英文摘要 |
A leveling benchmark is a commonly used surveying monument that serves as a reference point for leveling surveys. The primary function of a benchmark is to provide support for accurate leveling measurements. Typically, the face of a benchmark is positioned horizontally, featuring a convex shape on top to define a unique level in the vertical dimension. This configuration allows for the placement of a leveling rod during surveying activities. While horizontal placement is the norm for benchmarks, it is also possible to position them vertically. In this case, the face of the benchmark is aligned parallel to the plumb line, and it is referred to as a ''vertically set benchmark'' (vertical benchmark). This writing documents a vertical set benchmark encountered by the author during a visit to the San Francisco tide station in June 2023. The methods described can be applied to leveling surveys utilizing a vertical set benchmark. |