Measurement accuracy for small distances – geodesic vs. planar UTM WGS84

Should I use planar or geodesic?

Geodesic distance always produces a more accurate result and is the recommended method, unless speed is more important than accuracy. The difference between planar and geodesic calculations of distance and direction varies with map projection and size of the study area.

What is the difference between UTM and WGS84?

The difference is that WGS 84 is a geographic coordinate system, and UTM is a projected coordinate system. Geographic coordinate systems are based on a spheroid and utilize angular units (degrees).
 

What is planar measurement?

Planar measurements are measurements made on a flat surface. When using geographic coordinates, planar measurements must cut through the curved surface of the earth, causing the measurement to be shorter than the true distance. This error becomes greater as the length of the line increases.

Is WGS84 a projection or datum?

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). It is a global datum, which means that coordinates change over time for objects which are fixed in the ground.

Is a geodesic the shortest path?

A shortest path, or geodesic path, between two nodes in a graph is a path with the minimum number of edges. If the graph is weighted, it is a path with the minimum sum of edge weights. The length of a geodesic path is called geodesic distance or shortest distance.

What projected coordinate system should I use?

Your choice of a projected coordinate system depends on many factors, including the part of the world you are mapping, the scale of your map, and the purpose of your map. You want to choose a projected coordinate system in which the places and properties that are most important to your map are the least distorted.

Is UTM more accurate?

The military uses their own implementation of the UTM system, called the Military Grid Reference System (MGRS). One system is no more or less accurate than the other. They are just two different ways of positioning a point.

How accurate is WGS84?

2-5 metres

The accuracy of WGS84 (G2139) as realised using the broadcast ephemeris and ranging data is now typically 2-5 metres.

How accurate is UTM?

They are accurate to around a millimeter within 3000 km of the central meridian.

What are geodesics used for?

Applications. Geodesics serve as the basis to calculate: geodesic airframes; see geodesic airframe or geodetic airframe. geodesic structures – for example geodesic domes.

What does the geodesic equation tell us?

The geodesic equation is useful in establishing one of the necessary theoretical foundations of relativity, which is the uniqueness of geodesics for a given set of initial conditions.
 

What are geodesic problems?

Abstract The direct geodesic problem on an oblate spheroid is described as an initial value problem and is solved numerically in geodetic and Cartesian coordinates. The geodesic equations are formulated by means of the theory of differential geometry.