGARSS'92, 26-29 May, 1992, Houston, TX, IEEE Catalog Number 92CH3041-1, V. 1, p. 392 - 394.

Kruse, F. A., 1992, Geologic Remote Sensing - New Technology, New Information: in Proceedings, IGARSS'92, 26-29 May, 1992, Houston, Tx, IEEE Catalog Number 92CH3041-1, V. 1, p. 625 - 627.

Kierein-Young, K. S., and Kruse, F. A., 1992, Extraction of Quantitative Surface Characteristics from AIRSAR Data for Death Valley, California: In Summaries of the Third Annual JPL Airborne Geoscience Workshop, AIRSAR Workshop, JPL Publication 92-14, V. 3, p. 46 - 48.

Kierein-Young, K. S., Lefkoff, A. B., and Kruse, F. A., 1992, Radar Analysis and Visualization Environment (RAVEN): Software for Polarimetric Radar Analysis: In Summaries of the Third Annual JPL Airborne Geoscience Workshop, AIRSAR Workshop, JPL Publication 92-14, V. 3, p. 78 - 80.

Kruse, F. A., Dietz J. B., and Kierein-Young, K. S., 1991, (Extended Abst.), Geologic Mapping in Death Valley, California/Nevada Using NASA/JPL Airborne Systems (AVIRIS, TIMS, and AIRSAR): In Proceedings of the 3rd Airborne Synthetic Aperture Radar (AIRSAR) workshop, 23 - 24 May 1991, JPL Publication 91-30, p. 126-127.

Kruse, F. A., and Dietz, J. B., 1991, Integration of diverse remote sensing data sets for geologic mapping and resource exploration: SPIE Symposium on Remote Sensing for Geology and Geophysics, 1-5 April 1991, Orlando, Florida, v. 1492, p. 326-337.

Kruse, F. A., and Dietz, J. B., 1991, Integration of visible- through microwave-range multispectral image data sets for geologic mapping: in Proceedings of the Cinquième Colloque International, Mesures Physiques et Signatures En Télédétection, 14 - 18 January 1991, Courchevel, France, European Space Agency, esa SP-319, v. 2, p. 481-486.

Kruse, F. A., and Dietz, J. B., 1991, Integration of optical and microwave images for geologic mapping and resource exploration: in Proceedings, International Symposium on Remote Sensing of Environment, Thematic Conference on Remote Sensing for Exploration Geology, 8th, 29 April - 2 May 1991, Denver, Colorado, Environmental Research Institute of Michigan, Ann Arbor, p. 535-548.

Kierein-Young, K. S., and Kruse, F. A., 1991, Quantitative investigations of geologic surfaces utilizing Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and Polarimetric Radar (AIRSAR) data for Death Valley, California: in Proceedings, International Symposium on Remote Sensing of Environment, Thematic Conference on Remote Sensing for Exploration Geology, 8th, 29 April - 2 May 1991, Denver, Colorado, Environmental Research Institute of Michigan, Ann Arbor, p. 495-506.

IN-HOUSE REPORTS

Kruse, F. A., 1995, Final Report - JPL Contract 958456, Center for the Study of Earth from Space (CSES), University of Colorado, Boulder, 43 p.

Lefkoff, A. B., Kruse, F. A., and Kierein-Young, K. S., 1993, Radar Analysis and Visualization Environment (RAVEN User's Guide, Version 1.0 (Prototype), Center for the Study of Earth from Space (CSES), 20 p.

TRADE JOURNALS

Kruse, F. A., 1992, The analysis of scientific data from NASA airborne systems: Scientific Computing & Automation, June 1992, Elsevier, p. 15-22.

Figure 1 on following page: Combined data set for portion of Death Valley Supersite (northern Death Valley). Images show information content for various sensors. See also digital file sircomb.jpg (~1Mb).

• SPOT Panchromatic - High spatial resolution and surface albedo mapping.
• Landsat TM Ratios - General mineral mapping
• TIMS - Silica Mapping (Red is high silica)
• AVIRIS - Mineral mapping (the brightness of each color indicates mineral abundance)
• SIR-C multipolarization - Surface roughness and morphology differences
• SIR-C/X-SAR multifrequency - Surface roughness and morphology differences

Figure 1 here

Figure 2 on following page: SIR-C Death Valley and Vicinity Map-Sheet Mosaic of L-HH, L-HV, C-HV (RGB) in UTM Projection. Digital image file is "dvnpmap.jpg" (~12Mb).