The Ozone Monitoring Instrument (OMI) is a wide-angle, nadir-viewing push-broom spectrometer with UV and visible light CCD detectors. With 780 spectral pixels and 576 spatial pixels, OMI measures spectral solar irradiance and backscattered radiance from the Earth at near-UV/visible wavelengths of 264–504 nm (nanometers) with a spectral resolution between 0.42 nm and 0.63 nm. The telescope field-of-view is 114º wide, providing a swath of 2600 km with ground footprint of 13×24 km² at nadir.

OMI products include spectral solar irradiance, ozone (O₃) stratospheric and tropospheric columns and profile, column amounts of short-lived reactive trace gases (nitrogen dioxide (NO₂), anthropogenic and volcanic sulfur dioxide (SO₂), bromine monoxide (BrO), formaldehyde (HCHO), chlorine dioxide (OClO), and Glyoxal (CHOCHO) ), optical centroid cloud pressure and effective cloud fraction, aerosol optical properties in UV, and surface and underwater UV irradiance (erythemal UV Index).

OMI is a contribution of Netherlands Agency for Aerospace Programmes (NIVR), in collaboration with the Finnish Meteorological Institute (FMI), to NASA's Aura mission, which was launched in 2004. The Dutch industrial efforts focused on the optical bench design and assembly, thermal design, and project management by the Royal Dutch Meteorological Institute (Koninklijk Nederlands Meteorologisch Instituut, KNMI). The detector modules and the readout and control electronics were provided by Finnish industrial partners. Data processing is a joint effort between the U.S. OMI Science Team and the KNMI OMI Team.

In 2007, OMI radiance measurements from the Earth-view port began to develop unexpected errors at some view angles (cross-track positions). The issue is called the “row anomaly” because the OMI radiance spectra collected at different view angles are imaged onto rows of the CCD detectors. Excluding anomalous rows, essentially complete global coverage is currently achieved in two days. OMI solar irradiance measurements are not directly affected by this issue.

Learn more about near real-time OMI data provided by NASA's Land, Atmosphere Near real-time Capability for Earth observation (LANCE).