Distance-Offset (COGO)

The Distance Offset COGO routine lets you create a new point or update the position of an existing point based on a distance an an offset left or right.

The distance can be some bearing or it can be the distance along an existing tangent/curve/spiral.

• Choose COGO | Distance Offset to display the Distance Offset dialog.  See Accessing COGO.
• Enter the From point, direction and distance. You can use equations to get the distance and direction from existing points or pick the data from the current drawing.
• Enter the Offset (enter a negative offset for left and a positive offset for right).
• Recall an existing point or enter a new point label in the Computed section and choose Save.
• Enter additional offsets as needed, choosing Save for each one.
• When you are finished, choose Close.

Modifying an Existing Point

It's easy to modify the position of an existing point. Just select that point in the Points Manager or Traverse View or position the cursor over it's point label or point symbol in the current drawing then right click and choose COGO | Distance Offset. The selected points is entered in the Computed Point field. This lets you quickly tweek the position of an existing point.

Creating a Point at a Station and Offset

• From the Traverse View for the traverse that defines the alignment you want, choose COGO | Station Offsets.
• TPC uses the stationing of the alignment traverse to determine the location of the station, then computes an offset from that station point.
• Bot the computed station point and the offset point are inserted into the traverse at the appropriate location.

Distance Along a Curve or Spiral

If the From and To points you enter reference an existing line, the Distance you specify in this dialog is along that line. So if you enter the end points of a curve, TPC will compute a point on that curve, the specified Distance from the From point, then compute the perpendicular offset.

Accessing this Dialog

If you access this routine from the Traverse View or Point Manager, the highlighted point becomes the Computed point, saving you keystrokes.

If you access this routine from the Drawing View, TPC evaluates the drawing object you selected. If that object references a survey point, that survey point becomes the Computed point.

TPC does not automatically pre-set the line used in this dialog when you access it from a view because it uses the selected data to pre-set the Computed point.