gps导航工具包，可用于分析GPS误差，伪距及导航融合算法-This report include the review of　

•　Principle of Radio Navigation: navigation base on trilateration has been investigated and the over determined Eq. for navigation has been solved.　

•　GPS Ephemeris Data: for GPS navigation, the position of GPS satellite is very important so the by receiving ephemeris data the position of the satellite is determined.　

•　GPS Errors: Three different sources of errors in GPS navigation has been investigated (Ionosphere, Troposphere and Satellite clock). Ionospheric Error model is generated base on Parkinson [1] and the Tropospheric Error Model based on Hopfiel model [2].　

•　Simulation & GPS Toolbox: One of the targets of this work is generating Matlab GPS Toolbox and in one case study the performance of generated toolbox will be verified.