Self-adaptive filtering method for carrier smoothed code pseudorange

The invention provides a self-adaptive filtering method for a carrier smoothed code pseudorange. The method includes the steps: constructing a Kalman filtering basic equation, estimating and performing self-adaptive adjusting on a system noise error through the maximum likelihood criterion, carrying out carrier smoothed code pseudorange Kalman filtering, and obtaining the estimated system noise error after iteration. According to the method, the system noise is obtained without statistic analysis of a carrier smoothed code pseudorange system before filtering, a system noise empirical value is provided to serve as an initial value, and self-adaptive adjusting is performed on the system noise error during a subsequent process. In this way, pseudorange smoothed result errors caused by cycle slips are prevented from being too serious, and a filtering effect in a cycle clip condition is better than a conventional Kalman filtering effect.