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Optimizing Orbit-Instrument Configuration for Global Precipitation Mission (GPM) Satellite FleetFollowing the scientific success of the Tropical Rainfall Measuring Mission (TRMM) spearheaded by a group of NASA and NASDA scientists, their external scientific collaborators, and additional investigators within the European Union's TRMM Research Program (EUROTRMM), there has been substantial progress towards the development of a new internationally organized, global scale, and satellite-based precipitation measuring mission. The highlights of this newly developing mission are a greatly expanded scope of measuring capability and a more diversified set of science objectives. The mission is called the Global Precipitation Mission (GPM). Notionally, GPM will be a constellation-type mission involving a fleet of nine satellites. In this fleet, one member is referred to as the "core" spacecraft flown in an approximately 70 degree inclined non-sun-synchronous orbit, somewhat similar to TRMM in that it carries both a multi-channel polarized passive microwave radiometer (PMW) and a radar system, but in this case it will be a dual frequency Ku-Ka band radar system enabling explicit measurements of microphysical DSD properties. The remainder of fleet members are eight orbit-synchronized, sun-synchronous "constellation" spacecraft each carrying some type of multi-channel PMW radiometer, enabling no worse than 3-hour diurnal sampling over the entire globe. In this configuration the "core" spacecraft serves as a high quality reference platform for training and calibrating the PMW rain retrieval algorithms used with the "constellation" radiometers. Within NASA, GPM has advanced to the pre-formulation phase which has enabled the initiation of a set of science and technology studies which will help lead to the final mission design some time in the 2003 period. This presentation first provides an overview of the notional GPM program and mission design, including its organizational and programmatic concepts, scientific agenda, expected instrument package, and basic flight architecture. Following this introduction, we focus specifically on the last topic, that being an analysis which leads to an optimal flight architecture dictated in part by science requirements but constrained by allowable orbital mechanics, instrument scan patterns, and antenna aperture properties. Because the optimal architecture involves an interplay between orbit mechanics and instrument specifications, it is important to recognize that in attempting to serve various scientific themes, the final optimal architecture will represent a compromise concerning dynamic range, spatial resolution, sampling interval, pointing, beam coincidence, and measurement uncertainty. Moreover, cost becomes a major factor in seeking the optimal architecture through the pathways of antenna and instrument scan designs, as well as propulsion requirements associated with the orbit heights of various "constellation" members. Although the results presented at the IGARSS-2001 meeting will likely not be the fully refined flight architecture specifications, they are expected to be nearly complete.
Document ID
20020005414
Document Type
Conference Paper
Authors
Smith, Eric A. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Adams, James (NASA Goddard Space Flight Center Greenbelt, MD United States)
Baptista, Pedro (European Space Agency. European Space Research and Technology Center, ESTEC Noordwijk, Netherlands)
Haddad, Ziad (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Iguchi, Toshio (Communications Research Lab. Tokyo, Japan)
Im, Eastwood (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Kummerow, Christian (Colorado State Univ. Fort Collins, CO United States)
Einaudi, Franco
Date Acquired
August 20, 2013
Publication Date
January 1, 2001
Subject Category
Meteorology and Climatology
Meeting Information
IEEE IGARSS 2001 Meeting(Sydney)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.