Plane Survey Area Limit Explained

Plane surveying is a method used for relatively small areas where the Earth's curvature is considered negligible.

The assumption in plane surveying is that the surveyed area lies on a flat horizontal plane. This assumption holds true only up to a certain limit.

Determining the Survey Area Upper Limit

Beyond a specific area, the effect of the Earth's curvature becomes significant, leading to inaccuracies if plane surveying methods are used. The generally accepted upper limit for the application of plane surveying, beyond which geodetic surveying (considering curvature) is required, is approximately 250 square kilometers.

• This limit ensures that the error introduced by ignoring the Earth's curvature remains within acceptable tolerance for practical purposes.
• Areas larger than this threshold require techniques that account for the geoid or spheroid shape of the Earth.

Therefore, the upper limit of the survey area (in square kilometers) for the use of plane survey is 250.