The Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) is one of the ten instruments onboard the Envisat satellite launched from Kourou (French Guyana) on the 28th of February 2002 and operated by the European Space Agency (ESA) until May 2012. SCIAMACHY measures transmitted, backscattered and reflected radiances from the atmosphere at high resolution (240 to 1700 nm, 2 microns and 2.4 microns). The instrument makes limb and nadir observations that can be combined. Its main objective is to provide global measurements of trace gases in the troposphere and the stratosphere.

The data issued by ESA include Level 1B (radiances) and Level 2 (derived quantities) products. They come in a number of versions: a near real time (nrt) version, a consolidated version, result of a first processing by ESA to eliminate bad data and perform a few basic checks, and fully reprocessed versions.