基于总变分的干涉成像高度计相位滤波方法

宽幅干涉成像高度计采用双天线近天底角短基线干涉测高技术，实现对海洋亚中尺度现象的高时空分辨率与高精度观测。在反演海面高度(SSH)的过程中，干涉相位滤波处理是抑制随机相位噪声，保持相位边缘细节的重要环节。该文针对成像高度计干涉相位随机噪声方差在刈幅范围内分布不均匀的特点，基于宽幅干涉成像高度计相位模型，提出一种改进的总变分正则化滤波方法，可以有效抑制去平地后成像高度计的干涉相位噪声。通过仿真数据验证，滤波相位误差的标准差(STD)由0.32 rad降低至0.023 rad，且刈幅范围内STD最大偏差小于0.001 rad。改进的总变分滤波方法实现全刈幅干涉相位误差精度的均匀分布，较好地保持了分辨率和边缘信息，为海面高程精度的一致性提供有效保障。

Method of Phase Filtering for Wide-Swath Interferometric Imaging Radar Altimeter Based on Total Variation

The wide-swath interferometric imaging radar altimeter with short baseline and at near nadir angles will satisfy the requirement of high precision, high temporal and spatial resolution Sea Surface Height (SSH) for sub-mesoscale ocean features. In the process of retrieving sea level, interferometric phase filtering is an important part of suppressing random phase noise and maintaining the details of phase edges. The varying random noise of flattened phase will be attenuated effectively with total variation regularization filtering which based on the features of noise distribution along the cross-track direction for the altimeter. Simulation results show the STandard Deviation (STD) of the filtered phase error using the proposed method is reduced from 0.32 rad to 0.023 rad, and the maximum deviation is less than 0.001 rad within the swath. The distribution of the phase error accuracy using the proposed method is more homogeneous compared to traditional phase filtering methods. Simulation results also show the proposed method can preserve the resolution and edge information, which provides an effective guarantee for the consistency of sea surface elevation accuracy.