Algorithm Research And Software Implementation Of GPS/GALILEO Integrity

Integrity is a very hot topic in the research of GNSS. Integrity is defined as that the ability of system gives alarm to the user when the navigation system cann't be use to navigation due to its fault. It can be divided into three levels:system level, monitor station level and user level. Based on GPS data and GALILEO simulation data, this paper mainly discuss the several parameters in system level and monitor station level, and then a GPS/GALILEO integrity is compiled by use of VC++and FORTRAN program language. The main research contents are as follows:1. The quality of L2C SNR data modulated on the modern satellites is analyzed. It mainly studies from two aspects:firstly, analyzing the SNR values on the L1 and L2 frequencies of the satellites unmodulated L2C and the L1 and L2 frequencies of the modernized satellites, and then use the method of statistical analysis to analyze and verify the stability of the data.2. The concept, model and calculation method of worst user location are studied. It is divided into three stepts:firstly, discuss the basic concept of worst user location, then research on the calculation method and propose a new iterative method, finaly verify this method.3. The basic concept and mathematical principle of signal in space error and signal in space accuracy are discussed. Based on the results of worst user location, signal in space error is calculated and analyzed using the navigation data, observation data, SP3 data and IGR data, SP3 data to simulate orbit error separately. Based on that, a t distribution statistics is structure to calculate and analyze the signal in space accuracy.4. The basic concept, mathematical model and data process method of signal in space monitor accuracy are researched. Based on the signal in space error, the calculation method of signal in space monitor accuracy is proposed and vertfied by using navigation data and IGR data, and then the characters of signal in space monitor accuracy are analyzed.5. The basic concepts and mathematical models of horizontal/ vertical protection level are studied. Firstly, the calculation model of horizontal/ vertical protection level are presented, and then horizontal/ vertical protection level are calculated and the differences of GPS and GALILEO system are compared by using GPS data and GALILEO simulation data. 6. GPS/GALILEO integrity is compiled and developed and the availibity is testified by using GPS/GALILEO data.