High elevation satellite interference source localization based on joint time-frequency difference analysis

With the widespread use of space satellites, radio astronomical telescopes are increasingly affected by high elevation interference. Further determining the frequency, position, and distribution of satellite interference sources in the entire sky is an important means of effectively planning astronomical observations. A method for locating high elevation satellite interference source is introduced in this article based on time-frequency difference. Based on time-frequency difference information, the problem of joint estimation and positioning of interference source is deconstructed. Firstly, a ground received signal model for time-frequency difference joint estimation is established. Based on second-order cross-correlation and fourth-order maximum likelihood methods, time difference of arrival (TDOA) and frequency difference of arrival (FDOA) are estimated jointly. The interference source localization scenario and model are established, and the interference source is located using a two-step weighted least squares algorithm. After simulation verification, the positioning and trajectory estimation of high elevation fast motion interference source are achieved, and the minimum positioning error for interference source at a height of 300 km can reach 78 m. The use of satellite interference source positioning algorithm based on joint time-frequency difference analysis for radio observatory site radio environment measurement may improve the scientific output and ensure stable operation of radio telescopes.