Optimizing X and Ka band data volume return for BepiColombo mission using Cebreros and Malargue data and weather-forecast based methodology

The optimization of the received data volume is one of the key objectives of deep-space missions. Recently, the Ka-band is being investigated for its possible employment as complementary channel of X-band that, to date, is one of the more diffuse for deep-space transmissions. In this context, Bepi Colombo (the ESA mission to Mercury planned in 2018) foresees both an X-band and a Ka-band channel for the transmission of the scientific data. For microwave frequencies above the X band, the troposphere impairments on the propagating signal represent a limitation to overcome. New emerging prediction techniques based on weather forecast and radio meteorological models, can be usefully adopted to optimize Ka-band transmission data rates (and maximize the received data volume) with respect to the forecasted channel state. We have recently demonstrated this concept for the Cebreros (Spain) ESA-Track station within Bepi Colombo mission for the sample year 2012. In this work we spatially and temporally extend the previous data volume analysis made for Cebreros in a more systematic way by considering a longer transmission period up to 4 years for both the ESA-track stations in Cebreros and Malargüe (Argentina) at X and Ka band. WE have tested the output of the radio meteorological forecast model for both Cebreros and Malargue sites using available measured data. In addition, for Cebreros station, we have exploited ground-based microwave multi spectral radiometric measurements to make more robust validation of our model outputs. Preliminary results show that the use of weather-forecasts for the optimization of received data volume brings some improvements even though further analyses are needed before adopting this procedure as a pre-operational prototype for deep space missions.