Summary

Description

The Level-1B (L1B) Radiance Product OML1BRUZ (Version-3) from the Aura-OMI is now available (http://disc.gsfc.nasa.gov/Aura/OMI/oml1bruz_v003.shtml) to public from the NASA GSFC Earth Sciences Data and Information Services Center (GES DISC). OMI calibrated and geolocated radiances for the channels in the UV1(264-311 nm), UV2 (307-383 nm) and VIS (349-504) regions, spectral irradiances, calibration measurements, and all derived geophysical atmospheric products are archived at the NASA Goddard DAAC. (The shortname for this OMI Level-1B Product is OML1BRUZ) The lead algorithm scientist for this product is Dr. Marcel Dobber from the KNMI. This Radiance product (OML1BRUZ) contains Zoom-in geolocated Earth view spectral radiances from the 557 UV2 detectors in the wavelength range of 307 to 383 nm. OMI performs spatial zoom measurements one day per month. In the spatial zoom-in mode the nadir ground pixel size is 13 x 12 km and measurements (30 pixels covering 750 km swath width) are available only for the UV2 (307-383 nm) and VIS (349-504) detectors. In the standard global measurement mode (covering 2600 km swath width), OMI observes 60 ground pixels (13 km x 24 km at nadir) across the swath for each of the 751 VIS (349-504 nm) channels and 557 UV2 (307-383 nm)channels, and 30 ground pixels (13 km x 48 km at nadir) for each of 159 channels of UV1 (264-311 nm). In addition, once a month in one orbit OMI performs dark measurements, it does not perform radiance measurements. OML1BRUZ 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. Each file contains data from the day lit portion of an orbit (~53 minutes) and is roughly 545 MB in size. There are approximately 15 orbits per day.