Height Profile Estimation of Power Lines Based on Two-Dimensional CSAR Imagery

In circular synthetic aperture radar (CSAR) mode, a 2-D image contains 3-D spatial information about the imaged targets. This letter describes an attempt to estimate the height profiles of power lines with slightly varying heights based on 2-D CSAR imagery. First, according to the characteristics of a 2-D CSAR image of a power line with constant height, an approximate formula is deduced to calculate the height of the power line. This formula can also be used to calculate the height of several power lines with the same constant height. Second, a three-step processing method is proposed for height profile estimation of power lines with slightly varying heights. The first step is to extract regions of power lines automatically. The second step is to obtain the initial heights of the power lines according to the deduced approximate formula. The third step is to estimate the final height profiles of the power lines. Finally, experimental results have shown that 2-D imaging results of power lines with slightly varying heights are well focused when the height profiles estimated by the proposed three-step method are used.