The Application Of Kalman Filter On GNSS Navigation System

With the development of the global navigation positioning system (GNSS), the accuracy of positioning and speed as well as the timing is more and more highly needed. In order to improve the accuracy of GNSS positioning and speed, the Hungarian mathematician Kalman research out the kalman filtering. Because of the good performance of kalman filter, it is widely used in the field of navigation on various occasions, including kalman filter based on doppler smooth, kalman filter based on positioning and speed, and GNSS/SINS integrated navigation and so on.This paper makes a study of the kalman filer in GNSS in the field of navigation application. First of all, this paper introduces the basic principle of kalman filter and its mathematical model. Secondly, this paper introduces several kinds of doppler smoothing method, mainly divided into traditional average doppler smoothing method and kalman filtering doppler smoothing method. Next, because of the insufficiency of kalman filtering positioning calculating, this paper proposes the kalman post-processing method of PVT.This method uses least squares to calculate the receiver basic location information such as receiver position and speed, and then puts the information to the kalman filtering model as the initial value, and then through the kalman filtering calculates the receiver’s position and speed.Finally, in recent years the inertial navigation system is widely used in integrated navigation field, integrated navigation according to SINS and GNSS coupled mode different cent is divided into loosely coupled, tightly coupled and ultra tightly coupled.Tightly coupled and ultra tightly coupled research is difficult, and the development period is long. This paper will prove the combination method of the loosely coupled integrated navigation model and SINS speeding auxiliary to produce another kind of new integrated navigation filtering model.