SA建模的功率谱分析法

探讨了ＧＰＳ导航信息中的ＳＡ建模的功率谱分析法，即采用ＦＦＴ对ＴＡＮＳ－２接收机记录的ＧＰＳ静态定位误差样本作功率谱分析，通过最小二乘拟合获得ＳＡ的平稳线性模型，并用车载组合导航系统的仿真结果验证了近似模型的有效性。

Power-Spectrum-Analysis Model for Reducing SA in GPS C/A Code Signal

SA contained in GPS C/A code signals brings, under certain conditions such as aircraft landing, disadvantases. For reduction of SA, I deem it very helpful to establish its model.We now explain how the model is established. GPS static position error samples recorded (Fig. 1) with TANS-2 receiver are analyzed in frequency domain via FFT to obtain the SA power spectrum. The SA linear model (the first order Markovian process) is obtained approximately via least-squares fit and its parameters are given in Table 1.Simulation results of the vehicle integrated navigation system are shown in Fads. 2, 3 and 4. The solid-line curve in each of the three figures is always closer to the short - dash curve and thus indicates clearly that the SA model is effective in the reduction of SA.