A Continuously Tuned 53 - 59 GHz Radiometer for Measurement of Atmospheric Temperature Profiles

The design of a continuously tuned 53 - 59 GHz radiometer for measurement of the atmospheric temperature profile is presented. The broadband solution makes the radiometer cost-effective and permits observations on a large number of frequencies which increases the profiling accuracy. To meet the demand for high-precision measurements two calibration loads are included one of which is cooled to 253 K. During a field experiment the radiometer was calibrated and the absolute accuracy of the radiometer was found to be better than 0.5 K. The profiling capability was evaluated using the statistical inversion method. The accuracy of the retrieved profiles was improved when the number of channels was increased from four to eleven.