Effects of Span Length and Radar Polarimetry on the Backscattering Characteristics of Ultra-High Voltage Power Transmission Line in TerraSAR-X Images

摘要

With the continuous improvement of the spatial resolution of spaceborne synthetic aperture radar (SAR), detection of ultra-high voltage (UHV) power transmission line in high-resolution SAR images has become possible. However, the backscattering characteristics of UHV power transmission line in a SAR image are significantly influenced by several factors including the span length and the radar polarimetry. In this paper, the effects of span length and radar polarimetry on the backscattering characteristics of UHV power transmission line are analyzed by using the high-resolution TerraSAR-X images. We first give a brief introduction to the imaging geometry of UHV power transmission line. Subsequently, for different angles between the satellite ground track and the extend direction of power transmission line, the effect of span length on the scattering characteristics of power transmission line is described. In addition, the intensity and pixel size of scattering spots, which are formed by the power transmission line in the co-polarized SAR images, are analyzed. The analysis results show that the span length mainly influences the distance between the scattering spot and the perpendicular bisector of the power transmission lines. Moreover, the backscattering from the power transmission line can be found to be much stronger in the HH polarized SAR images compared with the VV polarized ones.