IGS_CLK格式说明

Thus far, the IGS has produced clock results only for the GPS satellites and these are tabulated and distributed at the 15-minute intervals used in the sp3 orbit ephemerides files. There is much interest in increasing the satellite clock interval to 30 seconds (e.g., to overcome SA effects on interpolation) and also in producing station clock results (at some appropriate interval, probably 5 minutes). In principle, the sp3 format could continue to be used for both of these extensions, but it would be wasteful considering that the vast majority of the file space is set aside for orbit information. Also, the variety of other clock information that also needs to be exchanged does not lend itself to the sp3 format.