Advances in STAR Integrated Calibration/Validation System Long-Term Monitoring

The STAR Integrated Calibration/Validation (or CalVal) System (ICVS) Long-Term Monitoring (LTM) (hereinafter named as ICVS for clarity) has been running for a few years and its capability in terms of the number of POES and JPSS satellite instruments and the amount of instrument parameters being monitored have been significantly increasing over time. The instruments include but are not limited to Advanced Technology Microwave Sounder (ATMS), Cross-track Infrared Sounder (CrIS), Visible Infrared Imaging Radiometer Suite (VIIRS), Ozone Mapping and Profiler Suite (OMPS), and Advanced Microwave Sounding Unit-A. The monitoring parameters cover plenty of instrument-based Raw Data Record (RDR) and Sensor Data Record (SDR) parameters, e.g., on-orbit Noise Equivalent Differential Temperature (NEDT) or Radiance (NEdN), instrument calibration gain, calibration targets counts, calibration target temperature, instrument temperature, and a series of SDR data quality flags. The ICVS has successfully supported the operation of the number of POES and the SNPP mission. It is also playing a critical role for NOAA-20 instrument SDR CalVal and Environmental Data Record (EDR) products quality assurance. Therefore, the ICVS has become an important tool for satellite calibration scientists and data users within STAR and beyond for exploring and understanding data accuracy and instrument stabilities.

Recently, the monitoring of the ICVS has also been evolving from original RDR and SDR parameters to a number of more advanced products that are calculated based on SDR parameters and Numerical Weather Prediction (NWP) ancillary data and JCSDA Community Radiative Transfer Model (CRTM), e.g., inter-sensor comparison for Simultaneously Nadir Overpass (SNO) and non-SNO satellite-measured radiance or brightness temperatures, radiance or brightness temperature (O-B) biases between satellite observations and CRTM simulations, and double differences. The ICVS is experimentally monitoring the evolution of severe events such as hurricane and volcano by using different combinations of VIIRS RGB images and also 3D animation of ATMS and VIIRS images, where a 2D smoothing algorithm based on Discrete Cosine Transform (DCT) and Penalized Least Squares (PLS) is utilized to fill in the gap of the data. With those advances, the ICVS is expected to exhibit more innovative impacts on current SNPP/JPSS1 and future JPSS (J2 and J3) and Metop-C satellite missions for instrument stability and data quality monitoring.