Quick Answer: What Does WGS 84 Mean?

What is pseudo Mercator?

The Web Mercator / Pseudo Mercator projection is a cylindrical map projection.

This is a variant of the regular Mercator projection, except that the computation is done on a sphere, using the semi-major axis of the ellipsoid..

Why do we use WGS 84?

WGS84: Unifying a Global Ellipsoid Model with GPS The radio waves transmitted by GPS satellites and trilateration enable extremely precise Earth measurements across continents and oceans. Geodesists could create global ellipsoid models because of the enhancement of computing capabilities and GPS technology.

What is the difference between UTM and wgs84?

UTM is common for larger GIS projects. WGS84 allows you to have a datum in the full meaning of the term, and this is projected using the map projection. UTM is a map projection system: Universal Transverse Mercator. … In GIS, specifying WGS84 as the datum means you can use GPS data directly.

How accurate is wgs84?

2-5 metresThe accuracy of WGS84 (G1762) as realised using the broadcast ephemeris and ranging data is now typically 2-5 metres.

How do you calculate UTM?

UTM coordinate of a point is stated by writing the zone, easting and then northing values. When finding a position on a map, it is helpful to “read right up”, that is to read west to east to find the easting and then south to north to find the northing of the location.

What is chart datum wgs84?

WGS84 is a mathematical model of the Earth intended as a compromise that reasonably represents the world for practical navigation purposes. Your satellite positioning system should be set to give positions referenced to WGS84 when using any official Australian ENC or PNC.

What is UTM Easting?

A Universal Transverse Mercator coordinate comprises a zone number, a hemisphere (N/S), an easting and a northing. Eastings are referenced from the central meridian of each zone, & northings from the equator, both in metres. Eastings are measured from 500,000 metres west of the central meridian. …

Does Google Earth use wgs84?

Our automated system analyzes the replies to choose the one that’s most likely to answer the question. Google Earth,or any GIS model, has to use a reference datum. GE uses WGS84 because that’s the same datum GPS uses.

What datum is used by Google Earth?

geographic coordinate systemGoogle Maps and Microsoft Virtual Earth use a Mercator projection based on the World Geodetic System (WGS) 1984 geographic coordinate system (datum). This Mercator projection supports spheres only, unlike the ESRI Mercator implementation, which supports spheres and ellipsoids.

What is the difference between Itrf and wgs84?

The main difference between ITRF and WGS84 reference frameworks is the choice of fixed stations used in their adjustments. Not surprisingly, the difference between WGS84 and ITRF 2000 is now very small, generally less than 10 millimetres.

What datum does Iphone GPS use?

WGS-84The default datum used by iOS location services, and Pro Compass, is WGS-84 (WGS stands for “world geodetic system” and 84 refers to “1984”, the year of this standard). WGS-84 is an ellipsoidal model that approximates the surface of the Earth.

Who uses UTM?

They are just two different ways of positioning a point. Many experienced users prefer UTM over latitude/longitude when using 7.5′ topographic quadrangle maps. Ocean-going sailors and other marine users almost always use latitude/longitude because navigation charts are optimized for this method.

What are the 4 types of map projections?

Types of Map ProjectionsGnomonic projection. The Gnomonic projection has its origin of light at the center of the globe. Less than half of the sphere can be projected onto a finite map. … Stereographic projection. The Stereographic projection has its origin of light on the globe surface opposite to the tangent point. … Orthographic projection.

Is UTM a geographic coordinate system?

UTM stands for “Universal Transverse Mercator”. It is a geographic coordinate system which is used to identify locations on earth in meters, as measured in the Northern Hemisphere going North and East from the intersection of the equator and a central meridian assigned to each of 60 longitudinal zones around the earth.

How do I get UTM on Google Earth?

Open Google Earth.At the top, click Tools. Options.Click 3D View. Then, under “Show Lat/Long,” choose a display format.Click OK. Coordinates will be displayed in the lower right corner.

Is WGS 84 a projection system?

For example, the “WGS84 projection” is a geographic one. A UTM projection is a projected one. Either of these will use only one datum. However, the data on the map could have come from multiple sources, all with unique projections and therefore datums.

Why are there hundreds of datums?

A geodetic datum is a tool used to define the shape and size of the earth, as well as the reference point for the various coordinate systems used in mapping the earth. Throughout time, hundreds of different datums have been used – each one changing with the earth views of the times.

Is nad83 a coordinate system?

The North American datum of 1983 (NAD 83) is the United States horizontal or geometric datum. … Projected coordinate systems are based on geographic coordinates, which are in turn referenced to a datum. For example, State Plane coordinate systems can be referenced to either NAD83 and NAD27 geodetic datums.

What is the difference between datum and coordinate system?

A datum is simply a foundation and reference for spatial measurements. A system of coordinates is then used to describe those measurements relative to the datum, and a projection is the visual representation of those measurements on a different surface.

What elevation datum does Google Earth use?

EGM963 Answers. The heights on google earth refer to EGM96 and are, therefore, Geoidal heights. The lat/long are referred to the WGS 84 ellipsoid.