Service PerformanceNumber of Visible Satellites Position Dilution of Precision Ground Tracks of Satellites User SIS Ranging Error Accuracy of User Positioning
The number of BDS satellites with global visibility at any location is shown in Fig. BDS Number of Visible Satellites. Different colors represent different levels of satellite visibility (See the legend on the right).
The computation of GNSS positioning requires three location parameters and one clock offset parameter, so at least four satellites need to be in view of the receiver simultaneously (positioning accuracy is also related to many other factors). The approximate coverage area of BDS is also illustrated in Fig. BDS Number of Visible Satellites.