GPS Transmitting Antenna Pattern Modification for Space Service Volume and Its Performance Evaluation

Maolin Chen ； Xingqun Zhan ； Kui Lin ； Yawei Zhai

《Journal of Aeronautics, Astronautics and Aviation》 51卷1期 Vol.51 No.1 (2019/03) Pp. 59-73

https://doi.org/10.6125/JoAAA.201903_51(1).05

摘要

With a rapidly increasing number of spacecraft and satellites, traditional ground-based orbit determination systems, such as Satellite Laser Ranging (SLR), are encountering with irruptive workload and expense. Global Navigation Satellite System (GNSS), with Global Positioning System (GPS) as a representative, based autonomous orbit determination technique appears as a cheaper and more convenient alternative with more and more attentions globally. However, because of some characteristics of GPS signals in Space Service Volume (SSV) compared to those in Terrestrial Space Volume (TSV), such as low signal power, Earth occlusion and other aspects, GPS has not yet been diffusely applied in High Earth Orbit (HEO) spacecraft. Three indexes, namely, Covering Space Ratio (CSR), availability and Dilution of Precision (DOP) are proposed to evaluate the performance of GPS in SSV, and GPS antenna pattern modification criteria are studied in this work. Corresponding modification of transmitting antenna pattern is manipulated and compared with traditional GPS transmitting antenna panels. Performance evaluation is executed in two points of views at a specific point in one day, and at different points at a specific time. Evaluation results demonstrate that GPS performance in SSV could be improved regarding to CSR, availability, and DOP by transmitting antenna pattern modification with only trivial performance degradation in GPS TSV.

關鍵字

Space Service Volume ； Transmitting Antenna Pattern ； GPS ； Covering Space Ratio ； Antenna panel