The Earth Observer

March/April 1996, Vol.8, No.2

Science Working Group for the AM Platform (SWAMP) meeting

--Francesco Bordi (fbordi@pop400.gsfc.nasa.gov), NASA Goddard Space Flight

The Science Working Group for the AM Platform (SWAMP) met at the Lockheed Martin Astro Space facility in Valley Forge, Pennsylvania, on March 21 and 22, 1996. There was full attendance by all the EOS AM-1 Team leaders, by most of the software leads, and by several EOS AM-1 Project and ESDIS staff members.

Welcome and Project Status

After a brief welcome speech by Mike Kavka, the EOS AM-1 Project Manager at Lockheed Martin, Chris Scolese discussed the status of the Project: CERES has been integrated onto the TRMM spacecraft; all AM-1 instruments are in fabrication; the spacecraft flight components are in testing; and the Project is working on a three-month advance on spacecraft delivery.

Digital Elevation Model (DEM)

Martha Maiden (NASA Headquarters) is funding the DEM development and Thomas Logan (JPL) will oversee the work. A design study has been initiated and an implementation plan will be out soon. Specialists from JPL and EDC will lead the technical work and the assembly of the DEMs, while ESDIS will arrange for the toolkits to allow teams to access the data. The parties will keep the SWAMP informed of their progress and of any options that may arise.

Land-Sea Masks

Robert Wolfe discussed the need for land-sea masks for model products, and identified them as a desired layer for DEMs. Masks are needed for land, oceans, lakes, and rivers. Equal-angle grids are also needed at 0.25, 0.5, and 1.0 degrees. Robert Wolfe and Bryan Bailey will report at the next microSWAMP on who is to prepare the grids and on the resources required.

SWAMP Position on Recompetition for the Data System

Piers Sellers reiterated the SWAMP view that recompeting products in the EOS AM-1 timeframe would not save money, and would increase risk for EOS AM-1 (as discussed in the SWAMP letter to Dr. Kennel dated November 1995).

This was followed by a review of the letter sent from the Project Science Office to the SWAMP (and of the responses from Team members to the letter) setting out a strategy for deciding which products to offer for recompetition. A small working group was formed to prepare a new letter on the topic, to be signed by all Team leaders and by the Project Science Office.

Calibration

Jim Butler reviewed recent progress with instrument calibration work, and discussed lunar calibration. Lunar/deep space maneuvers are desired by the MODIS, CERES, ASTER, and MISR Teams; such maneuvers are not needed (but they are not feared either) by the MOPITT Team.

The current plan is for GSFC to write the flight software needed to implement the maneuvers. The spacecraft should be capable of performing the maneuvers within 6 months after launch.

X-Band Update

Paul Westmeyer discussed the fact that if X-Band were to be used to download science data, there would be a black-out for direct broadcast north of 60 degrees North latitude.

ASTER Ground Track

Ed Chang discussed the request from the Japanese ASTER ground data system (GDS) for ground track margins to be reduced from +/-20 km to +/-2.5 km to facilitate ASTER operations. If this were done, orbit adjust maneuvers (using propellant) would increase in frequency from once every 43 days to once every 14 days (or possibly more often). There was opposition to doing this from other instrument teams.

At the next microSWAMP, the ASTER GDS Team will present the science justification for the tighter ground track requirements, and Ed Chang will discuss the likely frequency of maneuvers as a function of ground track requirements.

ASTER Tilting On Day-Side

Ed Chang also discussed the jitter analysis, indicating that ASTER tilts on the day-side will stay within margins, and will not perturb other instruments. All agreed that we should assess the real impact of day-side tilts in flight before committing to them as a routine, long-term practice.

Data System Working Group

Skip Reber reported that the Data System Working Group (DSWG) has worked hard in response to SWAMP concerns raised in November 1995. Those issues included HDF, browse, metadata, ancillary data, and QA. A high-level one-on-one meeting will be needed to resolve some of these issues. The next DSWG meeting is planned for May 1996.

EOS AM-1 Science Software Review (SSR) Summary

Francesco Bordi summarized the science software reviews that were held the two days preceding the SWAMP:

beta deliveries were a very useful experience for everyone;
remote testing, plus early access to the DAACs are important; recompetition is a concern for all teams;
there has been concern that release B purchases would result in a large software modification burden for the teams; and
there has been some schedule erosion in some teams for Version 1.0.

Data Assimilation Office

Jim Stobie reported on his work on swath data products from the Data Assimilation Office, and announced that a prototype will be available in June 1996.

Model Grid Products

Piers Sellers reported that the MODIS, MISR, and CERES Teams agree to produce model grid products and will send out a revised letter with specifications for the model grid.

Next SWAMP Meetings

Piers Sellers presented the schedule for the next SWAMP meetings: There will be a MicroSWAMP meeting at the EOS IWG meeting on May 13, 1996.

There are two options for the next SWAMP/SSR meeting week (and possibly for some ATBD reviews).

Option 1: November 4-8, 1996.
Option 2: November 11-15, 1996.