Drift in the Meteosat-7 VIS channel calibration

This letter describes the methodology used to determine the drift in the slope and intercept value of the linear calibration coefficients of the Meteosat-7 visible sensor using the time series of data for clear-sky desert and sea areas. Statistical analysis between July 1998 and October 2001 using noon visible imagery was made. The results show that the offset of the calibration decreases throughout this period, also indicating a positive drift of about 1.9% per year in the slope of the calibration coefficient.