Precipitation measurement by satellites: Towards community algorithms

Abstract Almost 25 years have elapsed since satellite data were used first in attempts to estimate rainfall. Many techniques have been proposed and tested for this purpose since then, based on visible, and/or infrared, and/or passive microwave data. Largely because of the difficulty of intercomparing results from different regions and over different periods of time many different techniques have been developed which are of potential value for “operational” use in support of pure and applied hydrology. However, several algorithm intercomparison projects based on common data sets are now being undertaken, or are being planned. Their results will open the way for much-needed “community algorithm” selection and/or development. This paper summarises the need for satellite measurements of precipitation, reviews approaches adopted in satellite rainfall monitoring, considers significant recent advances in satellite rainfall monitoring algorithm design and development, and introduces the more important algorithm intercomparison projects. It concludes with a suggested scenario for rainfall monitoring across a wide range of scales, deploying different data types and selected types of satellite algorithms.