FORMOSAT-3 (a.k.a. COSMIC in the U.S.) is the first largest space collaboration program between Taiwan and the U.S. The program employed 6-micro satellites formed in global constellation that utilize the Radio Occultation (RO) technique to receive the L-band signals from the GPS satellites. The retrieved GPS RO signals then processed into the useful weather data to form the near-real time global weather observation network. The FORMOSAT-3 constellation will reach the 10^th Anniversary since its launch on April 15, 2006. The accumulated retrieved RO soundings have exceeded 10 million profiles (6 million for the atmosphere and 4 million for the ionosphere) in the past decade. These RO data have been continuously provided to more than 3,000 registered users in 83 countries. The GPS-RO data has been demonstrated to be valuable to the climate, meteorology, and space weather communities.

The much frequenter sever weathers formation due to the rapid global environment change has been raised as one of the most critical matters among the global atmosopheric and earth scientists. The unique feature of radio occultation technique can overcome the conventional difficulties to retrieve the data from the oceans and polar regions with abundant quantity in near-real time that are very useful to improve the weather forecast accuracy, climate change observation, and global warming researches. European Center for Middle-Range Weather Forecast (ECMWF) reported that the FORMOSAT-3 RO data accounted only 2~3 % among the total data used in the weather forecast assimilation in 2012 has contributed to a 10% forecast error reduction that is a significant increased from 8.5% as studied in 2008. FORMOSAT-3 RO data was ranked #5 among the most significant contribution weather observation programs in the world. Other than Central Weather Bureau in Taiwan, many major weather forecast centers and agencies in the world, such as Canada, United States, United Kingdom, Japan, Australia, Korea, many nations in European Union, have incorporated the RO data in their weather forecast assimilation system. It's unprecedented that FORMOSAT-3 constellational RO can attract the global attentions and incorporated into the weather forecast systems within a short period of time.

A case study by Taiwan Typhoon and Flood Research Institute (TTFRI) of the NARLabs utilized 23 typhoons in 2012 indicated that the RO data can improve 10% in typhoon track accuracy for 24-hours advanced forecast. Taiwan scientist team also used the RO data to successfully establish the first near-real time and 3-dimentional (3-D) global ionospheric observation network and forecast assimilation model in the world. The 3-D ionospheric forecast assimilation model is useful for accuracy improvement and correction in communication, positioning, navigation.

The FORMOSAT-3 constellation system retrieved ~ 2,400 RO profiles per day at the initial operation period since its launch in April 2006. Over near 10-year operations, other than one satellite was declared decommissioned due to the un-recoverable power failure, the other five satellites are currently exhibiting intermittent outages caused by the power system failure and the decaying performance due to the aging of many key components in each satellite. Never the less, the FORMOSAT-3 constellation is currently contributing at 650~850 RO profiles daily. The FORMOSAT-3 RO Constellation has been proven to have significant societal impacts to increase the accuracy of the predictions of hurricane / typhoon behavior, improve the long-range weather forecasts, and monitor the climate change with unprecedented accuracy.

Taking the opportunity of the 10^th Launch Anniversary, NSPO is hosting the 3^rd ICGPSRO 2016 (International Conference on GPS Radio Occultation) at Howard International House in Taipei during March 9 and 11, 2016. There are expected to have more than 180 from 20 countries to gather in this conference. More than 90 submitted papers and posters to be presented and shared of the new findings and the opinions of the RO data utilizations and applications. NSPO will also update the progress made toward the readiness of the new FORMOSAT-7 constellation that will replace the decaying FORMOSAT-3 constellation in orbit.

NARLabs Contacts

NSPO Nick Yen tel: 03-578-4208#1053 / 0910-148863 email: longine@nspo.narl.org.tw
NSPO H.-J. Yu tel: 03-578-4208#8273 / 0922-432275 email: hjyu@nspo.narl.org.tw
NSPO S.-C. Chang tel: 03-578-4208#8093 / 0926-252237 email: chien@nspo.narl.org.tw
NARL Tom Lee tel: 02-6630-0622 / 0931-162081 email: tomlee@narlabs.org.tw