改进的卡尔曼滤波算法在罗兰C系统中的应用

Application of Modified Kalman Filter to LoranC System

根据罗兰C无线电导航系统中时差信号的变化特征,分析了在新型的罗兰C数字接收机中,三阶卡尔曼滤波模型用于时差滤波的可行性,大量的仿真结果表明由于时差测量时间间隔的减小,该模型具有优良的性能。实际中提取的时差信号会有一些±10μs的大的偏差,针对时差信号的这种“跳周”现象,提出了改进的两级开环卡尔曼滤波算法,实验数据的分析结果验证了该算法的有效性。

According to the character of Time Difference（TD） signal variance in Loran- C system, the feasibility of three dimension Kalman filter model is analyzed in the new digital Loran-C receiver. Through large amount of simulation results,this model shows its good performance because of the decrease of TD measuring intervals. Practically,there are some bias errors of 10 μs among the obtained TD signals. To solve this problem of “Jumping Cycle”,the modified two- order open loop Kalman filter algorithm is proposed, and the validity of the algorithm is proved through analyzing the experiment data.