Program Name: Bit Mapper
Program Description: This IDL program extracts bit flags from byte data arrays, and then plots them on a geolocated map with a user-defined color scheme. The specific codes are designed to extract MOD06 L2 QA bit flags and Cloud Mask (MOD06 or MOD35) bit flags, but can be modified to extract and visualize other bit flags. The program is separated into two codes, one which performs the extraction and one that visualizes the bit flags. The Extraction code (included are codes to extract the MOD06 L2 QA flags and the Cloud Mask (MOD06 or 35) flags) allows the user to extract the bit flags from the specified granule, and output the flags to individual SDSs inside a new HDF file. The visualization code reads in the bit flag SDSs from this new HDF file, and plots them on a geolocated map. The user can specify the color scheme to use for bit flag values and which flags are to be plotted. Individual or multiple granules can be plotted on a single map. This code can be modified to extract and visualize bit flags from other byte arrays.
Language and Environment Requirements: IDL
Limitations: The code was tested using IDL version 5.2, more recent versions of IDL have not been tested and results can not be guaranteed.
Installation Tips: Once the files are unzipped and untarred, examine the README.txt and PACKINGLIST text files for more details on installing and running the code.
Developer: Eric Moody (NASA GSFC)
Current Version: Version 1.0 (20 March 2001)
Note: Download file is zipped and tarred.
To Unzip use the command "gzip -d filename".
To UnTar use the command "tar -xvf filename".