The OMPS Limb Profiler (LP) was launched on board the NASA Suomi National Polar-orbiting Partnership (SNPP) satellite in October 2011. OMPS-LP is a limb-scattering hyperspectral sensor that provides ozone profiling capability at 1.8 km vertical resolution from cloud top to 60 km altitude. The use of three parallel slits allows global coverage in approximately four days. We have recently completed a full reprocessing of all LP data products, designated as Release 2, that improves the accuracy and quality of these products. Level 1 gridded radiance (L1G) changes include intra-orbit and seasonal correction of variations in wavelength registration, revised static and intra-orbit tangent height adjustments, and simplified pixel selection from multiple images. Ozone profile retrieval changes include removal of the explicit aerosol correction, exclusion of channels contaminated by stratospheric OH emission, a revised instrument noise characterization, improved synthetic solar spectrum, improved pressure and temperature ancillary data, and a revised ozone climatology. Release 2 data products also include aerosol extinction coefficient profiles derived with the prelaunch retrieval algorithm. Our evaluation of OMPS LP Release 2 data quality is good. Zonal average ozone profile comparisons with Aura MLS data typically show good agreement, within 5-10% over the altitude range 20-50 km between 60°S and 60°N. The aerosol profiles agree well with concurrent satellite measurements such as CALIPSO and OSIRIS, and clearly detect exceptional events such as volcanic eruptions and the Chelyabinsk bolide in February 2013.
Following the successful launch of the Ozone Mapping and Profiler Suite (OMPS) aboard the Suomi National Polar-orbiting
Partnership (NPP) spacecraft, the NASA OMPS Limb team began an evaluation of sensor and data product
performance in relation to the original goals for this instrument. Does the sensor design work as well as expected, and
can limb scatter measurements by NPP OMPS and successor instruments form the basis for accurate long-term
monitoring of ozone vertical profiles? While this paper does not address the latter question, the answer to the former is a
qualified Yes given this early stage of the mission.
The performance of the OMPS/LP retrieval algorithm is assessed by conducting a series of numerical experiments and
evaluating the quality of the primary (ozone profile) and secondary products (aerosol profiles, NO2, cloud height, surface
reflectance) as well as height registration under a set of realistic atmospheric conditions selected randomly. The study
considers a number of orbits corresponding to Winter/Summer solstice and Spring/Autumn Equinox. It is shown that the
quality of the OMPS/LP retrieval products (accuracy, precision, vertical resolution, height registration) varies along the
orbit, as the single scattering angle transitions from backscatter to forward scatter and zenith angles vary from sunrise to
sunset. Instrument effects (straylight, gain consolidation, instrument noise) are also investigated. It is shown that ozone
profiles can be retrieved with an accuracy of 5% or better from the tropopause up to 50 km, a precision of about 3-5%
from 18 to 50 km, and a vertical resolution of 1.5-2 km. Stratospheric aerosol extinction profile can be retrieved with an
accuracy/precision of about 30%. The scene-based tangent height registration algorithm is shown to yield height
information with an RMS error of 250-300m.