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Integrated Cal/Val System for Microwave/Infrared/Radio Occultation
Small Satellite Sensors


In the era of increasing demand for timely and accurate Numerical Weather Predictions (NWP), miniaturization of satellite
components is making the use of small satellite (SmallSat) data in NWP increasingly more promising. Smallsat constellations
have distinct advantages: agile, cheaper, faster, smaller in comparison with legacy systems which takes decades to develop.
However, Smallsats also have disadvantages for operational weather forecast, including short lifespan, lack of consistency,
stability, calibration/validation, and data quality assurance.

There are two major areas of study in transitioning Smallsat from research to operations to assess its full utility for NOAAs Satellite Observing System Architecture (NSOSA):

  1. Data quality assurance in terms of spectral, radiometric, and geolocation accuracy through calibration/validation
    • Develop a framework for integrated calibration and validation of multi-sensor such as microwave (MW), infrared (IR)
      and radio occultation (RO) sensors on SmallSats.
    • Accommodate diverse sensor types with large data volume, and address challenge in cross-calibration of SmallSat sensors for applications in data assimilation for weather forecasting.
  2. Direct radiance assimilation into NWP (such as GFS)

This prototype webpage focused on addressing the initiative of developing a framework of integrated calibration/validation (Cal/Val) system (ICVS) among multiple and diverse sensors on SmallSat platform. Under the new paradigm of SmallSats such as low cost, more in quantity, large data volume and shorter lifespans, the framework enables rapid ingestion, calibration and validation of the
data with disparate cadence such as from microwave, infrared and radio occultation sensors on SmallSats. All of these SmallSats measure or retrieve atmospheric temperature and other profiles. A consortium of Cal/Val techniques such as SNO (Simultaneous
nadir Overpass) and colocation-based inter-sensor calibration, O-B (Model) radiometric bias evaluation, and inter-instrument (IR/
MW vs. RO) bias comparison through CRTM (Community Radiative Transfer Model) modelling have been developed, implemented and evaluated to address challenges in Cal/Val of SmallSat sensors. Using COSMIC-2 (RO) and TEMPEST-D (MW) SmallSat
sensors and legacy IR sensors as proxy SmallSat IR instrument, the framework of ICVS among multiple and diverse sensors on SmallSat platform is demonstrated on this webpage. This project is funded by the NOAA/NESDIS/OPPA Technology Maturity
Program (TMP 18-03)