As the name states, this points controlling the project accuracy. one or two known station can be obtained from the authorities and it known as benchmark. Usually the project will be far from the bench marks thus leads to shift the benchmark value to the project area.
The job should do by maximum accuracy and the value should close back to the same benchmark from where we start. It can be perform by GPS and total stations. for a long distance GPS is more accurate. two or more control points can be establish for the convenience of construction. Report with value of points will be provided.