航空矢量重力测量中有限冲激响应低通数字滤波器的设计

Design of FIR Lowpass Digital Filters for Airborne Vector Gravimetry

基于窗函数法和切比雪夫逼近法设计了两类适用于航空矢量重力测量的有限冲激响应（FIR）低通数字滤波器。先采用模拟高度数据验证了滤波器的性能,然后对实测静态GPS数据进行了低通滤波处理,并详细分析了滤波器的相位延迟和边界效应等影响。结果表明：①在相同的设计指标下,依照切比雪夫逼近法所设计的滤波器比采用窗函数法设计的滤波器具有更好的低通滤波效果;②对于静态GPS测量数据,依照切比雪夫逼近法所设计的滤波器能以±（1-2）mGal（1 mGal=10^-5 m/s^2）的精度确定垂直加速度,以优于±1mGal的精度确定水平加速度。

Two FIR lowpass digital filters were designed for airborne vector gravimetry using window function and Chebyshev approximation. Firstly, simulated heights were used to test the performance of the filters. Secondly, GPS static positioning data was processed using these two filters during data processing phase delay. The boundary effect is discussed explicitly and some conclusions are drawn as follows：① With the same design parameters, Chebyshev approximation gets better results than the window function; ② The accuracy of the accelerations derived from GPS static positioning data are about ±（1-2） mGal in the vertical direction and better than ±1 mGal in the horizontal direction when Chebyshev approximation is used.