论文部分内容阅读
具有波形记录功能的星载激光测高仪,通过回波信息解算地表与卫星平台距离和反演地物特性。目前广泛采用的固定宽度高斯滤波方法在抑制回波噪声过程中造成有效信号变形,对提取信号有效参量造成严重干扰。根据分块信号统计特性不同的规律,提出了激光测高仪回波噪声均值和方差的估计方法;根据回波信号的统计特性,设计了一种宽度自适应的高斯滤波器。通过GLAS系统实测回波信号的噪声估计与自适应高斯滤波、高斯拟合,得到的波形处理结果与GLAS官方数据有很好的吻合度,噪声均值估计误差小于0.4个数字化仪单位,有效高斯参数计算误差小于1%。该方法能准确地提取波形参量,为地表高程解算和目标表面信息反演提供有效数据。
The spaceborne laser altimeter with waveform recording function solves the distance between the surface and the satellite platform and inversions the features of the terrain by echo information. The widely used fixed-width Gaussian filter method in the suppression of echo noise caused by the effective signal distortion, the effective parameters of the extracted signal caused serious interference. According to the different statistic characteristics of the block signal, a method of estimating the mean and variance of echo noise of laser altimeter is proposed. Based on the statistical characteristics of the echo signal, a Gaussian filter with adaptive width is designed. The GLAS system measured echo signal noise estimation and adaptive Gaussian filter, Gaussian fitting, the resulting waveform processing results and GLAS official data have a good agreement, the noise mean estimation error is less than 0.4 digitizer unit, the effective Gaussian parameter The calculation error is less than 1%. The method can accurately extract the waveform parameters and provide valid data for the solution of surface elevation and the inversion of target surface information.