CSmasher的博客

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.

RINEX3.03格式说明 The first proposal for the Receiver Independent Exchange Format RINEX was developed by the Astronomical Institute of the University of Bern for the easy exchange of the Global Positioning System (GPS) data to be collected during the first large European GPS campaign EUREF 89, which involved more than 60 GPS receivers of 4 different manufacturers.

ERDAS软件用于遥感图像处理，是应用十分广泛的一个软件。本电子资源，是学习ERDAS软件比不可少的工具。

用于cass软件操作学习，可作为测绘人员的内业指导书。

日常生活中有这样的现象：把椅子往不平的地面上一放，通常只有三只脚着地，放不稳，然而只需稍微挪动几次，一般都可以使四只脚同时着地。试从数学的角度加以解释。