Documentation and evaluation of the CSE NOAA AVHRR data set |
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| Authors: | Gorm Dybkjær Thomas Theis Nielsen Kjeld Rasmussen Michael Schultz Rasmussen Lars Boye Hansen Assize Touré |
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| Institution: | 1. Danish Meteorological Institute, Development Division , Lyngbyvej 100, 2100 , Copenhague O , Denmark E-mail: gd@dmi.dk;2. Institute of Geography, University of Copenhagen , ?ster Voldgade 10, DK-1350 , Copenhagen K. , Denmark E-mail: ttn@geogr.ku.dk kr@geogr.ku.dk msr@geogr.ku.dk lbli@geogr.ku.dk;3. Centre de Suivi Ecologique (CSE) , BP 15532, Dakar , Fann , Senegal E-mail: assize@cse.sn |
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| Abstract: | A NOAA AVHRR data set covering Senegal and parts of the surrounding countries during the period from 1987 to present is under construction and improvement in an ongoing collaboration between Centre de Suivi Écologique (CSE). Dakar. Senegal, and Institute of Geography, University of Copenhagen (IGUC). This paper details the entire processing chain from raw images to a properly calibrated, geometrically rectified and cloud-masked time-series tracking a number of well-defined variables. Two vital aspects of this time series, the cloud masking procedure and the geometrical rectification, are evaluated in detail. A two-step, multi-criteria cloud masking procedure requiring a manual input does not consistently improve the quality of the data set compared to the simpler, automated procedure. With respect to geometrical rectification an accuracy on the order of I km is obtained. Finally, suggestions for further improving the data set are forwarded |
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| Keywords: | NOAA AVHRR Senegal time-series environmental monitoring |
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