CHEN Chengjian, postgraduate, majors in GNSS PPP enhanced by LEO constellations, E-mail: 235011018@csu.edu.cn
A constellation performance evaluation is conducted using the number of visible satellite and position dilution of precision(PDOP) of three low Earth orbit(LEO) constellations Hongyan, CentiSpace, and Hongyun in China. Simulated LEO data is combined with GNSS observation data from 12 evenly distributed stations to enhance precise point positioning(PPP). The performance enhancement effects of three LEO constellations on GPS/GLONASS/BDS/Galileo PPP are compared and analyzed in static and simulated dynamic modes. The results show that after the enhancement of Hongyan, CentiSpace, and Hongyun LEO constellations, the average static PPP convergence time of all stations is reduced by 64%, 77%, and 80%, the static PPP accuracy is improved by 33%, 36%, and 43%, respectively. The dynamic PPP convergence time is reduced by 67%, 76%, and 86%, the dynamic PPP accuracy is improved by 10%, 17%, and 16%, respectively. Overall, the PPP enhancement performance of CentiSpace and Hongyun LEO constellations is more significant compared to Hongyan constellation, and the enhancement performance is generally positively correlated with constellation size.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |