The National Weather Service operational requirements for the evolution of future NOAA operational geostationary satellites

In January, 1999 the National Weather Service (NWS) documented its operational requirements for a next generation of Geostationary Operational Environmental Satellite (GOES) system for the year 2010 time frame. The system of operational geostationary satellites is one of the primary observing systems needed by the NWS to fulfill its mission of providing weather, hydrologic, and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas. Since operational needs evolve with time and are influenced by budgetary and programmatic considerations, the requirements for the new generation of geostationary satellites should be viewed as an initial baseline that will enable the initiation of new sensor designs and cost studies. The NWS will continue to work with the National Environmental Satellite and Data Information Service (NESDIS) to refine the system definition. Requirements are listed for: 1) an Imager; 2) an IR Sounder; 3) Space Environment Monitoring; 4) Data Collection Platforms/System (DCP/DCS); 5) Emergency Manager's Weather Information Network (EMWIN); 6) Backup capability; 7) Microwave Sounder/Imager; 8) Low Light Imager; 9) Growth capability; and 10) Continuity of data. For critical elements, two types of performance levels are listed: threshold and goals. The threshold performance level is the minimum acceptable requirement; and a goal is a requirement which if met, would greatly enhance utility of the data in NWS operations. While it is unlikely that all the goals will be met in the 2010 time frame, the top priorities for improved capabilities in the next generation GOES include: 1) continuous operation during eclipse and keep out zone periods; 2) meet simultaneous global, climatic, synoptic, and mesoscale data needs; 3) improve temporal and spatial resolution of the imager data; and 4) improve the spatial coverage of the Sounder. This paper will cover the highlights of specific observing requirements and expected operational benefits.