대한원격탐사학회:학술대회논문집 (Proceedings of the KSRS Conference)
- 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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- Pages.394-396
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- 2007
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- 1226-9743(pISSN)
Open Loop Technique in FORMOSAT-3/COSMIC mission
- Yeh, Wen-Hao (Department of Electrical Engineering, NCU) ;
- Chiu, Tsen-Chieh (Department of Electrical Engineering, NCU) ;
- Liou, Yuei-An (Center for Space and Remote Sensing Research, NCU, Institute of Space Science, NCU) ;
- Huang, Cheng-Yung (National Space Organization)
- 발행 : 2007.10.31
초록
Radio occultation (RO) technique has been used in planetary science since 1960s. When signal goes through atmosphere, it is refracted due to the gradient of atmospheric refractivity. In 1995, the first low earth orbit (LEO) satellite, MicroLab-1, was launched to conduct RO mission. It receives the signal from global positioning system (GPS) satellites. After MicroLab-1, other RO missions, such as CHAMP, SAC-C, and GRACE, are executed in several years later. In 2006, Taiwan launched six LEO satellites for RO mission. The mission name is Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC). Under some abnormal situations, multipath and strong fluctuation in phase and amplitude of the signal appear in moist troposphere. Therefore, open loop (OL) technique has been applied to replace traditional phase lock loop (PLL) technique. In this paper, we will summarize the retrieval processing procedure and discuss the advantages and disadvantages of OL technique.