Numerical Simulation of the Radar Cross Section of UHV/EHV Power Lines Illuminated by X-, C-, L-, and P-Band Spaceborne SAR

Many spaceborne synthetic aperture radars (SARs), which operate separately in the X-, C-, and L-bands, have been employed to monitor ultra-high-voltage (UHV) and extra-high-voltage (EHV) power lines. However, a full interpretation of the scattering characteristics of these power lines in spaceborne SAR images remains a challenging task. A numerical simulation of the radar cross Section (RCS) of UHV/EHV power lines in the X-, C-, L-, and P-bands over a wide range of incidence angles is presented in this article. A physical model of the UHV/EHV power line is first built. Here, two practical shapes of the UHV/EHV power line are considered, which include the symmetrical catenary when two suspension points have the same height and the inclined catenary when the heights of two suspension points are different. Then, the multilevel fast multipole algorithm (MLFMA) is used for the analysis of the backscatter behavior of UHV/EHV power lines in the X-, C-, L-, and P-bands. The effects of several parameters of practical importance on the backscatter RCS of UHV/EHV power lines are also studied, which include the carrier frequency, polarization type, aspect angle of illumination, span length, height difference between two suspension points, conductor sag, and cable diameter. In addition, several comparisons made between simulated and practical observation results demonstrate that the obtained theoretical results can be used to interpret the scattering characteristics of UHV/EHV power lines in spaceborne SAR images and can provide some useful suggestions for monitoring UHV/EHV power lines using spaceborne SAR images.