Control Points

Control points are used to link the paper drawing to real world GPS coordinates when exporting the surface model points, exporting the takeoff as a DWG file, or importing GPS points from a CSV file.

Preferably, two control points are defined. The points then define the scaling and rotation information necessary for the export/import.

At a minimum, one control point is required. If only one point is available, the North/South direction must be defined. It provides the rotation information for the export/import. The Scale defined for the takeoff will be used to provide the scaling information.

Control points are defined by pressing the Ctrl Pnt 1 or Ctrl Pnt 2 buttons on the Import/Export toolbar on the Drawings Tab. After clicking on the button, click on the point on the drawing. Then enter the Northing and Easting on the Control Point Toolbar.

After the coordinates are entered, press the OK button. The point can be reentered by pressing the Delete Last Point button. The process can be aborted by pressing the Cancel button.

Note: If using metric scaling, be sure to set the scale before setting the control points. When using metric scales, the control points are stored with two digits following the decimal point. When using English scales, only one digit following the decimal point is used.

Note: In previous versions of SiteWorx/OS, Control points were called Reference points.