An estimation of atmospheric attenuation on an earth-space radio link operating at Ka-band over Larsemann hills area of Antarctica

Abstract

The National Remote Sensing Centre (NRSC) has established its ground station named Antarctica Ground Station for Earth Observation Satellites (AGEOS) at Bharati station located at Larsemann hills area of Antarctica for the tracking and data acquisition from polar orbiting satellites. A communication link through a geostationary satellite in C-band is being used for transferring data to the mainland. There is a need to enhance the data rate in the near future considering the huge volume of data being acquired at AGEOS. A satellite link operating at Ka-band is proposed for accommodating the bandwidth requirements. It is necessary to estimate the worst case atmospheric attenuation at Ka-band over Larsemann hills area for calculating the link margins required. The India Meteorological Department (IMD) has setup a wide range of meteorological instruments at Bharati station and the local data collected for the years 2020, 2021 and 2022 are used in this study. The link is assumed to operate at a frequency of 20 GHz with linear polarization. An exceedance probability of 0.1% is used to arrive at the annual statistics of the attenuation. Recommendations by the International Telecommunication Union (ITU) are followed and the estimation is carried out using MATLAB. An estimated total atmospheric attenuation of 2.28 dB is obtained. The results are used further for carrying out link budgeting for a Ka-band satellite communication link between Bharati station and India.