Impact of cross‐polarization isolation on polarimetric target decomposition and target detection

Abstract

Cross-polarization isolation is one of the key engineering parameters for a polarimetric radar system. Previous studies focused more on the calibration of cross-talk contamination. This paper presents a numerical evaluation of the requirement for cross-polarization isolation from the data users' perspective, i.e., the quantitative impact of polarization cross talk on polarimetric target decomposition and the associated applications such as classification and detection. Sensitivity analyses of several commonly used target decomposition parameters suggest that a theoretical lower bound of À32 dB isolation level is preferred to avoid any significant impact on these parameters. Our analyses with both simulated and real synthetic aperture radar (SAR) data show that a level of À25 dB would be acceptable for general terrain surface classification. This requirement is also true for man-made target detection application. Using simulated SAR images of man-made targets in natural environment, sensitivity analyses on two polarimetric detectors, Yang and Marino, both suggest that target detection performance would break down rapidly if isolation deteriorates from À25 dB to À20 dB.

Polarimetric Calibration and Quality Assessment of the GF-3 Satellite Images

“…The crosstalk error increases the magnitude of the cross-pol images relatively, and the target will be more likely to display volume scattering properties. Most PolSAR applications require that the crosstalk should be less than −32 dB [ 18 ]. Meanwhile, for geophysical parameter inversion research and multitemporal studies over large areas, a higher accuracy is needed, and the crosstalk should be less than −35 dB [ 19 , 20 , 21 ].…”

Depolarization Characteristics of Different Reflective Interfaces Indicated by Indices of Polarimetric Purity (IPPs)

“…When light interacts with targets, the polarization of the incident light may undergo a modification, carrying structural information of the targets. Therefore, it is important to characterize the process of the reflective polarization for exploring the polarization distributions and revealing the features of the surface, which can be used in polarization remote sensing [ 9 , 10 ], target detection and recognition [ 11 , 12 , 13 , 14 ], especially in the hidden-target identification. When the sample is not an ideal smooth surface, the reflected light will have different propagating directions, namely scattering.…”

Impact of Polarization Distortions on Geometrical Structure Retrieval of Moving Man-Made Targets in ISAR Images

“…With respect to evaluating the impact of various distortions on polarimetric parameters from the perspective of applications, there are some studies in the literature [15][16][17] that have focused on the field of terrain surface classification; Wang Y defined the maximum normalized error (MNE) as a generic metric to bridge the system polarization distortion and the polarimetric measurement quality [15]. Guo S [16] then used the MNE to assess the influence of polarization distortion on H/α decomposition.…”

“…Therefore, the MNE cannot be directly used in the field of GSR. Another method [17] evaluates the impact of crosstalk contamination by the first-order derivatives of two Cameron parameters of terrain surface classification and man-made target detection. The study suggested that a crosstalk level of −25 dB would be acceptable for these chosen applications.…”

“…However, in a practical system, the crosstalk distortion is only one of the measurement errors. Meanwhile, because of the impact of these errors on targets and applications, we cannot simply apply the conclusion in [17] to GSR of man-made targets. This is the primary motivation of this study.…”