一种新的低频超宽带干涉合成孔径雷达绝对相位估计方法

A Novel Absolute Phase Determination Approach for Low Frequency Ultra-wideband SAR Interferometry

该文针对低频超宽带(UWB)干涉合成孔径雷达(In SAR),提出一种新的干涉相位绝对值估计方法。该方法首先对干涉图像进行非参数模型的精配准,并利用配准偏移量生成配准相位。然后将配准相位从干涉相位中去除,得到失配相位。最后估计失配相位的绝对相位,进而得到绝对干涉相位的值。该方法利用失配相位具有无相位缠绕或只在相干性较差区域存在相位缠绕的特性估计其绝对相位,相比传统的绝对干涉相位估计方法具有更小的运算复杂度。P波段UWB In SAR实测数据处理结果验证了该方法的有效性。

Estimation of topography for the generation of Digital Elevation Models （DEM） requires the absolute interferometric phase. However, the existing absolute phase determination methods are complicated for processing the Ultra-WideBand （UWB） Synthetic Aperture Radar Interferometry （InSAR） data. To resolve this problem, a new approach is proposed in this paper. First, to acquire the high accuracy image registration result, the registration offsets are obtained from the interpolation of the offsets of the control points. Then, based on the offsets, the interferometric phase is computed and divided into two partsthe Registration Phase （RP） and the MisRegistration Phase （MRP）. The RP is derived from the registration offsets, and the MRP is dependent on the unknown misregistration. Theoretical derivations show that the MRPs are unambiguous in most high coherence areas, so MRP can be unwrapped efficiently, and its absolute phase can be obtained directly without using any auxiliary data. Finally, the absolute interferometric phase is obtained from adding the RP and the true MRP. Compared with the existing algorithms, the proposed approach has lower complexity. Experimental results on P-band UWB InSAR data prove its effectiveness.