Random Optimization Algorithm on GNSS Monitoring Stations Selection for Ultra-Rapid Orbit Determination and Real-Time Satellite Clock Offset Estimation

Table 2

Average accuracy and calculation time statistics of 3 consecutive days for probability and traditional methods.

Number of stations	GRID observed; orbit (cm)	GRID predicted orbit (cm)	GRID real-time clock offset(ns)	WSDOP observed orbit (cm)	WSDOP predicted orbit (cm)	WSDOP real-time clock offset (ns)	Increasing rates of observed orbit (%)	Increasing rates of predicted orbit (%)	Increasing rates of real-time clock offset (ns)	Computation time of WSDOP station selection (min)	Computation time of orbit determination (min)	Computation time of clock offset estimation (min)
10	22.93	43.73	0.89	9.37	19.10	0.37	59.16	56.33	58.43	2.22	5.88	1.23
20	4.57	9.40	0.36	3.77	8.03	0.21	17.52	14.54	42.20	3.34	6.57	4.84
30	2.27	5.70	0.30	2.01	4.93	0.20	11.40	13.45	32.58	4.38	7.41	12.33
40	2.13	5.40	0.28	1.76	4.47	0.20	17.65	17.28	28.92	5.52	8.62	27.82
50	1.87	4.67	0.26	1.73	4.13	0.19	7.14	11.43	27.85	6.65	9.81	56.43
60	1.53	3.77	0.26	1.47	3.50	0.17	4.12	7.08	33.77	8.02	11.39	103.57
70	1.37	3.73	0.23	1.20	2.93	0.19	11.99	21.43	17.65	9.97	12.63	170.33
80	1.37	4.00	0.22	1.15	3.17	0.18	15.59	20.83	19.40	12.71	14.68	259.76
90	1.27	3.53	0.23	1.14	3.13	0.18	9.75	11.32	23.19	14.15	16.82	358.04

Note: the station selection is performed with a conventional computer while the orbit and clock calculations are made with a graphics workstation.