## What is a geocentric reference?

A coordinate system with its origin at the earth’s center, as distinct from one with an origin on the earth’s surface.

## Is WGS84 geocentric or geodetic?

world geodetic system
Well, WGS84 is a world geodetic system! So the data is not projected! It is a geodetic system with geocentric or geodetic coordinates based on the EGM96 geoid, the reference ellipsoid IAG GRS80, and the original meridian is the Greenwich meridian.

What is the difference between geocentric and geodetic?

Geodetic latitude is defined as the angle between the equatorial plane and the surface normal at a point on the ellipsoid, whereas geocentric latitude is defined as the angle between the equatorial plane and a radial line connecting the centre of the ellipsoid to a point on the surface (see figure).

### Is GPS geodetic or geocentric?

The Global Positioning System (GPS) uses the World Geodetic System 1984 (WGS 84) to determine the location of a point near the surface of Earth.

### Is WGS84 an ECEF?

To clarify, WGS84 is an Earth Centered Earth Fixed (ECEF) reference frame and utilizes both ECEF and latitude, longitude, and altitude (height) coordinates. Conversion is required from geocentric (x,y,z) to geodetic (lat, long, alt) coordinates.

What is a geodetic coordinate system?

A coordinate system in which position is specified by geodetic latitude, geodetic longitude and (in the three-dimensional case) ellipsoidal height, in accordance with EN ISO 19111.

## Is UTM a datum?

Geographical (latitude and longitude) and UTM (Universal Transverse Mercator) coordinate systems are positioned on the shape of the world by a “datum”. The model for the shape of the world that is used is called an “ellipsoid”.

## What is a UTM in GIS?

From wiki.gis.com. The Universal Transverse Mercator (UTM) coordinate system is a grid-based method of specifying locations on the surface of the Earth that is a practical application of a 2-dimensional Cartesian coordinate system.

What is geodetic coordinate system?

### Is ECEF geocentric?

The Earth-centered, Earth-fixed coordinate system (acronym ECEF), also known as the Geocentric coordinate system, is a cartesian spatial reference system that represents locations in the vicinity of the Earth (including its surface, interior, atmosphere, and surrounding outer space) as X, Y, and Z measurements from its …