What is the function of vertical control points in surveying?

Vertical control points are fundamental to surveying as they serve primarily to determine ground elevation at specific locations. These points are established through precise leveling techniques and provide a reference framework for measuring vertical distances. By identifying the elevation of various points on the Earth's surface, surveyors can accurately gauge height differences, which is essential for construction, grading, and land use planning.

The significance of vertical control points extends to various applications, such as ensuring that structures are built to the correct height, mitigating drainage issues, and aiding in the design of roadways and other infrastructure. Given their role in ascertaining elevations, vertical control points are vital for providing consistent and reliable data that enhances the overall accuracy of a surveying project.

The other options, while related to surveying, do not accurately describe the primary function of vertical control points. Establishing benchmarks for horizontal measurements involves horizontal controls rather than vertical ones. Data for land ownership typically includes deeds or legal descriptions, which are not directly linked to the role of vertical control points. Lastly, outlining property boundaries is more about horizontal measurements and legal definitions, rather than vertical elevation determination.