The application calculates the supit constants for all weather stations in table WEATHER_STATION and updates/inserts only the differences in the SUPIT_CONSTANTS table. The interpolation is validated for the European region. Therefore the calculated constants of faraway stations must be treated with care. Whenever a new weather station is added, the tables SUPIT_CONSTANTS, CALCULATED_WEATHER and REFERENCE_WEATHER should be re-calculated (in this order). Before reprocessing interpolated GRID_WEATHER archive also the table WEATHER_DATA_AVAILABILITY should be recalculated.