Atmospheric Effects on Ultra-High-Resolution Millimeter-Wave ISAR Imagery for Space Targets

In order to get more detail information about targets, ultra-high-resolution (UHR) millimeter-wave radar (MMW) is widely used. UHR MMW radar is sensitive to errors, and the atmosphere effect is one of the major factors affecting the final imaging quality during the exploring of space targets. In this paper, high-precision radar signal propagation models of the background troposphere and ionosphere are established. Based on the models, the influence mechanism of the atmospheric effect on radar signal echo is investigated. The simulation results show that the tropospheric effect lead to azimuth defocusing and a large shift in the range direction on the image. The ionospheric effect produces the intra-pulse phase error which is inversely proportional to frequency.