RADAR 시스템과 SGP4 모델을 이용한 저궤도 위성의 실시간 궤도결정

• Published in: Journal of astronomy and space sciences Vol. 20; no. 1; pp. 21 - 28
• Main Authors: 이재광, 이성섭, 윤재철, 최규홍, Jae-Kwang Lee, Sung-Seub Lee, Jae-Cheol Yoon, Kyu-Hong Choi
• Format: Journal Article
• Language: Korean
• Published: 한국우주과학회 01-03-2003
• Subjects: 천문학; radar system; SGP4 model; finite difference; extended Kalman filter; analytical orbit model
• ISSN: 2093-5587; 2093-1409

In case that we independently obtain orbital informations about the low earth satellites of foreign countries using radar systems, we develop the orbit determination algorithm for this purpose using a SGP4 model with an analytical orbit model and the extended Kalman filter with a real-time processing method. When the state vector is Keplerian orbital elements, singularity problems happen to compute partial derivative with respect to inclination and eccentricity orbit elements. To cope with this problem, we set state vector osculating to mean equinox and true equator cartesian elements with coordinate transformation. The state transition matrix and the covariance matrix are numerically computed using a SGP4 model. Observational measurements are the type of azimuth, elevation and range, filter process to each measurement in a lump. After
analyzing performance of the developed orbit determination algorithm using TOPEX/POSEIDON POE(Precision Orbit Ephemeris), its position error has about 1 km. To be similar to performance of NORAD system that has up to 3km position accuracy during 7 days need to radar system performance that have accuracy within 0.1 degree for azimuth and elevation and 50m for range. KCI Citation Count: 1