The Method Research And Program Realization Of GPS/BDS Baseline Solution

The Beidou system is an independent system developed by our country.It is another perfect system after GPS and GLONASS.With the continuous development of GNSS,especially the construction and improvement of Beidou system in China,the combination of multi-frequency and multi-system will be another trend of GNSS navigation and positioning technology;multi-system combination can improve the redundancy,improve the accuracy of navigation positioning and improve the stability of navigation and positioning.The main contents of this paper are as follows:1)The domestic and foreign research level of GPS/BDS baseline solution,error sources in GPS and BDS system and GNSS positioning and their correction methods are described.2)This paper introduces the coordinate system and time system of GPS and BDS system,the satellite position calculation of GPS and BDS system,and studies the unified problem of GPS and BDS system in space-time datum.On this basis,the function and stochastic model of GPS/BDS relative positioning are studied.3)In this paper,the cycle slip detection,Kalman filter for GPS/BDS baseline solution is studied to calculate the floating point solution and the fixed integer ambiguity of LAMBDA method.The calculation steps of LAMBDA method are also introduced.4)Through the example of GPS/BDS baseline solution,the relationship between precision and system,the relationship between precision and observation period,the relationship between precision and observation time and the comparison of repeated baselines are studied.It is concluded that the accuracy of GPS is slightly higher than that of BDS,and the accuracy of GPS/BDS is higher than that of single GPS and single BDS;the time of 12:00-15:00 should be avoided as far as possible in data collection;when the observation time is short,the geometric structure of the satellite is relatively poor,and the positioning accuracy is lower;the quality of the data for three consecutive days is roughly the same,and the trend of variation is consistent among different systems.Finally,through the research of the related theory of GPS/BDS baseline solution,the program of GPS/BDS baseline solution is compiled,and the correctness of the program is verified by an example.