Dynamic Range Improvements for Beacon Receivers Using Noise Power Measurements

Satellite beacon receivers are metrology instruments measuring beacon power to determine excess tropospheric attenuation. In the presence of thermal noise, beacon power measurements are biased and should be corrected a posteriori using unbiased (or with minimum bias) estimators to remove or at least to reduce the noise contribution. When satellite beacon receivers are able to measure the noise power level in a frequency band adjacent to the beacon frequency band, it is shown that this additional information can be used opportunely to reduce the estimation bias. In this context, three estimators are discussed, one of which is an originality introduced to take into account the particular processing of beacon measurements. The performances of these estimators are assessed using synthetic time series simulating beacon measurements. For the new estimator, the results show a dynamic range improvement of about 12 dB, using typical beacon receiver characteristics. When considering long-term statistics of attenuation, the improvement is even larger. The estimators are applied to experimental beacon receiver data collected in Ka and Q bands in Toulouse (France). The results confirm the potentiality of the approach to improve significantly the dynamic range of beacon measurements.