Availability Of GPS Signal Evaluation And Positioning Accuracy Improvement Method Research

GPS from the initial military application to now is widely used in various fields, whichhas got rapid progress, and is closely related to people’s life. And technology has been verymature, whether GPS timing services or positioning navigation, in ideal conditions itsprecision can meet the needs of the people. But in actual condition, especially in high-riseserried cities, there are all kinds of interference, including high floor, viaduct, roadside trees,and receiver antenna multipath effect and so on, cause GPS signal is not one hundred percentof available, positioning accuracy is of great influence.Availability of GPS signal evaluation and improving the accuracy of GPS positioning areboth studied in this paper.First of all, this paper introduces several factors related to the availability of GPS signal,including GPS positioning precision factor, the influence of the multipath effect, etc. And inthe actual experiment, with NI company labview as a platform, through the writing of GPSsignal receiving and processing software, the availability of GPS signal is analyzed. Theparticular area within a period of time of GPS signal availability is calculated, in order toobserve the GPS signal availability and accuracy of factor, the relationship between thenumber of visible satellite, etc.Secondly, because the reality environment GPS signal was screened and interfereed, thepositioning accuracy is affected. Eliminate GPS random error is the important method ofdynamic filter. The extended kalman filtering is applied to GPS positioning system, andkalman filtering is minimum variance of the optimal estimation. The mathematical model ofGPS positioning system is set up, and the quantity of state real value is estimated out fromrandom disturbance of optimal. In the experiments, GPS signal receiving and processingsoftware and the established extended kalman filtering model are combined, and realize thefiltering process with matlab.The results show that the established GPS positioning systemmodel is accurate, and play a certain improvement action on the GPS positioning precision.In short, through the research of the availability of GPS signal evaluation and extended kalman filtering method applied to the GPS positioning system in this article, we understandthe influence factors of GPS signal usability, and improve the positioning accuracy of the GPSreceiver, and is valuable in real life.