The meeting was held in Pasadena, CA, on October 29-31, 1996. It was scheduled at this time so that the Science Team could have an opportunity to comment on the material to be presented at the System Concept Review (SCR) at Goddard November 12-14, 1996.
The meeting opened with Joe McNeal (NASA HQ) describing the move of many of the MTPE Program Office functions to Goddard, although Joe, himself, remains as the CHEM Platform Scientist and the TES Instrument Scientist. As always, the budget is under pressure (and will continue to be so) but the decision about splitting up the CHEM platform is still under examination (to be resolved about March 1997 under the current schedule).
The JPL Project Manager, Tom Glavich, then provided an overview of the progress on the instrument design over the past year. While the design continues to improve and evolve, a design freeze was imposed in August so that a detailed cost and schedule for the SCR could be prepared. Following the SCR, design work will continue.
The PI, Reinhard Beer, presented the changes to the science requirements, as reflected in the new version (V 5.0) of the Science Requirements document. The major changes that have been made are:
1) to eliminate the "volcano HF" filter, a) because it has been determined that the Signal-to-noise ration (SNR) would be too low to be useful, and b) because the elmination substantially simplifies the signal chain design;
2) to reduce the scan speed by a factor of 2 in order to a) improve the single-scan SNR by 40%, b) halve the data rate, and c) to halve the uncompensated momentum of the interferometer translator mechanism;
3) to restructure the Global Survey mode observation sequences so that each 80-second set contains 2 "embedded" calibrations (cold sky and Black Body), 2 nadir views, and 3 limb views. The sequences will be repeated continuously on a basic 4-day-on-4-day-off cycle, with each 4-day set being preceded and followed by 2 orbits of continuous calibration. The changes were made as a consequence of our experience with the TES aircraft precursor, AES, where we have found that "there is no such thing as too much calibration;" and
4) to decrease the interchangeable foreoptic demagnification from the original 10:1 to 5:1, thereby providing a better match between the limb and nadir footprints.
Most of the rest of the day was given over to the various sub-system groups, introduced by Al Conrad (the recently-appointed TES Instrument Manager at JPL). The intent here was to provide the Science Team both with an overview of the current instrument design and a preview of the material to be presented at the SCR.
The first day concluded with Reinhard Beer presenting a preliminary set of acceptance criteria for the TES instrument. While apparently premature (the instrument does not yet exist!), the criteria are essential to the Integration & Test and Calibration Teams' future planning.
The second day began with Reinhard Beer presenting a first cut at the Standard Product (Global Survey) mode mission timeline, including all calibration sequences. The basic decision has been made to run TES "by the clock," beginning with the ascending node crossing at the beginning of each 4-day cycle. This will greatly ease the development of the flight software.
Most of the rest of the meeting (1-1/2 days) was given over to progress on algorithm development. Levels 1A & 1B are quite well-defined but Level 2 (species retrievals) is still being formulated. Some preliminary segments have been delivered to the software development team but, for example, it is yet to be decided whether the Jacobians should be calculated analytically or by finite differences. Also undecided is the mechanism for determining whether or not convergence has been achieved. However, it was decided that we should attempt to use as much as possible of the prior work by MODIS, MOPITT, and AIRS for cloud detection/clearing and their ATBDs will be carefully studied.
The question of a Level 3 (Mapping) algorithm received considerable discussion. In view of the great progress being made in data assimilation techniques, it was decided that an extensive effort in this area is unwarranted and we shall probably provide no more than a Measurements of Air Pollution from Satellites (MAPS)-type binned browse product, whose development is straightforward (and, above all, can be postponed).
During this period of intensive discussion, relief was offered by Daniel Jacob (Harvard University), who gave an overview of his plans for his recently-accepted Tropospheric Chemistry IDS team and by David Rider (JPL), who described progress on analysis of AES data from the 1995 Southern Oxidants Study (SOS) Nashville-Middle Tennessee Intensive Campaign and plans for the forthcoming (Nov - Dec 1996) deployment on the DC-8 as a secondary experiment on the AirSAR Pacific Rim Experiment. During the ferry flights, we shall obtain numerous spectra of many different types of clouds and (we hope) some clear-sky over-the-ocean data. In concert with TIMS (Thermal Infrared Mapping Spectrometer, an ASTER precursor), we shall also attempt to obtain spectra of volcanic plumes from Pu'u O'o, Hawaii, and White Island, New Zealand.
We wish to record our appreciation of Patricia Mclane (JPL) and her Conference Administration Office for their excellent organization of the meeting.
The next TES Science Team meeting will be held at Harvard University, provisionally, June 11-13, 1997.