Prelaunch spectral calibration of a carbon dioxide spectrometer

The carbon dioxide spectrometer (CDS) on board the Chinese Carbon Dioxide Observation Satellite (TanSat) is a high spectral and spatial resolution grating spectrometer with three specific spectral bands dedicated to atmospheric CO2 detection. The CDS's design and on-ground spectral calibration are presented in this paper. The instrument line shape functions and spectral dispersion were characterized using a tunable diode laser-based testing system for all spectral pixels of the CDS placed in a thermal vacuum chamber.