小波稳健最小二乘估计的轨道误差校正算法及其在DEM中的应用

针对二次多项式模型去除干涉相位轨道误差时，须对干涉相位其他项的分布性质作假设等问题，给出基于小波多尺度分析的轨道误差去除算法。基于轨道误差相位在干涉图中表现为长波长低频的特性，将不同尺度空间上波长比轨道误差相位波长短的地形残差相位、噪声相位等进行滤除，并采用稳健最小二乘估计二次多项式模型参数，进一步降低残余地形误差相位等对轨道误差多项式拟合的干扰。结果表明，本文方法改正后的干涉图中含有的趋势性轨道误差更少，去除效果更优，可提升多项式拟合结果的可靠性。

Orbit Error Correction Algorithm Based on Wavelet Robust Least Square Estimation and Its Application in DEM

One problem in using the quadratic polynomial model for removing orbital errors is that it is necessary to assume the distribution properties of other interference phase. So, a method based on wavelet multi-scale analysis is proposed to remove orbital errors. Based on long wavelength and low frequency characteristics of orbital error phase, the method filters the phase with shortest wavelength compared to the orbital error in different scale spaces. Then, the robust least square method is used to estimate the parameters of the quadratic polynomial model in order to reduce the influence of residual terrain error phase on orbital errors polynomial fitting. The results show that the corrected interferograms contain less trend error, with better removal effect and higher reliability.