What is WGS?
World Geodetic System is also known in its shortened form as WGS. It is basically the standard used for geodesy, cartography and navigation. This standard is composed of important Earth coordinate frame. It also includes the standard used for spheroidal reference surface. This is the reference ellipsoid or datum needed to achieve the unprocessed statistics of the altitude. The gravitational equipotential plane is also known as the geoid and it is likewise included which is the defining element of the supposed sea altitude.
WGS basically has different and updated versions. The latest is the WGS 84 which was created from 1984 while the most recently revised version is in 2004. This most up to date edition is valid until about 2010. However, there are also much earlier editions and schemes such as the WGS 60, WGS 66 and WGS 72. The Global Positioning System however utilizes the WWGS 84 revision as the reference coordinate system.
To know more about WGS, it helps to understand that its coordinate origin, specifically the WGS 84, is preferably at the center of the Earth’s mass. However, there is a recorded error in this system which is known to be just less than a couple of centimeters. With the latest WGS 84 revision, the datum surface has an oblate spheroid definition or also known as the ellipsoid. In the contemporary usage of the system, it applies the 1996 Earth Gravitational Model also known as the EGM96 GEOID. This was revised in 2004 and through the use of spherical harmonics series, describes the approximated level of the sea.
The EGM96 is the most recent revision of the WGS. This model uses the same ellipsoid reference as that with WGS 84. However, it has much higher fidelity geoid compared to the previous versions. The model has roughly 100 kilometer resolution versus the 200 kilometer resolution used in the WGS 84 version.