The tropospheric delay information of the enhanced precise point positioning (PPP) comes from a small regional reference station network with station spacing of several tens of kilometers, which has the disadvantages of limited service scope and high construction cost. To investigate the impact of wide-area tropospheric delay models with larger station spacing on PPP augmentation performance, observational data from IGS tracking stations in Europe were used to establish tropospheric delay models with average inter-station spacings of approximately 200 km, 260 km, 320 km, and 380 km. These models were then compared with the GPT3 model to evaluate and analyze PPP enhancement performance. The results indicate that the wide-area tropospheric delay models with inter-station spacings of 200 km, 260 km, and 320 km all reduced PPP convergence time to varying degrees, with particularly notable improvements in the height component and its maximum enhancement can reach 39.8%. However, the enhancement effect diminished as average station spacing increased. When the station spacing reached 380 km, the PPP augmentation performance was inferior to that of the global GPT3 model.
| 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 |