Predicting near-time satellite signal attenuation at Ka-band using tropospheric weather forecast model

There are satellite communication applications where it is desirable to predict near time (e.g. 2 to 12 h) propagation losses at Ka-band due to hydrometeor precipitation. We present results from a project investigating the possibility and quality of short term prediction of satellite link attenuation at Ka-band. The starting point is a 67 h near time numerical weather prediction data from the Norwegian Meteorological Institute. A period of 3 months and for 3 sites in Norway have been studied. Based upon these accumulated 9 months of data, the precipitation along the satellite link to the ground terminal is calculated for every hour. The attenuation results from the model is compared to high accuracy contemporary measurements of the same path. If the forecast is predicting the presence of precipitation correctly, the predicted attenuation error has a low bias and the standard deviation value is typically in the order of 1.5 dB.