Imap Doas

D-81519 OCO-2 Algorithm Theoretical Basis Document IMAP-DOAS preprocessor

Iterative maximum a posteriori (IMAP)-DOAS for retrieval of strongly absorbing trace gases: Model studies for CH4 and CO2 retrieval from near infrared spectra of SCIAMACHY onboard ENVISAT

In the past, differential optical absorption spectroscopy (DOAS) has mostly been employed for atmospheric trace gas retrieval in the UV/Vis spectral region. New spectrometers such as SCIAMACHY onboard ENVISAT also provide near infrared channels and thus allow for the detection of greenhouse gases like CH4, CO2, or N2O. However, modifications of the classical DOAS algorithm are necessary to acco...

Retrieval techniques for airborne imaging of methane concentrations using high spatial and moderate spectral resolution: application to AVIRIS

Two quantitative retrieval techniques were evaluated to estimate methane (CH4) enhancement in concentrated plumes using high spatial and moderate spectral resolution data from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). An iterative maximum a posteriori differential optical absorption spectroscopy (IMAP-DOAS) algorithm performed well for an ocean scene containing natural CH4 em...

Retrieval of CO from SCIAMACHY onboard ENVISAT: detection of strongly polluted areas and seasonal patterns in global CO abundances

SCIAMACHY onboard the European environmental research satellite ENVISAT is an UV/visible/nearinfrared spectrometer providing 3 near infrared channels covering wavelengths from 1–1.75μm, 1.94–2.04μm and 2.26– 2.38μm with moderate spectral resolution (0.22–1.5 nm). From their structured absorption in these spectral regions, we can quantitatively determine the total column densities of the greenho...

Retrieval of Co from Sciamachy Onboard Envisat

SCIAMACHY onboard the environmental research satellite ENVISAT is a UV/visible/near-infrared grating spectrometer providing 3 near infrared channels covering wavelengths from 1-1.75μm, 1.94-2.04μm and 2.262.38μm with moderate spectral resolution (0.22-1.5nm) (Bovensmann et al. 1999). Among the absorbers in these regions are the greenhouse gases CO2, CH4, N2O and H2O as well as CO. A modified DO...