Advanced-TOVS (ATOVS) sounding products from NOAA operational polar orbiting satellites

The National Oceanic and Atmospheric Administration currently deploys a fleet of civilian, polar orbiting environmental satellites which provide users and researchers with a complete suite of operational, atmospheric and environmental data. On May 13, 1998, the first in a series of Advanced TIROS Operational Vertical Sounder (ATOVS) instrument configurations was successfully deployed into an evening (1930 LST, ascending) orbit onboard NOAA-15. This was followed by NOAA-16, an afternoon (1330 LST, ascending) satellite deployed in October, 2000, and NOAA-17, a late afternoon (1630 LST, ascending) satellite deployed in June, 2002. The ATOVS instrument configuration consists of the 15-channel Advanced Microwave Sounding Unit-A (AMSU-A), the 5-channel AMSU-B, the 20-channel High-resolution Infrared Radiation Sounder (HIRS/3), and the 5-channel Advanced Very High Resolution Radiometer (AVHRR).

The following report summarizes the current scientific algorithms for ATOVS operational temperature and moisture soundings and clouds. Topics include the requirements for ground truth (i.e., radiosonde) observations concurrent with each satellite in product monitoring, processing, validation, and subsequent user applications. The report concludes with a detailed synopsis of proposed scientific modifications to better assure the consistency between operational products, sounder measurements and expected values from radiative transfer models (and radiosondes). Dual sets of sounding products comprised of initial profiles regressed from microwave observations, and final (iterated) soundings that explicitly satisfy the sounder measurements are planned for climate and numerical weather prediction applications, respectively. This new approach is designed to better meet expanding user requirements and provide a consistent baseline for validating next generation NPOESS (and METOP) product systems.