# What is WGS 84 reference ellipsoid?

## What is WGS 84 reference ellipsoid?

The ellipsoid WGS-84, widely used for mapping and satellite navigation has f close to 1/300 (more precisely, 1/298.257223563, by definition), corresponding to a difference of the major and minor semi-axes of approximately 21 km (13 miles) (more precisely, 21.3846858 km).

## What are the basic parameters of WGS 84?

Defining Parameters: WGS 84 identifies four defining parameters. These are the semi-major axis of the WGS 84 ellipsoid, the flattening factor of the Earth, the nominal mean angular velocity of the Earth, and the geocentric gravitational constant as specified below.

**What ellipsoid does WGS84 use?**

The North American 1983 datum (NAD83) uses the Geodetic Reference System (GRS80) ellipsoid while the World Geodetic System of 1984 (WGS84) uses the WGS 84 ellipsoid.

**Is WGS84 an ellipsoid?**

WGS84 is made up of a reference ellipsoid, a standard coordinate system, altitude data, and a geoid. The error of WGS84 is believed to be less than 2 centimeters to the center mass.

### What is meant by WGS 84?

The World Geodetic System 1984 (WGS84) is a datum featuring coordinates that change with time. WGS84 is defined and maintained by the United States National Geospatial-Intelligence Agency (NGA). It is consistent, to about 1cm, with the International Terrestrial Reference Frame (ITRF).

### What are the dimension of WGS 84?

The WGS 84 meridian of zero longitude is the IERS Reference Meridian, 5.3 arc seconds or 102 metres (335 ft) east of the Greenwich meridian at the latitude of the Royal Observatory. The WGS 84 datum surface is an oblate spheroid with equatorial radius a = 6378137 m at the equator and flattening f = 1/298.257223563.

**What units does WGS 1984 use?**

The WGS84 Coordinate Systems adds Greenwich as the starting point (prime meridian) for the longitude (0°) and sets the units in degrees (°). This coordinate systems also has a unique reference code, the so-called EPSG code which is 4326.

**Where is WGS 84 used?**

GPS

The most known use case is GPS, which uses WGS84 as its coordinate system. Your drone also contains a GPS which is used to tag the pictures acquired with your drone with coordinates and elevations that are determined in the WGS84 coordinate system.