PDS_VERSION_ID        = PDS3
RECORD_TYPE           = STREAM

OBJECT                = TEXT
   PUBLICATION_DATE    = 2021-10-01
   NOTE                = "Description of contents of DATA directory."
END_OBJECT            = TEXT
END

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.