VERIFICATION OF MERIS ATMOSPHERIC LEVEL 2 PRODUCTS: INTEGRATEDWATER VAPOUR ABOVE LAND, OCEAN AND CLOUDS

摘要

Three different algorithms for the remote sensing of atmospherical water vapour above cloud free land surfaces, cloud freernocean and clouds were developed for the MERIS instrument. During the commissioning phase, two subsequent tests had tornbe performed: In a first verification step, the general nature of the results had to be investigated in order to detect problemsrnin the implementation of the algorithms in the IPF. For that purpose, a comparison of the MERIS results with independentrnwater vapour measurements from the MODIS instrument onboard the Terra platform was performed for different sitesrncovering different geographic and climatic regions. In the second validation step, a quantitative analysis of the accuracy ofrnthe retrieved water vapour values was started by the mean of comparisons with radio soundings. For the latter, MERISrnmeasurements taken during October 2002 above selected sites in central Europe were used.