Research On Nonlinear Model For Improving GPS Positioning Precision

GPS (Global positioning system) is a kind of new precise satellite navigation system. Now it has been widely used all over the world and the relative products emerged in endlessly that involve a lot of fields such as vehicle navigation, geographic position and so on. However, the positioning accuracy of the GPS, especially the low-price GPS receiver, sometimes cannot be satisfied and the positioning error may be about 10 or 15 meters. It will be worse when in the urban canyon. It is a big problem that confuses the GPS application.The main reason of such problem is that, first, there are many error sources which reduce the signal quality during the signal-transmission and then reduce the positioning accuracy. Second, the positioning model is faultiness. Because the system equation is changed with time, during the measurement, the statistic character of the system noise and the observation noise cannot be estimated or be determined accurately. As a matter of fact, a lot of noise model cannot be served as the white noise. But the common models always ignore such things so as to reduce the positioning accuracy at a certain extent. At the same time, when doing the...