A method for detecting red tides using AVHRR imagery

The Advanced Very High Resolution Radiometer (AVHRR) on board the TIROS-N/NOAA series of operational meteorological satellites has both visible and thermal infrared channels, which enable sea-surface temperatures (SSTs) and other parameters related to water quality to be derived. A method has been developed for the detection of red tides using all the AVHRR channels. It employs neural networks. The detection of red tides is based on the fact that (1) the seawater has higher concentration of phytoplankton pigments when red tides occur and (2) the occurrence of red tides is associated with sea surface temperature. The method has been tested. An example is presented.