The OMI Total Ozone Differential Optical Absorption Spectroscopy (DOAS) layer indicates the total ozone column and is measured in Dobson Units (DU). The Ozone Monitoring Instrument (OMI) Level-3 total ozone DOAS product (OMDOAO3e) product is one of two total ozone products provided by the OMI instrument and is calculated with the DOAS technique using a 5-nm spectral fitting window centered around 341 nm. The DOAS technique that has been widely used to measure trace gases from the ground. This ozone column is estimated from longer wavelengths than those used in the TOMS algorithm. In principle, DOAS is less sensitive to disturbing effects by absorbing aerosols, SO2, and calibration errors than the TOMS algorithm.

The OMDOA3e product provides daily gridded global coverage with a temporal resolution of 1 day, imagery resolution of 2 km, and a sensor/algorithm resolution of 0.25 x 0.25 degrees.

References: OMDOAO3e README; ATBD II; DOI: 10.5067/Aura/OMI/DATA3005; KNMI: Ozone