This document contains descriptions of the contents of the data and browse 
collections, extracted from the PDS3 datinfo.txt and browinfo.txt files.


RGRAM and GEOM SUBDIRECTORIES.

For each SHARAD track there are two radargram data products: a 32-bit raw 
image and a geometry table file. 

The 32-bit raw image file (*RGRAM.IMG) contains the processed radargram 
image data (a 2-D slice through the surface and subsurface). The image 
collection and processing parameters are defined in the accompanying 
detached ASCII label file (*.LBL).  

The geometry table file (*GEOM.TAB) tabulates the important geographic, 
geometric, and phase-processing properties at each column of the radargram 
image. The table columns are defined in the accompanying detached ASCII 
label file (*.LBL).

The DATA files are named as follows:

S_YYYYYYZZ_RGRAM.IMG
S_YYYYYYZZ_GEOM.TAB, where

S             = Standard prefix for US-team SHARAD products
YYYYYY        = Orbit number, prefixed by zeroes to allow for 6-digit values
ZZ            = Observation number along the orbit track, prefixed by a zero 
                for values less than 10
RGRAM, GEOM   = Raw radargram image or geometry table data product 
                designation
.IMG, .TAB    = IMG or TAB file extension

The RGRAM and GEOM data subdirectories are further subdivided based on orbit 
number. For example, the RGRAM S_0015XX folder contains all the raw 
radargram images from orbit 1500 through 1599. 

For more information about the format and content of the data products, see
the RADARGRAM_DS.CAT, which can be found in the CATALOG directory.


TIFF AND THM SUBDIRECTORIES.

Within these subdirectories, the browse products are organized in a 
structure that parallels that of the DATA directory. Each browse product 
corresponds to a raw radargram image product.

There are two types of browse data products: a full-resolution TIFF and a 
reduced-resolution JPEG version of the 32-bit radargram data.

The full-resolution 8-bit TIFF (*TIFF.TIF) exhibits fixed scaling of 
0.137 dB in backscatter strength per DN value from 0-255. The spacing along 
track is always 128 pixels per degree, based on the equatorial radius. The 
number of rows is always 3600. The file size and source 32-bit data are 
defined in the accompanying detached ASCII label file.

The reduced-resolution JPEG (*THM.JPG) is produced for easy downloading or
viewing of a smaller file and should not be used for quantitative analyses. 
The image dimensions and source 32-bit data are defined in the accompanying 
detached ASCII label file. 

The BROWSE files are named as follows:

S_YYYYYYZZ_THM.JPG
S_YYYYYYZZ_TIFF.TIF, where

S          = Standard prefix for US-team SHARAD products
YYYYYY     = Orbit number, prefixed by zeroes to allow for 6-digit values
ZZ         = Observation number along the orbit track, prefixed by a zero for 
             values less than 10
THM, TIFF  = Thumbnail jpeg or Full-resolution tiff browse product designation
.JPG, .TIF = JPEG or TIFF file extension