The influence of the atmosphere on microwave radiometric measurements in the 10 GHz to 400 GHz frequency range

The influence of the atmosphere on the brightness temperature of ground based objects, the reflectivities of which are known, is discussed. Attenuation caused by atmospheric gases and hydrometeors (rain, fog, clouds, snow) is described in detail. Given this attenuation, a computer program for the radiometric transfer equation was compiled. The possibility of determining the brightness temperature for any object on the ground and for any position of the sensor is shown. The brightness temperature was computed for 38 different frequencies in the range of 10 GHz to 400 GHz, for two viewing angles (zero and 60 deg), for six different heights of the sensor between 100 and 8000 m, for 19 different weather conditions, and for 41 different reflectivities of objects. The results are presented as diagrams.