The status of the passive microwave sensing of the waters - Lakes, seas, and oceans - Under the variation of their state, temperature, and mineralization (salinity): Models, experiments, examples of application

This paper discusses remote sensing (RS) of the major types of water bodies by means of microwave radiometry. The analysis is based on theoretical models and experimental data taken under laboratory conditions, in a pool, from a shore, and over the oceans using aircraft and satellites. The radiation is found to depend on wind speed and the geometry of ripples, gravity waves, swell, foam, and some physical and chemical parameters of water such as its temperature, salinity, and concentration of some types of polutants. The estimates of the effectiveness of the microwave radiometric method for determining the above mentioned water-surface parameters are given. Examples of the application of microwave radiometry to obtaining operational information about some of them are also presented. The types of water observed are the inland waters, fresh or with a high concentration of salts, clean or polluted, and the oceans. The paper is based on the theoretical and experimental investigations conducted by the author and his colleagues at the Institute of Radio Engineering and Electronics of the Academy of Sciences in the USSR over the last 20 years. It also draws upon well-known Soviet and foreign publications.