What is the primary difference between a "Geodetic" bearing and a "Grid" bearing?

The distinction between a "Geodetic" bearing and a "Grid" bearing lies primarily in their underlying references. A Geodetic bearing accounts for the curvature of the Earth and is based on actual geographic coordinates derived from the Earth's surface. This type of bearing is essential for high-precision measurements, especially over larger distances, as it contemplates the Earth’s spherical nature.

In contrast, a Grid bearing is derived from a flat projection of the Earth's surface, generally represented in a two-dimensional coordinate system. This method simplifies the calculations required for surveying and mapping at smaller scales, where the curvature of the Earth has less impact on accuracy.

Understanding this difference is crucial for land surveying practices, as choosing the appropriate bearing type can significantly affect the accuracy and reliability of survey results. Geodetic bearings will be more appropriate in scenarios requiring high precision, while Grid bearings may be used for local projects where the curvature is negligible.