JPSS CGS SNPP Performance

The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by the National Oceanic and Atmospheric Administration. The Joint Polar Satellite System satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground processing system for the Joint Polar Satellite System is known as the Common Ground System (JPSS CGS), and provides command, control, and communications (C3) and data processing and product delivery. As a multi-mission system, CGS provides combinations of C3, data processing, and product delivery for numerous NASA, NOAA, Department of Defense (DoD), and international missions, such as NASA's Earth Observation System (EOS), NOAA's current POES, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission – Water (GCOM-W1), and DoD's Defense Meteorological Satellite Program (DMSP).

The first satellite in the JPSS constellation, known as the Suomi National Polar-orbiting Partnership (SUOMI NPP) satellite, was launched on 28 October 2011, and is currently undergoing product calibration and validation activities. As products reach a beta level of maturity, they are made available to the community through NOAA's Comprehensive Large Array-data Stewardship System (CLASS). CGS's data processing capability will process the satellite data from the Joint Polar Satellite System satellites to provide environmental data products (including Sensor Data Records (SDRs) and Environmental Data Records (EDRs)) to the National Oceanic and Atmospheric Administration and Department of Defense processing centers operated by the United States government. CGS is currently processing and delivering SDRs and EDRs for Suomi NPP and will continue through the lifetime of the Joint Polar Satellite System programs.

Following the launch and sensor activation phase of the SUOMI NPP mission, full volume data traffic is now flowing from the satellite through CGS's C3, data processing, and data delivery systems. Ground system performance is critical for this operational system. As part of early system checkout, Raytheon measured all aspects of data acquisition, routing, processing, and delivery to ensure operational performance requirements are met, and will continue to be met throughout the mission. Raytheon developed a tool to measure, categorize, and automatically adjudicate packet behavior across the system, and metrics collected by this tool form the basis of the information to be presented. This presentation will provide details of ground system processing performance, such as data rates through each of the CGS nodes, data accounting statistics, and retransmission rates and success, along with data processing throughput, data availability, and latency. In particular, two key metrics relating to the most important operational measures, availability (the ratio of actual granules delivered to the theoretical maximum number of granules that could be delivered over a particular period) and latency (the time from the detection of a photon by an instrument to the time a product is made available to the data consumer's interface), are provided for Raw Data Records (RDRs), SDRs, and EDRs. Specific availability metrics include Adjusted Expected Granules (the count of the theoretical maximum number of granules minus adjudicated exceptions (granules missing due to factors external to the CGS)), Data Made Available (DMA) (the number of granules provided to CLASS) and Availability Results. Latency metrics are similar, including Data Made Available Minus Exceptions, Data Made Latency, and Latency Results. Overall result, measured during a ninety day period from October 2012 through January 2013, are excellent, with all values surpassing system requirements.