Near Real-Time Automatic Orbit Determination for the FORMOSAT-3/COSMIC Mission

• Main Author: 彭千惠
• Other Authors: 黃金維
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/66902074392201019650

碩士 === 國立交通大學 === 土木工程學系 === 98 === This research is focused on establishing an automatic near-real time (NRT) system for the orbit determination (OD) of the FORMOSAT-3/COSMIC (F3/C) satellite mission. With Bernese 5.0 for OD, emphasis is on achieving an optimal accuracy of the F3/C NRT orbit. With a portable batch and routine task scheduling under a Linux PC cluster, the system carries out automatic OD for the six satellites of F3/C. Without the final orbits and high-rate clocks of the GPS satellites, the accuracy of the NRT orbits is about 20 cm, based overlapping arc analysis and comparisons with UCAR NRT orbits. With a 15-cm threshold of 3D orbit error, the average success rate of the NRT orbit (percentage of orbit error < 15 cm) is about 40%. Simulations show that, (1) use of improved GPS orbits (from 10 cm to 5 cm), the F3/C NRT orbit accuracy is improved to 15 cm and the success rate increases to 70%. (2) use of 30-s high-rate GPS clocks (with a 0.01ns accuracy), the F3/C NRT orbit accuracy is improved to 10 cm and the success rate increases to 80%.