The Sardinia Radio Telescope Upgrade to Telemetry, Tracking and Command: Beam Squint and Electromagnetic Compatibility Design

This paper describes the most recent improvements for the upcoming upgrade to telemetry, tracking and command (TT&C) capabilities for the Sardinia Radio Telescope (SRT), a 64-m antenna tailored for radio-astronomical observations of cosmic radio sources located in the outer space. Due to the TT&C improvement, the SRT will represent one of the Europe´s main establishments for the support of present and future deep space missions. The first part of this paper is dedicated to the Gaussian Beam synthesis of the SRT feeding system, called beam waveguide, fashioned to maximize the antenna illumination and spillover efficiency. The best design parameters have been retrieved through a rapid and efficient optimization analysis and verified by means of physical optics simulations. In accordance with the obtained results from the Gaussian formulation, further in-depth studies have been undertaken in order to investigate a technique able to overcome the so-called beam squint issue, a typical drawback that occurs during the tracking process of active spacecrafts. The proposed approach manages to automatically attain and quickly the best antenna beam steering strategy to correct the squint issue by means of a field-matching algorithm. Finally, this paper reports the analyses developed for electromagnetic hazard predictions, which shall be carefully taken into consideration for the safety of personnel working close to the high-power radiating installations and for preventing the astronomical receivers located near the Prime and the Gregorian foci from being damaged when the antenna is transmitting.