Data Quality and Validation of Satellite Measurements of Tropospheric Composition

Abstract

Validation is the essential part of satellite remote sensing, since the retrieved data must be fit-for-purpose and their significance quantified, whether they are for scientific research or environmental monitoring. Data are validated by comparing satellite data sets with those obtained from ground-based, balloon and airborne instrumentation, or from instruments on other satellites, or with the output of models; all can be fraught with sampling difficulties and comparability. Chapter 7 discusses these problems in some detail and indicates the quality assurance that is used in the field. The possibilities of optimising retrieval algorithms are dealt with, as well the problem of instrument degradation over time. The differing needs for data on trace gases and cloud and aerosol data are mentioned, as are the use of correlative methods. The chapter concludes with requirements for future measurements and possible validation strategies.