National Geodetic Survey

National Geodetic Survey. The National Geodetic Survey is a United States federal agency that defines and manages a national coordinate system, providing the foundation for transportation and communication, mapping and charting, and a multitude of scientific and engineering applications. It is an office within the National Oceanic and Atmospheric Administration (NOAA), part of the United States Department of Commerce. The agency's data and models are critical for accurate positioning, from supporting the Global Positioning System to measuring sea level change and monitoring crustal motion.

History

The agency's origins trace back to 1807 when President Thomas Jefferson signed a bill authorizing the United States Coast Survey, the nation's first scientific agency, tasked with charting the coastal waters of the young republic. Under the leadership of early superintendents like Ferdinand Rudolph Hassler and Alexander Dallas Bache, the survey expanded its work into precise geodetic measurements. Following the American Civil War, the agency was renamed the United States Coast and Geodetic Survey and began extensive triangulation work to establish a national datum. A pivotal moment came with the adoption of the North American Datum of 1927, which standardized coordinates across the continent. In 1970, the organization was transferred to the newly formed National Oceanic and Atmospheric Administration and received its current name, focusing on modern satellite-based geodesy and the development of subsequent datums like the North American Datum of 1983.

Mission and functions

The core mission is to define, maintain, and provide access to the National Spatial Reference System (NSRS), the consistent coordinate framework that defines latitude, longitude, height, scale, gravity, and orientation throughout the United States. Key functions include operating a nationwide network of permanent Global Navigation Satellite System stations, known as the Continuously Operating Reference Station (CORS) network, which supports real-time positioning. The agency also conducts airborne and terrestrial surveys to measure Earth's gravity field and conducts precise leveling to determine elevations. Furthermore, it provides authoritative data on shoreline boundaries and assists in the definition of the Exclusive Economic Zone for the United States.

Key programs and products

A flagship program is the modernization of the National Spatial Reference System, which will replace traditional vertical datums with a new North American-Pacific Geopotential Datum of 2022. The Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project collects airborne gravity data to support this effort. Primary products include a vast database of survey markers, or geodetic control points, accessible via the Integrated Database (IDB). The agency also produces software tools like the NGS Toolkit and provides online positioning services such as the Online Positioning User Service (OPUS). Its Vertical Datum Transformation tool (VDATUM) is essential for converting data between tidal, orthometric, and ellipsoidal height systems.

Organizational structure

The agency is headed by a director and is organized into several divisions focusing on different technical areas. These typically include divisions for Spatial Reference System Requirements and Standards, Observation and Analysis, and Remote Sensing. It maintains regional advisors and geodetic specialists who work directly with states, tribal nations, and other federal partners like the United States Geological Survey and the Federal Emergency Management Agency. The agency's workforce comprises geodesists, surveyors, physicists, and computer scientists who operate from its headquarters in Silver Spring, Maryland, and field offices across the country.

Impact and applications

The data and standards are foundational for the National Spatial Data Infrastructure and critical for the safe and efficient construction of infrastructure, including projects overseen by the Federal Highway Administration and the Federal Aviation Administration. They support precision agriculture, land surveying, and the mapping efforts of the United States Census Bureau. In science, the data are vital for monitoring plate tectonics and subsidence, studying sea level rise with partners like the NASA Jet Propulsion Laboratory, and understanding changes in the gravity field. During events like Hurricane Katrina or the 2011 Tōhoku earthquake and tsunami, its data were crucial for emergency response and recovery efforts.

Category:National Oceanic and Atmospheric Administration Category:Geodesy organizations Category:1807 establishments in the United States