Analysis of Spectrum Characteristics of GPS Time Comparison Under Two Conditions
Hu Jinlun;Jian Shuguang (Shanghai Observatory, Academia Sinica, Shanghai 200030)
At the beginning of 1992, some experiments were carried out in order to understand the characteristics of GPS time comparison affected by SA (Selective availability) effect. The sampling time of data is 10s and the tracking period of satellite is 1h in the experiments. The results of spectral analyses are shown as follows: 1)Under normal conditions, the spectrum characteristics of GPS time comparison are basically smooth, there are no obvious periodic phenomena and the noise process is white noise PM. 2) When GPS time comparison is affected by SA effect, the low spectra are relatively obvious, and there are obvious periodic phenomena. The periodic signals of 5～15 min take up about 77% among these obvious periods. That is the reason which leads to a marked drop in precision of GPS time comparison.
【CateGory Index】： TN911.6