Search results
A geographic coordinate system (GCS) uses a three-dimensional spherical surface to define locations on the earth. A GCS is often incorrectly called a datum, but a datum is only one part of a GCS. A GCS includes an angular unit of measure, a prime meridian, and a datum (based on a spheroid ).
Mar 25, 2024 · Latitude and longitude, coordinate system by means of which the position or location of any place on Earth’s surface can be determined and described. Latitude is a measurement of location north or south of the Equator. Longitude is a similar measurement east or west of the Greenwich meridian.
Geographic coordinate systems form the first level of defining where we are on the earth. All spatial data must first address the curved surface of the earth, thus all coordinate systems will have a geographic coordinate system “core” that defines the spheroid, geoid, units of measure, and prime meridian on which all further measurements ...
May 21, 2023 · The coordinate system used to define locations on the three-dimensional earth is the geographic coordinate system (GCS), based on a sphere or spheroid. A spheroid (a.k.a. ellipsoid) is simply a slightly wider sphere than it is tall and approximates the actual shape of the earth more closely.
Figure 2.11.1 The geographic coordinate system. Longitude specifies positions east and west as the angle between the prime meridian and a second meridian that intersects the point of interest. Longitude ranges from +180 (or 180° E) to -180° (or 180° W). 180° East and West longitude together form the International Date Line.
Jan 21, 2023 · LibreTexts. Learning Objectives. The objective of this section is to describe and discuss the concepts of map scale, coordinate systems, and map projections and explain why they are central to maps, mapping, and geographic information systems (GISs). All map users and map viewers have certain expectations about what is contained on a map.
The geographic coordinate system is designed specifically to define positions on the Earth's roughly-spherical surface. Instead of the two linear measurement scales, x and y, the geographic coordinate systems juxtaposes two curved measurement scales.
