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The Ozone Mapping and Profiler Suite (OMPS) aboard the Joint Polar Satellite System-1 (JPSS-1) spacecraft is the 2nd Ultraviolet (UV) Sensor Suite launched on November 18, 2017. Similar to the OMPS on S-NPP, the OMPS on JPSS-1 (which is also named NOAA-20, or N20) contains two advanced nadir viewing hyper-spectral instruments, Nadir Profiler (NP) and Nadir Mapper (NM), to measure the total column and vertical profile of ozone in the atmosphere globally. This paper first briefly summarizes the status of calibration to OMPS on N20 sensor data record (SDR) at NOAA, which reached provisional maturity status on April, 2019 but more update on the stray light correction is on-going. An initial assessment of NOAA N20 SDR products are present in this paper. In these validations, we first compared the NP and NM spectral from N20 with the collocated spectral from S-NPP and TROPOMI. In addition, the radiative transfer model, TOMRAD, was used to simulate the radiance to be measured by OMPS NP and NM, and the inputs include the collocated ozone profiles from S-NPP and the total ozone amounts from either S-NPP or TROPOMI. Both simulations and spectral comparison with S-SNPP show that most channels meet the requirements with an accuracy of 2%, except in channels where the impact by stray light is large. However, the normalized reflectance of N20 is, on average, 10-30% smaller than TROPOMI. Due to the large spatial and spectral solution between OMPS and TROPOMI, further comparison by selecting the clear cases is needed. Results of this study provide useful information on NOAA-20 OMPS post-launch calibration assessment and preliminary analysis of its calibration stability and consistency with S-NPP. These two approaches through (1) the crosscomparison of spectral, and (2) the comparison with simulations, will be used to monitor the status of OMPS and improve the N20 OMPS radiance calibration at NOAA.
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