A Four Channel Radiometer for Remote Sensing of Atmospheric Structure

摘要

The report describes a 4-channel radiometer system built to measure the intensity of microwave emission from atmospheric oxygen and water vapor. The 4 channels are at 22, 51, and 59 GHz. From such measurements, the profiles of humidity and temperature in the lowest 10 kilometers of the atmosphere may be inferred. Outputs from the 4 channels are recorded continuously. The system has internal calibration sources which are automatically switched to the radiometer inputs at regular intervals. External absolute calibration black bodies are available for periodic calibration of the internal sources. Considerable effort has gone into stabilizing the internal calibration and the radiometer operating frequencies. The operation and calibration of the instrument is discussed. (Author)