DOAS retrievals on satellite data
Although the DOAS technique was developed to analyse ground-based zenith-sky and active long-path measurements, it can also be applied to satellite borne measurements in the UV and visible, if they provide enough spectral resolution to make use of the differential part of the absorptions.
The GOME and SCIAMACHY instruments were designed to provide such information, and column amounts for many species including O3, NO2, BrO, OClO, HCHO, SO2 and H2O could be derived from these measurements using the DOAS technique.
Of particular interest is the ability of GOME and SCIAMACHY to determine tropospheric columns of some species, e.g. NO2, HCHO, SO2, and BrO. These unique measurements provide a wealth of information on tropospheric chemistry in general and pollution in particular.
For strong absorbers and the IR spectral region, variants of the DOAS technique are employed to account for the effects of line saturation and nonlinearities. More on these retrievals can be found on the AMC-DOAS page for H2O and on the WFM DOAS pages for CO, CO2, and CH4.