Studies On Error Analysis Of Positioning And Real-time Precise Point Positioning

The error is the most direct and important factor affecting the precision of positioning.With the requirement of higher precision, more accuracy and effective error correcting modelsneed to be established. Several error items are deeply researched such as Satellite orbitinterpolation error, Receiver antenna radom error and multipath error. In addition, Real-timePrecise Point Positioning (RT-PPP) has become a research hotspot in the field of GNSS, andin the near future, it will become a major technology in the area of real-time precise kinematicpositioning. The thesis focuses on the key problems of Real-time Precise Point Positioning. ART-PPP method based on regional IGS net with real-time estimation of satellite clock isproposed. Based on it, A new RT-PPP method without using Precise Clock is also researched.Main achievements and contributions are as follows:1. The precisions of6interpolation methods have been quantitatively analysed in GPSorbit interpolation, then a conclusion that6methods have equal principles and consistentresults is drawn.2. Because the above6methods can not reach the precision requirement of GOCE orbitand velocity interpolation, a new interpolation method which has the highest precision andstability is proposed for obtaining the GOCE kinematic orbit velocity.3. The radom varies the antenna phase center which will affect the positioning precision.This effection has a direct proportion relationship with the the elevation angle. Different typesof radoms are compared in order to analyse their influences on relative positioning and PPP.Finally, some advice for radom error correction have been given out.4. The multipath error which is often ignored in precise positioning is studied. WithCMC method, the value of original multipath on5Chinese IGS stations can be calculated.Then LMS algorithm is used to filter original multipath. The result shows that the correctionrate of filter is superior to80%, which will improve the precision of positioning.5. A RT-PPP method with real-time estimation of satellite clock is put forward based onregional IGS net. Its clock bias is greatly corresponding with IGS precise clock product, andthe RMS is superior to0.1ns. RT-PPP with centimeter precision level can be achieved by thismethod.6. Based on the RT-PPP method with real-time estimation of satellite clock, a newRT-PPP method without using precise clock is proposed. The experiment shows that the newmethod not only has low demand number of reference stations, but also has28.8%higher precision than the pre-method in the same condition.