SeaDASMODISL1DB is a MODIS Level-1 Direct Broadcast software package capable of processing MODIS Aqua and Terra Level 0 data to Level 1A and Level 1B.
This software is a culmination of various efforts made by the MODIS Science and Calibration Teams, including the latest processing source codes from the MODIS Science Data Support Team (SDST), the MODIS Characterization Support Team (MCST), and the Ocean Biology Processing Group (OBPG). Thanks also goes out to SSEC for continued support.
Processing MODIS data with MODISL1DB will result in identical products to those produced by the OBPG if the same calibration LUTs are used.
Notable changes in this release are:
Processing scripts have been converted to Python:
For more details see the Version History.
The main MODISL1DB user support medium is the MODIS Direct Broadcast Support Forum (one of the Ocean Color Forums). If you would like to contact us directly, please feel free to send questions or comments to seadas at seadas.gsfc.nasa.gov.
Before installing the MODISL1DB package, please read (and agree to) the SeaDAS Software Distribution Policy.
Please be aware that if the SeaDAS software package is already installed on your computer, you will already have full access to ALL of the functionality of MODISL1DB. If you do decide to also install MODISL1DB, SeaDAS and MODISL1DB should NOT both be enabled at the same time. To disable SeaDAS, simply comment-out any lines in your shell initialization file that set up the SeaDAS environment.
MODISL1DB can be downloaded and installed using the online installation page. The online installer will do everything for you, including downloading files, installing the software, and setting up your UNIX environment for MODISL1DB. Or, you can manually download MODISL1DB, and follow the installation instructions.
MODISL1DB is command-line driven, with processing controlled by four main wrapper scripts: modis_L1A.py, modis_L1A_extract.py, modis_GEO.py, and modis_L1B.py. A utility script (update_luts.py is also included to automate updating of calibration LUTs and utcpole.dat/leapsec.dat. It is suggested this script be set up as a cron job, though it can also be run manually. All MODISL1DB scripts reside in the ‘run/scripts’ directory. For usage instructions please consult each script’s associated README file.
The MODISL1DB benchmark script provided is now the same one used for SeaDAS benchmarks. The script is now called seadas_benchmark.bash and is available along with a MODIS Aqua Level-0 5 minute granule from our ftp site in the seadas_benchmarks.tar.gz file. When this script is executed, if a MODISL1DB environment is detected the script will simply process the Level-0 file to Level-1B and report the processing times. The SeaDAS Benchmarks Table lists processing times from various platforms for comparison to your computer’s performance. If you perform the benchmark, please email results along with your detailed system specs to seadas at seadas.gsfc.nasa.gov for inclusion in the table.
Source code is not distributed with the MODISL1DB software package. However, the complete source code and build environment for all MODISL1DB binaries is available within the Sea, earth, atmosphere Data Analysis System (SeaDAS)software package.
To build custom MODISL1DB binaries, users can install SeaDAS and then rebuild any of the MODISL1DB binaries within their SeaDAS environment. These custom binaries can then be substituted directly into an existing MODISL1DB installation. Or, if the processing component of SeaDAS is installed (distributed in the file seadas_processing.tar.gz), the following SeaDAS script can be run to create a complete MODISL1DB package (created in $SEADAS/modisl1db/) containing the new custom binaries:
$SEADAS/config/modisl1db/modisl1db_dist.csh
