AVIRIS DATA FACILITY
92qlook directory
See the top level
README.htm file for ordering and image viewing information.
See the announcements
page for a discussion on the future direction of the image format.
Please ftp a copy of the 92index.ql file from the docs directory, or use the file INDEX in the 92qlook directory. They are the same file. If you're using the WWW, then you can access the index via the INDEX.htm file in 92qlook or the 92index.htm file in docs/html. The file you are currently reading is both docs/html/92readme.htm and 92qlook/README.htm.
The index files list all the 1992 AVIRIS quicklook images based on flight and run. In addition the 1) number of lines, 2) site name, 3) acquisition time, and 4) the starting stopping coordinates and times of the data run are given.
Runs that have more than six scenes (more than ~3150 lines, depending on the length of the precal data) will have more than one quicklook, for we put at most six scenes in one image file. The naming convention is FFFFFFFRRSS.aql, where the F's are the flight number, the R's the run number, and the S's the starting scene number (which will be 01, 07, 13, etc.) For example, the quicklook for: 1) Flight 920908A, 2) run 4, and 3) starting scene 1 will have the file name 920908A0401.aql.
Once you have identified the quicklooks of interest please ftp them to your local computer. Use binary (sometimes called "image" in some ftp implementataions) format, as opposed to ascii.
These online quicklooks are stored as 2 by 2 line-sample averaged images of up to 6 consecutive AVIRIS scenes of channel 35 data. Each file is exactly 307 samples by 1536 lines. The images are stored a flat binary byte data.
Each original 512 line AVIRIS scene has been independently stretched, so the scene boundaries are generally apparent. Furthermore, there may be uniform black (or white) and gray areas. Since each scene is stretched independently, a scene with less than 512 lines (the length of a scene, before averaging) will have black (or white) until the end of the scene. The scenes following this partial scene do not exist, and even gray data is substituted so all files are the same size.
Between each scene is a black and white dashed line, and scene 1 is at the top of the image.
Whether the areas are black or white depends on when the data was processed. Unlike the 93 qlooks, which were processed from our full size quicklook products, and thus uniform in data representation, the 92 qlooks were made from our browse images, which are already reduced in size. Halfway through the 92 season we changed our minds as to how the areas of no data in a scene would be represented in the browse images. The data before 8/25/92 uses black, while that from 8/25/92 on uses white. It follows from this that the bad and missing lines in the data are the same color as the uniform black/white areas.
SOME CAVEATS:
There may be some files missing, but few. If a file you need is
missing, contact av_tech as outlined below.
Yes, there are some '93 files here, but that's because the 1992 season is considered to go until the beginning of the '93 season (March).
To pub directory documentation page
To 92qlook directory listing
Contact information
Mail to:
AVIRIS Data Facility
M/S 169-315
Jet Propulsion Laboratory
4800 Oak Grove Dr.
Pasadena, California 91109
(818) 354-5366