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Geodesy icon - a globe

Geodesy

The science of accurately measuring and understanding the Earth's geometric shape, orientation in space, and gravity field.

partial gravity map for Hawaii

Reaching New Heights: A New Vertical Datum

Learn about a project to survey the nation's gravity field that will soon allow us to calculate heights to within about an inch for most locations in the United States.
3D shipwreck of submarine in North Carolina

A Tale of Three Datums

NOAA is currently working on three major updates to vertical datums. They’re used for everything from nautical charts and flood maps to infrastructure planning.
a map of coastal areas

Geographic Information Systems (GIS)

GIS describes a wide variety of computer-aided tools and services that capture, store, check, and display information related to positions on Earth’s surface.
A LIDAR (Light Detection and Ranging) image created with data collected by NOAA's National Geodetic Survey

Remote Sensing

Remote sensing is the science of obtaining information about objects or areas from a distance, typically from aircraft or spacecraft.
a geodesist in the field

Geodesy Defined

Geodesy is the science of accurately measuring and understanding three fundamental properties of the Earth.
A Global Positioning System is set up on a benchmark in Shell Beach, Louisiana.

Global Positioning

Global positioning is fundamental to navigation, communication systems, mapping and charting, and much more.
An airplane flying over a coastal area

Aerial Photography and Shoreline Mapping

Since the early 1900s, the National Geodetic Survey has been taking photographs from airplanes to capture the Earth below.