Spectra Precision Survey Pro v4.5 Ranger User Manual User Manual

Page 211

GPS Overview

201

• ECEF XYZ

Geodetic coordinates are some times given in the Earth Centered
Earth Fixed (ECEF) Cartesian coordinate system. This coordinate

system has its origin at the Earth’s center of mass, the primary (Z)

axis is the earth’s spin axis; the secondary (X) axis is the intersection
of the equatorial plane and the mean meridian of Greenwich; the

tertiary (Y) axis is orthogonal in a right handed system. An ECEF
XYZ coordinate can be converted into the corresponding lat, lng, ht

using standard formulas.

For many surveying applications, the horizontal and vertical

coordinate systems are separate. Below are descriptions of common

horizontal and vertical coordinate systems used in surveying and
mapping.

Fig. 2: Earth Centered Earth

Fixed Geodetic Coordinates

Equator