The Most Accurate and Stable Space-Borne Thermometers

Nick Yen , Chung-Huei Vicky Chu, Chen-Joe Fong, Tie-Yue Liu, and Shiao-Shing Chen

National Space Organization (NSPO)

8F, 9 Prosperity 1st Road, Science Based Industrial Park, Hsin-Chu, Taiwan; 011-886-35784208

longine@nspo.org.tw, vicky@nspo.org.tw, cjfong@nspo.org.tw, tie@nspo.org.tw,sschen@nspo.org.tw

Yuei-An Liou

Center for Space and Remote Research, National Central University

Chung-Li, Taiwan; 011-886-34581196 ext 5000

yueian@csrsr.ncu.edu.tw

Bill Kuo

University Corporation for Atmospheric Research

Boulder, Colorado, USA; 1-303-497-8910

kuo@ucar.edu

ABSTRACT

The FORMOSAT-3 Constellation also known as COSMIC mission (Observing Systems for Meteorology, Ionosphere, and Climate) mission, was launched successfully from Vandenberg Air Force Base in California 1:40 UTC on April 15, 2006 into the same orbit plane of the designated 516 km circular parking orbit altitude. The FORMOSAT-3/COSMIC spacecraft constellation consisting of six LEO satellites is the world's first operational GPS radio occultation mission. The mission was initiated by the National Science Council of Taiwan and the National Science Foundation of the US. The satellite constellation program was jointly developed by National Space Organization (NSPO) in Taiwan and University Corporation for Atmospheric Research (UCAR) in US in collaboration with other US agencies including USAF for the Minotaur launch system, NASA's Jet Propulsion Laboratory (JPL) and Naval Research Laboratory (NRL) for three onboard payloads including GPS Occultation Receiver (GOX), Tri-Band Beacon (TBB), and Tiny Ionospheric Photometer (TIP). All six FORMOSAT-3/COSMIC satellites are maintained in the good state of health conditions to carry the mission. All six spacecraft are on their way toward the final constellation of six separate orbit planes with 30-degree separations by the mid-December of 2007. The FORMOSAT-3/COSMIC has processed over 1800 good atmospheric sounding profiles per day in average (prior to all spacecrafts reaching the final constellation) which has over the number of worldwide radiosondes launched per day (~900 mostly above the land mass), and 2500 plus good ionospheric sounding profiles per day, respectively. The FORMOSAT-3/COSMIC data have been attracted worldwide attention. Up to July 2007, there are more than 540+ data users in over 40 nations. The atmospheric radio soundings data are assimilated into the Numerical Weather Prediction (NWP) models for real-time weather prediction and typhoon/hurricane forecast. Many major weather centers including NOAA/NCEP and NESDIS of US, ECMWF of EU, Met Office of UK, IEEC of Spain DMI of Denmark have begun to use the FORMOSAT-3/COSMIC data in the assimilation process for weather forecasts. The radio occultation as received is regarded as the most accurate and stable thermometer in space. This paper describes the constellation mission program up-to-date status; six spacecraft system performance; the highlighted state-of-the-art science results; and the future follow-on mission planning progress.