Ultra-Rapid (predicted half) 和Ultra-Rapid (observed half）区别与联系-详情

2020-2-19 16:30:19 来源: GNSSer 发布人:

IGU由两个24小时组成，看IGU文件的大小就是igs精密星历sp3文件大小的两倍。

The IGU products will contain 48 hours worth of orbits. The first 24 hours contain a "real" orbit, i.e., an orbit based on actual observations. The

second 24 hours contain a predicted orbit.

前24h是使用了观测数据解算的那部分，后24h是使用了解算的部分，然后轨道通过轨道动力学积分外推出来，钟差是用线性多项式（有可能加周期性）外推出来的。

见下图IGS官网给出的详细值。

Type		Accuracy	Latency	Updates	Sample Interval
Broadcast	orbits	~100 cm	real time	—	daily
Broadcast	Sat. clocks	~5 ns RMS ~2.5 ns SDev	real time	—	daily
Ultra-Rapid (predicted half)	orbits	~5 cm	real time	at 03, 09, 15, 21 UTC	15 min
Ultra-Rapid (predicted half)	Sat. clocks	~3 ns RMS ~1.5 ns SDev	real time	at 03, 09, 15, 21 UTC	15 min
Ultra-Rapid (observed half)	orbits	~3 cm	3 – 9 hours	at 03, 09, 15, 21 UTC	15 min
Ultra-Rapid (observed half)	Sat. clocks	~150 ps RMS ~50 ps SDev	3 – 9 hours	at 03, 09, 15, 21 UTC	15 min
Rapid	orbits	~2.5 cm	17 – 41 hours	at 17 UTC daily	15 min
Rapid	Sat. & Stn. clocks	~75 ps RMS ~25 ps SDev	17 – 41 hours	at 17 UTC daily	5 min
Final	orbits	~2.5 cm	12 – 18 days	every Thursday	15 min
Final	Sat. & Stn. clocks	~75 ps RMS ~20 ps SDev	12 – 18 days	every Thursday	Sat.: 30s Stn.: 5 min