Abstract:

Positioning accuracy of satellite navigation system is subjected to the influence of observation’s accuracy for pseudorange and the geometrical configuration of constellation.Generally GPS and other similar satellite navigation system using geometric dilution of precision（GDOP）to analyze the positioning accuracy.The transmitting satellite navigation and positioning system CAPS of our country is the mixed constellation navigation system，which is composed of GEO commercial communication satellites and a certain number of inclined geosynchronous orbit（IGSO）satellites.They are used to transmit signals from the ground station to realize like navigation and positioning.Due to the orbit errors for different orbit satellite，pseudo-range measurement accuracy the user received is not the same，so the difference must be considered when calculating positioning accuracy.The weighted dilution of precision（WGDOP）is introduced in this paper，we analyzed positioning accuracy of CAPS satellite navigation system.The simulation results show that positioning accuracy calculating from WDOP can be further improved when the user equivalent range error are the same.

Key words: Chinese area positioning system, satellite navigation, positioning accuracy, sensitivity, weighted dilution of precision