title: Calibration monitoring of the visible and near-infrared channels of the along-track scanning radiometer-2 by use of stable terrestrial sites.
abstract: The Along-Track Scanning Radiometer-2 (ATSR-2) is equipped with visible and near-infrared channels at 1.6, 0.87, 0.66, and 0.56 microm. An in-flight visible calibration (VISCAL) system used to convert the raw signal to top-of-the-atmosphere reflectances is described. To monitor the long-term stability of the VISCAL, a number of large-area stable terrestrial sites have been employed. We describe the methods used to determine the long-term drifts in the ATSR-2 onboard calibration device and evaluate the suitability of the sites for calibration monitoring.
authors.affiliation: Rutherford Appleton Laboratory, Council for the Central Laboratory of the Research Councils, Didcot, Oxfordshire, United Kingdom. d.l.smith@rl.ac.uk
authors.forename: Dave L
authors.initials: DL
authors.lastname: Smith
authors.forename: Chris T
authors.initials: CT
authors.lastname: Mutlow
authors.forename: Rao C R
authors.initials: RC
authors.lastname: Nagaraja