For what type of surveys is the size and shape of the Earth considered?

The size and shape of the Earth are important considerations in geodetic surveys because they account for the Earth's curvature and its physical characteristics, which can affect measurements over large distances. Geodetic surveys use sophisticated mathematical and physical models to understand the Earth as an ellipsoid, allowing surveyors to determine precise locations, elevations, and distances across vast areas. This level of detail is essential for mapping and maintaining accuracy in activities such as satellite positioning, boundary determination, and large-scale construction projects.

In contrast, other survey types, such as precision surveys, plane surveys, and mapping surveys, typically operate under the assumption that the Earth is flat, which is valid for shorter distances where curvature does not significantly impact the accuracy of the measurements. Thus, for larger scale and more precise work that involves the Earth’s shape, geodetic survey techniques are employed.