Summary: | In this paper, the response of 7 Earth observation satellite sensors from multiple platforms, as well as different sensors on the same platform, are cross-compared over the Dome C plateau, Antarctica, during the austral summer of 2008-2009. A single, unified methodology is employed to remove geometric, temporal and atmospheric biases between different sensors with a range of spatial resolutions, bandwidths and overpass times. The result assumes no “correct” baseline value, only relative responses. The method is derived from an in-depth sensitivity analysis, presented elsewhere [1], [2], that takes into account: BRDF effect, cloud cover, macro-scale hoar-frost change and variations in atmospheric pressure, temperature and composition, including water vapour, ozone and aerosol content variation with altitude. The resulting responses of the sensors: AATSR, AVNIR-2, ETM+ (Landsat 7), MERIS, NigeriaSat-1, VEGETATION 2 and UK-DMC-1 are presented, and where overlap occurs, compared with the results from other groups [3], [4], [5]. In addition to introducing the QA4EO protocols for the quality assurance of environmental monitoring satellites, this paper also discusses several sensors used to establish the technical basis of the ESA GlobAlbedo project: an open access, validated, 15 year long record of broadband land surface albedo (both snow and snow-free) from European sensors alone [6].
|