SeaDAS 4.5 Release Notes (02/25/04)
-----------------------------------
This release provides, for the first time within SeaDAS, the ability
to process and display MODIS/Aqua data.  We plan to provide
the ability to process MODIS/Terra data in the near future.
But for now, SeaDAS 4.5 provides the capability to:

        - create a Geolocation file from MODIS Aqua Level 1A data
        - create a Level 1B file from MODIS Aqua Level 1A data
        - create a Level 2 file from MODIS Aqua Level 1B data

We also plan to provide the capability to produce various
MODIS Aqua Level 3 files in the near future.  This initial release
only supports RedHat Linux 7.3.  Support for RedHat 7.2 and 7.1
will be forthcoming shortly, followed by support for Solaris 2.8,
Solaris 2.7, and Irix 6.5.  We do not anticipate being able to
provide support for RedHat 8.0 or 9.0, but we are planning on
providing support for Fedora 1.0 sometime within the next few
months.

The format of the Level 1A and Level 1B Aqua data is very
similar to the format of the data that is available from the
Goddard DAAC, with the exception that it does not have the
250m or 500m data which are being used currently primarily for
land studies.  Users can obtain the global Level 1A 1km data
from our Ocean Color website at http://oceancolor.gsfc.nasa.gov
through the Level 1 and 2 Browser link and through the Data
Subscription service.  There is also a link on this page for
the Oceans FTP site, where you can find ancillary MET/OZONE
files, attitude and ephemeris files, Aqua Level 3 SMI files,
and recent Aqua day and nighttime files.  Further detailed
information on the format of the various data files is described
at the link for "Overview of MODIS Processing with the Satellite
Data Processing System" available at:

        http://oceancolor.gsfc.nasa.gov/ocproducts.html.

Support for processing of additional Level-1 formats, including IMAPP
Direct Broadcast format, will be added in a future release and we
are going to work closely with the Direct Broadcast community and
software developers towards this goal.

The Geolocation and Level-1B processing software provided with this
release is the standard institutional code produced by SDST and MCST,
respectively. The Level-1B code has been slightly modified to ignore the
missing 250 and 500-meter data.  The Level-1B look-up table for the
reflective solar bands has also been modified in an effort to improve the
extrapolation of sensor calibration into the future.  This extrapolation is being
actively monitored by the MODIS Oceans Cal/Val team, and updates to the
Level-1B look-up table will be provided when necessary through periodic
updates that you will be notified of.

The Level-2 processing software for MODIS makes use of the same
multi-sensor code used for SeaWiFS, OCTS, MOS, and OSMI. A
description of the differences between this software and the code used in
the past to produce the GDAAC products is available here:

    http://oceancolor.gsfc.nasa.gov/DOCS/modis_processing_overview.pdf

A note about creating Geolocation files:
----------------------------------------
In order to successfully create a Geolocation file from a Level
1A file, you must have the proper Attitude and Ephemeris files
loaded onto your hard drive in the proper location.  The Attitude
and Ephemeris files should go under the $SEADAS/data/modisnpp/atteph
directory.  They should be further divided in subdirectories by year
and day.  There are two ways to get the Attitude and Ephemeris files.
The first way is through the Oceans FTP site, which is located at:

        oceans.gsfc.nasa.gov.

Navigate down through MODISA/ATTEPH, and then to the year and day
desired.  The Attitude files have the string "ATT" in them, and the
Ephemeris file has the string "EPH" in it.  There is only one Ephemeris
file per day at noon, and there are twelve attitude files per day,
one per two-hour period.  An Ephemeris file covers a 24-hour period
beginning with the day and time in the file name.  An Attitude file
covers a 2-hour period beginning with the day and time in the file
name.  Here is an example of a command that would help you to easily
download files for 2004 day 044:

        ncftpget -R oceans.gsfc.nasa.gov . MODISA/ATTEPH/2004/044

The second way to obtain the files is through the SeaDAS ftp site,
which provides them in compressed tar file format in 30-day chunks.
The files are in the same location as the SeaDAS software.  The format
for the filenames is seadas_modisaeYYYYDDDDDD.tar.gz.  The "modisae"
part of the filename stands for "MODIS Attitude Ephemeris".  The "YYYY"
is the 4-digit year.  The first three "DDD" stand for the beginning
julian day of the chunk, and the last three "DDD" stand for the ending
julian day for the chunk.  For example, seadas_modisae2004001030.tar.gz
contains all of the Aqua Attitude and Ephemeris files for Jan. 1
to Jan. 30, 2004(day 001 to 030).  There are different rules for
what attitude and ephemeris files are required depending on the
start time of the Level 1A input file, but those rules are handled
by the processing scripts.  For your purposes, it would probably be
best just to ensure that you have all of the attitude and ephemeris
files for the day of the file you are processing, plus for the day
before and the day after.  In order to properly install the attitude
and ephemeris files from these compressed tar files, download the
appropriate compressed tar file into your $SEADAS directory, then
use the following command(as an example) to put them into the
appropriate directory:

        gunzip -c seadas_modisae2004001030.tar.gz | tar xvf -

This will automatically put them in the correct location under the
$SEADAS/data/modisnpp/atteph directory.

A note about errors/bugs within SeaDAS 4.5:
-------------------------------------------
The addition of the MODIS Aqua processing and display capabilities
to SeaDAS has required a fair amount of effort.  We have completed
a significant amount of testing to try to bring you the most stable
and error-free software package possible.  However, we are a team
of only two developers, so we are unable to guarantee that you will
not find any errors or problems with the software.  We want to work
with the user community to find and resolve any problems that may
come up.  If you discover a bug or an error, or if you simply have
a suggestion that would make the software more useful, please let
us know.  We will evaluate and prioritize all problems and suggestions,
and try to provide you with the most expedient updates possible.
User support for bugs and general questions are handled through our
user support e-mail address:

        seadas@seadas.gsfc.nasa.gov

General announcements concerning SeaDAS are available both at our
main website:

        http://seadas.gsfc.nasa.gov

and also through the Ocean Color Forum website at:

        http://oceancolor.gsfc.nasa.gov:40000

We have also established a forum for SeaDAS questions at the same
location.  We hope that this might serve as a site for Frequently
Asked Questions.

The SeaDAS Development Group