UNIX
Bruce Chapman, JPL
bruce.chapman@jpl.nasa.gov
(For information about obtaining JPL developed software, please contact Ellen O'Leary at ellen.oleary@jpl.nasa.gov)
The current version of the software is found on tape version 2.0 (March 24, 1995) and contains : CEOS_READER version 2.0, dcomp version 3.0, and cvert version 2.0).
This guide will follow a cookbook type approach to loading software to disk, compiling the code, loading the data to disk, creating the ASCII CEOS header files, reading the ASCII CEOS header files for the decompression software, multilooking the data, synthesizing a byte image, and converting between SIR-C and AIRSAR formats. The examples given are for a unix system, in particular a DEC alpha computer running OSF/1, but it should be very similar for any unix workstation. On a VAX/VMS system, there are more significant differences, but they are described in the manuals for the software.
At the end of the software demonstration description, there is a printout of all the ASCII files that were created.
The steps that are taken by each user depend on what they want to do with the data. DO NOT BLINDLY DO EVERYTHING IN THIS GUIDE, THINK ABOUT WHAT PRODUCT YOU WANT AT THE END (A MULTILOOKED IMAGE, A BYTE IMAGE, AN AIRSAR FORMAT IMAGE, ETC.)
Loading ceos_reader and decompression software, and SIR-C/AIRSAR conversion software
1. make executables
a. mkdir a directory for software, cd to directory
b. tar -xvf /dev/rmt0h (rmt0h is the tape device name)
c. this creates three subdirectories directories : ceos_reader, cvert, and dcomp
d. cd to each directory and make the executables (C and fortran77).
1. in the ceos_reader directory, the command is
> make -f ceos_reader.make
2. the user may have to modify this make file if acc (ansi C) is not defined, or define acc.
3. in the cvert and dcomp directory, the command is
> make
2. add directory of software executables to path, or create aliases.
1. If you have the program Macsigma0 (which currently is only available on a Macintosh computer) , then you may want to convert the SIR-C format data to AIRSAR format.
a. run the CEOS_READER program to copy the data from tape to disk, and create ASCII CEOS headers.
b. read the ASC II header files with dcomp or cvert.
c. if you have SLC data, then first multilook the data ( I recommend multilooking the data so that it is approximately in the ground range projection). Then, convert it to AIRSAR CM format. If you have MLC data, you may still want to multilook the data as the AIRSAR format is limited to 1024 samples. Then, convert it to the AIRSAR CM format.
d. copy the data to your macintosh computer
e. Macsigma0 displays and performs simple analysis of the data with an easy user interface. Macsigma0 is on the SIR-C education pre-flight CD-ROM.
2. If you have IDL (interactive display language from RSI, Inc.) :
a. run the CEOS_READER program to copy the data from tape to disk, and create ASCII CEOS headers.
b. run utility programs to read the headers and synthesize byte images (with image display).
c. or run Raven, which displays and performs simple analysis of the data with an easy user interface.
d. If you have X-SAR data, and want to co-register it to the SIR-C data, then run SIRC-REG.
3. If you have only simple display software
a. run the CEOS_READER program to copy the data from tape to disk, and create ASCII CEOS headers.
b. read the ASC II header files with dcomp or cvert.
c. run dcomp to multilook the data (if you want to average the data down.
d. run dcomp to synthesize a "vicar" labeled byte image. A byte image with a vicar label may be displayed with the public domain xv software (version 2.x). Or, some software may input "raw" byte images and display them.
4. Some commercial software vendors support or will support the SIR-C CEOS format, such as PCI software from PCI, Envi from IDL, or ARC/info from ESRI.
5. This guide does not provide information about using interferometry data.
6. Refer to the software manuals for using IDL programs such as Raven.
1. run ceos_reader software to copy a data set to disk
a. make a directory on a disk with plenty of disk space for the data
b. run ceos_reader
> ceos_reader tape=/dev/nrmt0h
1 - continue
1 - product menu
3 - copy
return
return
return
0
c. this command copies the ceos header files and the image file to disk
d. if there is more than one ceos data set on the tape, run the ceos_reader again without rewinding.
2. run ceos_reader create ASCII header files
a. run ceos_reader
> ceos_reader disk=pr10542_img_ceos
1 - continue
2 - file
3 - decode/save
return
return
return
0
b. similarly execute (and proceed as before)
> ceos_reader disk=pr10542_ldr_ceos
> ceos_reader disk=pr10542_tlr_ceos
c. this creates the ASCII CEOS header files
read ascii headers for decompression
1. run cvert to get .cbh file
a. run cvert
> cvert
1 - read/create headers
1 - create common block header file
10542 - enter pr number
1 - DEC computer
10 - exit
b. can do the same thing with create_in program
c. creates a simple file with 6 numbers that are necessary for decompression
d. name of file created is pr10542.cbh
e. if there is another CEOS file (i.e. a C-band image that is coregistered with this L-band image (pr10543) , then the C-band data will have an identical .cbh file)
f. cvert program requires more memory than create_in program.
2. run cvert to get .info file
a. run cvert
> cvert
1 - read/create headers
2 - create read headers
10542 - enter pr number
10 - exit
b. can do the same thing with info program
c. for information about the scene only
d. some values required for SIR-C to AIRSAR conversion
e. supplies amount of multilooking necessary to convert to approximate ground range
f. name of file created is pr10542.info
g. cvert program requires more memory than create_in program.
3. if the ASCII files are unavailable, then select option 4, and manually determine the common block header file.
multilook the data
1. run cvert program on data file to convert to ground range (SLC to MLC)
a. multilook the data to approximately ground range projection, as SLC data is in the slant range projection :
> cvert
9- multilook
pr10542.cbh - common block header file name
pr10542_img_ceos_image - SLC input image file name
pr10542.ml - output MLC image file name
10 - multilooking in azimuth direction (from pr10542.info file)
2 - multilooking in range direction (from pr10542.info file)
pr10542ml.cbh - output common block header file
b. depending on the computer, this may take awhile. On a DEC alpha, 5 minutes, on a SUN sparc 2, up to an hour.
c. output MLC file (pr10542.ml) will be approximately in the ground range projection. pixel size (from pr10542.info file) will be 42 meters, and will be 20 looks.
d. cvert program, option 9, will also multilook the data. cvert requires more memory than multilook.
e. CEOS header file is not updated.
f. use cvert version of multilooking rather than multilook program for SLC data.
make a byte image
6. run byte_image to create byte image
a. run byte image program
> byte_image
pr10542ml.cbh - common block header file name for multilooked file
pr10542.ml - multilook data file name
pr10542.hh - output byte image file name
1 - select just a subset of the image to make into a byte image
1 - first line
1024 - number of lines
1 - first sample
670 - number of samples
0 - transmit ellipticity
0 - transmit orientation
0 - receive ellipticity
0 - receive orientation
0 - use amplitude rather than power
0 - use relative scale factor
1.0 - relative scale factor
b. HH is the polarization of the output image
c. different scale factors will emphasize either higher or lower sigma0 values
d. output image is not in units of sigma0
e. program types the dimensions of the output file
f. easy to display with a variety of software
g. for dual and single pol data, will prompt for polarization for output.
h. number of samples (in bytes) reduced to 668 on a DEC computer (to be divisible by 4)
i. for quad pol data, any polarization may be synthesized.
convert MLC file to AIRSAR CM format
1. run cvert
a. type out pr10542.info file to reference
b. do not need to read SIR-C ASCII header file - we are now working with a MLC data file, and the .cbh file already exists
> cvert
pr10542ml.chb - common block header file for MLC data
pr10542.ml - input MLC data file name
1 - first SIR-C azimuth line
1 - first SIR-C range sample
670 - number of SIR-C range samples
ground - data in ground range projection
43 - range pixel spacing (after multilooking if any)
41 - azimuth pixel spacing (after multilooking if any)
264996 - near slant range (meters)
219337 - platform altitude (meters)
0 - target elevation (feet)
0 - drift angle (-yaw of radar)
149 - track angle of radar platform (degrees)
0 - roll angle of radar platform (degrees)
L - frequence band
10542L - less thand 6 character string identifying scene
cm10542L.dat - output AIRSAR data file name
cm10542L.cbh - output common block header file name
10 - exit
c. range and azimuth pixel spacings may be found in .info file. Range spacing is not the same as original pixel spacing x number of looks in range direction, due to approximate ground range conversion.
d. AIRSAR data is 'cornerturned' from SIR-C data.
e. assumes that user wants 1024 azimuth lines converted, as that is AIRSAR standard.
f. .info file contains most of these parameters that are requested.
g. any output names may be specified. any 6 character string may be input.
h. requires a lot of RAM memory, because of cornerturn
2. user may use byte_image program to create a byte image of an AIRSAR image.
convert AIRSAR CM image to SIR-C MLC
1. convert to SIR-C format with cvert
a. common block header file already exists. Run cvert
> cvert
cm10542l.cbh - AIRSAR cm common block header file
cmf10542l.dat - AIRSAR CM data file
pr10542.cm - output MLC image file name
pr10542cm.cbh - output common block header file name
10 - exit
b. CEOS headers are not updated or created
c. if common block header file must be created from an original header file, run cvert
> cvert
1 - read/create headers
3 - read AIRSAR header
cm10542l.dat - input AIRSAR data file
cm10542l.cbh.1
1 - DEC computer
1 - CM file
10 - exit