MODISL1DB 1.8 (Released June 4, 2012)
MODISL1DB is a MODIS Level-1 Direct Broadcast software package
capable of processing MODIS Aqua and Terra Level 0 data to Level 1A and
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:
- Updated to the l1bgen programs
- Processing scripts have been modified (now python scripts):
- modis_L1A.csh -> modis_L1A.py
- modis_GEO.csh -> modis_GEO.py
- modis_L1B.csh -> modis_L1B.py
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.
- Linux 64 bit
- Intel Macintosh OS X 10.6/10.7
Download and Installation
Before installing the MODISL1DB package, please read (and agree to) the
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
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
MODISL1DB, and follow the installation instructions.
MODISL1DB is command-line driven, with processing controlled by four main
wrapper scripts: modis_L1A.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
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
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: