The images are gray scale images in which the brightness of the image corresponds to the amount of radar energy reflected back to the radar.
There are five items on the CD-ROM desktops - a "DATA" folder, a "DOCS" folder, a "README.UNX" file (for UNIX computers), a "README.PC" file (for PC and Mac computers), and a "1STPAGE.HTM" file. (You may also see some other auxiliary files.)
| The README is a short description of the CD-ROM in a text file, and "1STPAGE.HTM" is the first page of the html documentation. |
|
 |
The "DATA" folder contains all the GIF images and binary data. |
| The "DOCS" folder contains the html documentation. |  |
The data are in two data formats : 1) 15 arcsec (445-465 meter) (pixel spacing) GIF images; 2) 3 arcsec (89-93 meter) (pixel spacing) raw 8 bit images. The pixel spacing (in meters) of each mosaic tile depends upon the Latitude and on the number of arcseconds per pixel for the tile. In general, the pixel spacing is close to 15 arcseconds (Latitude and Longitude) for the Lowres GIF images, and about 3 arcseconds for the raw 8 bit images.
The GIF images may be found either by clicking on the clickable map, or by clicking on an entry in the table of mosaic tiles.
You can find out if a location has been imaged, and, if so, which cd-rom it is on, using this web site.
The 8 bit raw images may be found in the "DATA" folder in the "BINARIES" subdirectory. These files will have the name ###.dat, where ### is the three digit tile number. The GIF images may also be found in the "DATA" folder in the "LOWRES" subdirectory.