Detection and mitigation of interference in the calibration of high gain antennas for GNSS

In the field of Global Navigation Satellite System (GNSS) a robust and dependable navigation is one of the most challenging task for modern space missions. To accomplish this purpose, DLR uses the high gain ground antenna, a 30 meter dish located in Weilheim. The calibration of the big antenna is performed using the radio sources emission, such as Cassiopea-A, Taurus-A, or Cygnus-A This method has been used by radio astronomers for years, but it shows some impairments when the link is obstructed by the presence of interference. Therefore, the estimation of the final gain of the antenna may be affected by some errors. The aim of this paper is to present a post processing algorithm, which detects the corrupted frequencies, and later on mitigates the effect of the interference. The gain estimation is compared before and after the application of the algorithm, showing some improvements in correspondence of the interference occurrence.