Locating RFI Source by Integrating Ascending and Descending Passes Based on SAR Raw Data

The existence of radio frequency interference (RFI) significantly affects the quality of synthetic aperture radar (SAR) images. Locating RFI source serves as a component of electromagnetic situational awareness, which provides preliminary information for intelligent anti-interference. In this article, an RFI source localization method was proposed. Specifically, the SAR raw data both in ascending and descending passes were integrated to obtain the localization information of RFI. The localization index (LI) was first proposed to locate the RFI source after RFI detection and extraction. Subsequently, the location of the RFI source is determined by referring to the LI and the orbit inclination of the satellite-borne SAR based on radiation pattern weighing (RPW) in azimuth. Finally, the localization accuracy of the proposed method in both side-looking and squint situations is verified through simulation experiments. Based on the SAR level-0 raw data of sentinel-1 in Dubai and Jinan, the localization results show that the RFI source are near the city center or the airport. It provides a high-precision and convenient RFI source localization solution for anti-interference as well as monitoring RFI, and theoretical analyses indicate significant improvements in localization accuracy compared to the traditional X-mark method.