Microwave Radiometer for Cloud Carthography: A 22-channel ground-based microwave radiometer for atmospheric research

A 22-channel Microwave Radiometer for Cloud Carthography (MICCY) for the pr ofiling of tropospheric temperature, humidity, and cloud liquid water has b een developed. The radiometer has 10 channels along the high-frequency wing of the 22.235 GHz water vapor line, 10 channels along the low-frequency si de of the 60 GHz oxygen complex, and 2 channels at 90 GHz. Two features mak e the radiometer a unique tool for the observation of small-scale structure s related to cloud processes: (1) Atmospheric brightness temperatures are m easured simultaneously at all channels with an integration time of 1 s. (2) A Cassegrain system including a 90 cm off-axis parabolic mirror leads to a spatial resolution better than 1 degrees full width at half maximum for al l frequencies. The necessity of these features for cloud observations is de monstrated. Algorithms for the retrieval of integrated water vapor, integra ted cloud liquid water, and the profiles of temperature and humidity were d eveloped on the basis of artificial neural networks. Measurement examples, including comparisons with radiosondes, demonstrate the systems capabilitie s for high-resolution atmospheric monitoring.