U.S. Government Science Monitoring and GPS
GPS technology is inextricably tied to essential U.S. government scientific endeavors that help protect Americans in the air, on land, at sea and in space.
Top officials from the National Oceanic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA) and the United States Geological Survey (USGS) testified at a September 8, 2011 hearing of the Committee on Science, Space, and Technology. In their testimony, the officials detailed the myriad uses of GPS in U.S. government scientific efforts, efforts which often overlap agency boundaries, and are summarized below.
GPS is essential to carrying out a wide range of essential activities. These include major satellite, airborne, sea-based, and terrestrial systems used for weather forecasting, severe storm warnings, climate monitoring, fisheries management, coastal restoration, vessel navigation, nautical charting and geodesy, the scientific discipline that deals with the measurement and representation of the Earth.
More than 23,000 environmental sensor platforms across the planet depend on GPS for accurate geo-referencing and data time stamping, and the NEXRAD weather radars and sea surface radar altimeters require GPS-based time synchronization. NEXRAD is critical to issuing timely severe storm and flood warnings, and local weather forecasts. The instruments attached to weather balloons and dropped from aircraft into hurricanes are entirely dependent on GPS for accurate position and velocity measurements.
The nationwide network of Continuously Operating Reference Stations (CORS) collects and shares precise data about GPS satellite orbits. CORS provides a consistent positioning technology, accurate to an inch, which is used by millions of people throughout the country. This network is critical to anchoring nautical charts, building roads and railways, surveying airports, and responding to natural disasters and other emergencies.
The government relies on GPS technology and capabilities to monitor and improve the understanding of Earth science, including climate change and solid Earth hazards, as well as ocean topography measurements to determine currents and long-term changes in sea height.
GPS is critical to enabling accurate calibration of instruments aboard orbiting spacecraft as well as critical navigational tasks aboard Unmanned Aerial Vehicles (UAVs) and crewed aircraft.
GPS is also used in providing the data used to manage water resources, forecast floods and droughts, inform the design and operation of dams, levees, water and wastewater treatment plants, and irrigation systems, and the regulation and monitoring of water pollution and its impacts.
Monitoring the Earth's crust requires more than 1,000 permanent continuously operating GPS stations to track plate motions and monitor ground deformation due to earthquakes along faults. A system of 220 continuously reporting GPS stations is used to forecast and detect eruptions for volcanically active areas of the U.S.