Inversion of data from diffraction-limited multiwavelength remote sensors 3. Scanning multichannel microwave radiometer data

A spatial filtering algorithm is described, by means of which geophysical parameters are retrieved from measurements made over the ocean by the scanning multichannel microwave radiometer on the Nimbus 7 satellite. The parameters are near-surface wind speed, sea surface temperature, rain rate, integrated atmospheric water vapor content, and integrated liquid water content (including rain). The capabilities and limitations of the algorithm are demonstrated with data obtained from a tropical cyclone which occurred in the Indian Ocean in November 1978 and with data from the North Atlantic. The major limiting factor, away from land, is the high opacity of the atmosphere in areas of heavy rain, particularly with respect to retrieval of surface temperature and water vapor. However, despite the presence of rain the wind speed retrieval locates the cyclone and provides a measure of its intensity.