卫星高度计定标中GPS浮标测量海面高的FIR低通滤波方法

Method of Finite Impulse Response Filtering of Sea Surface Height Measured by GPS Buoy in the Application of Satellite Altimeter Calibration

针对GPS浮标用于卫星高度计定标时需要从瞬时海面高观测值中提取平均海面高的需求,研究了其有限冲激响应低通滤波方法。分析了窗函数设计法中几种窗函数的幅频响应特性,讨论了低通滤波器截止频率的确定原则,给出了滤波器阶数的确定方法。基于浮标测量海面高仿真序列的计算结果表明,不同窗函数的滤波效果相差不大;实际定标应用中滤波器的截止频率可设计为需要滤除海浪信号最低频率的一半,滤波器阶数可根据此设置频率计算得到。

Towards the requirement of distilling mean sea surface height（ SSH） from measured instantaneous SSH in the application of satellite altimeter calibration using GPS buoy,low-pass filtering method using finite impulse response（ FIR） filter is studied. The amplitude-frequency characteristics of different window functions using window function method are analyzed,the principle of determining the cut-off frequency of FIR is proposed,and the method of determining filter＇s order is given. Based on simulated SSH measured by buoy,results show that impact of using different window functions are almost the same,the cut-off frequency is suggested to be set as half the lowest frequency of the signal need to be filtered,and the filter＇s order can be calculated by this frequency.