Which term refers to surveys covering extensive areas with consideration of the curvature and geoid-spheroidal shape of the earth at sea level for the purpose of establishing a basic network of reference points?

• A. Geodetic Control Surveys
• B. Control Surveys
• C. Project Control Surveys
• D. Cadastral Surveys

Answer: (A)

Geodetic control surveys are designed for large-area work where the curvature of the Earth and the geoid-spheroidal shape relative to mean sea level must be incorporated. This approach establishes a nationwide or regional network of reference points tied to a single geodetic datum (using an ellipsoid and geoid model) so coordinates are consistent over long distances and across varied terrain. That foundational network then supports accurate mapping, engineering, and navigation.

Other types focus on different scopes: control surveys can be more general or local without a nationwide geodetic framework; project control surveys pertain to the control points needed for a specific project; and cadastral surveys concentrate on precise boundary determinations for land parcels, typically at a local scale rather than a broad reference network.