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. If using a projected coordinate system, the properties of the underlying projectionProjection refers to a projected coordinate system based on a map projection such as transverse Mercator, Albers equal area, or Robinson, all of which project maps of the earth's spherical surface onto a 2D Cartesian coordinate plane.Learn more greatly influence the accuracy of measurements for a given area of the map. This type of measurement is in contrast to geodetic measurementA geodetic measurement is any method of measuring geographic distance or area that uses a curved (nonplanar) surface to model the Earth.Learn more, which uses a curved (nonplanar) surface to model the earth.