Control surveys establish a common, consistent network of physical points that are the basis for controlling the horizontal and vertical positions of transportation improvement projects and facilities. Corridor control surveys ensure that adjacent projects have compatible control. Project control surveys provide consistent and accurate horizontal and vertical control for all subsequent project surveys - photogrammetric, mapping, planning, design, construction, and right of way.
We offer following Control surveys:
- Horizontal Corridor Control Surveys
- Horizontal Project Control Surveys
- Vertical Project Control Surveys
- Supplemental Control
Horizontal project control surveys shall be performed for all utility projects to define the geographic positions of project facilities.horizontal project control shall be established using GPS surveys complying with accuracy standard. When GPS survey methods cannot be used for all or part of a Horizontal Project Control Survey, a Total Station Survey System (TSSS) traverse network meeting accuracy standard is acceptable.
Vertical project control surveys shall be based on a single, common vertical datum to ensure that various phases of a project and contiguous projects are consistent.Vertical Project Control can be established using the following methods:
- Differential leveling
- Trigonometric leveling
- GPS can be used to bring NAVD88 to a project
Supplemental control surveys are undertaken to densify project control surveys. Supplemental control is used for establishing photogrammetric control, locating terrain data for engineering surveys, establishing setup points for construction staking, locating land net monuments, and setting right of way monuments. Supplemental control points may be used for both horizontal and vertical control.
Vertical Project Control can be established using the following methods:
- Differential leveling
- Trigonometric leveling
- GPS can be used to bring NAVD88 to a project
