Comparing satellite rainfall estimates with rain gauge data: Optimal strategies suggested by a spectral model

摘要: [1] The statistical problem of comparing rain gauge measurements to satellite rain-rate estimates over an area surrounding the gauge(s) is examined using a model rainfall variability developed for studies sampling error in averages data. The able capture number important aspects space-time spectrum variability, including interdependence time and space scales variability. Four parameters must be specified model. Sets have been obtained that fit statistics radar-derived rates eastern tropical Atlantic (from GATE) western Pacific TOGA COARE). predicts there optimal averaging data when are compared average rain-rates around gauge. ranges from minutes days as diameter extended 2 km 200 km. shrinks more gauges added viewed by satellite, but suggests even fairly dense networks it necessary compare several hundred overflights order bring comparison down 10% level. possibility comparisons with might improved weighting differently depending on how close investigated, found some cases variance can reduced factor two time-dependent weighting.