Summary

Description

The Level-1B (L1B) Radiance Product OML1BIRR (Version-3) from the Aura-OMI is now available (http://disc.gsfc.nasa.gov/Aura/OMI/oml1birr_v003.shtml) to public from the NASA GSFC Earth Sciences Data and Information Services Center (GES DISC). The Ozone Monitoring Instrument (OMI), an ultraviolet-visible imaging spectrometer was launched aboard the EOS-Aura satellite on July 15, 2004(1:38 pm equator crossing time, ascending mode). OMI with its 2600 km viewing swath width (60 cross track and about 1650 along track pixels) provides almost daily global coverage. OMI is a contribution of the Netherlands Space Office (NSO) in collaboration with Finish Meteorological Institute (FMI), to the US EOS-Aura Mission. The principal investigator's (Dr. Pieternel Levelt) institute is the KNMI (Royal Netherlands Meteorological Institute). OMI is designed to monitor stratospheric and tropospheric ozone, clouds, aerosols and smoke from biomass burning, SO2 from volcanic eruptions, and key tropospheric pollutants (HCHO and NO2) and ozone depleting gases (OClO and BrO). (The shortname for this OMI Level-1B Product is OML1BIRR) The lead algorithm scientists for this product is Dr. Marcel Dobber from the KNMI. OMI calibrated and geolocated radiances for the UV and Visible channels, spectral irradiances, calibration measurements, and all derived geophysical atmospheric products are archived at the NASA Goddard DAAC. The OMI Level 1B Solar Irradiance Product OML1BIRR contains spectral measurements of the solar irradiances from UV1 (264-311 nm; 159 channels), UV2 (307-383 nm, 557 channels) and VIS (349-504 nm,751 channels) detectors. OMI makes solar irradiance measurements indirectly using a diffuser. Each solar observation consists of multiple measurements at different solar elevation angles. This product provides average of the individual measurements made along track to average out the solar elevation dependent BRDF features of the diffuser. OML1BIRR files are stored in EOS Hierarchical Data Format (HDF-EOS 2.4) which is based on HDF4. The radiance for the earth measurements (also referred as signal) and its precision are stored as a 16 bit mantissa and an 8-bit exponent. The signal can be computed using the equation: signal = signal_mantissa x 10 exponent . For the precision, the same exponent is used as for the signal.