Target area base d relational dat abase system for managing earth observation info rmation

Monitoring of environment requires several sources of information to be combined: "General knowledge" of the monitored area, measurement information on it and naturally previously made assessments of the same area. To use earth observation in monitoring of for example lake water quality, traditional images have limited value: How could they be used for example when one wishes to draw a graph of time series from several lakes in order to compare them? Indicator values stored in a database would be required. To solve these data use problems in water quality monitoring, ULAPPA system was developed using target area approach. It starts from the fact that usually the areas to be m onitored a re c learly d efined: L akes, f ields e tc. h ave more or less well­defined locations and boundaries. They have distinctive a priori characteristics as individual entities or according to their type, in situ measurements are made on them, they are being observed by several types of satellites and all this data is combined using several different algorithms, possibly with several versions of algorithm parameters. Sometimes model assimilation requires access to uninterpreted, usable satellite data. Management of usable earth observation data is critical for optical data, as clouds often obscure the target area. All these needs can be integrate d according to u ser needs using the target area approach.