Improvement and Simulation of an Autonomous Time Synchronization Algorithm for a Layered Satellite Constellation

Table 2

Comparison of least squares fitting results of different time lengths of the GEO and MEO satellites in the same period (on June 1, 2008, the actual clock offset is 1 𝜇s).

Period	23:32:50.00 to 23:42:50.00	23:27:50.00 to 23:47:50.00	23:22:50.00 to 23:52:50.00	23:22:50.00 to 23:42:50.00; (asymmetrical)
Pseudorange fitting polynomial	𝑅=0.0004620897𝑡^2−0.2767866515𝑡+14843.9503933924	𝑅=0.0004601381𝑡^2−0.5525447643𝑡+14968.4674054507	𝑅=0.0004569549𝑡^2−0.8239841380𝑡+15174.4148791739	𝑅=0.0004594126𝑡^2−0.8273193074𝑡+15175.1192383119
Pseudorange minimum value moment corresponding to 𝜌min (s)	299.4944839741193	600.411855223807	901.603341546627	900.4098268430367
Clock offset fitting polynomial	Δ𝑡=−1.53961927325𝑡+1462.39429390793	Δ𝑡=−0.77368332728𝑡+1464.46555576661	Δ𝑡=−0.51949244881𝑡+1467.72268747967	Δ𝑡=−0.58308473555𝑡+1505.84764677203
Minimum clock offset Δ𝑡min(ns)	1001.286814148183	999.9369138812618	999.3465597276504	980.8324209975162