Microwave Radiometry in Remote Sensing

Microwave radiometry has shown its capabilities of observing and monitoring large-scale geophysical observables from space. Examples are sea surface temperature and surface wind over the ocean, sea ice extent, concentration and category and snow cover extent and water content. At low microwave frequencies the atmosphere is virtually transparent even with clouds which make microwave radiometry very valuable in regions with frequent cloud cover such as the temperate and arctic zones. At high frequencies, however, atmospheric absorption will degrade measurements of earth surfaces but this phenomenon proves useful for measurement of atmospheric parameters. Examples are detection of rain cells and frontal systems, temperature and humidity profiles and content of minor constituents in the atmosphere foremost above the troposphere. The above examples have been demonstrated from radiometer measurements from ballon, aircraft and spacecraft and it is expected that the next generation of spacecraft may encompass microwave radiometers in the frequency range from perhaps 1.4 GHz to 700 GHz taking advantage of a number of new developments. With the purpose of identifying the necessary developments an international workshop was organized in June 1982 with the object of reviewing the state-o-the-art in applications and techniques and to suggest future development work in data processing and application, systems principles and performance and in component development including the antenna system.