Correlating OTS beacon measurements with radiometer and rainfall data

The equivalent media temperature (EMT) used in radiometer attenuation evaluations is treated. Measured attenuation and rain rate statistical distributions are used to check an equivalent distance model. For EMT, rain attenuation was measured for two beacon frequencies, using beacon signals, and calculated from radiometer values of antenna noise temperature increase using a fixed EMT value of 270 K. Reliable data are obtained. The 5 year average statistical distribution of attenuation can be estimated to within 5% from the 5 year average rain rate distribution for any 5 year period using the same equivalent distance curve (obtained from floating 5 year average distributions over a 7 year period). The error is within 0.5 db, even at the 10 db level.