How to draw a circle using COGO in PC-GPS, PC-MAPPER and CMT-Forester?

“I would love to see CMT forester have the ability to draw a circle. More and more, my farmers are asking me to cut a circle out of their forest, so they can install a circular, pivoting irrigation system, which is very common for this area. They resort to hiring a
surveyor, who is very expensive, and who can not always start as quickly as the farmer would like.”

You could make a circle using the COGO functions, which are provided in CMT-Forester, PC-GPS and PC-MAPPER. Following are two examples.

A. Known Radius Point

1. Create a Point Feature in the Job map that will serve as the radius point (i.e. the center of the circle).

2. Select COGO – Horizontal Curve
Enter the desired radius, such as 50 ft.
Select the Point Feature as the RP.
Enter 359 into the Cent Angle field.
Leave the PI -> PC direction as it is.
Press the Solve button then click on Store to create the curve.

3. Zoom into the tiny gap in the drawing.
Use Utilities – Join Lines/Points to join the three points together.
Mark the “Cursor Selected” option then click on each of these three points.
For the Result Topic, select Area as the Type if you wish to create an Area Feature.
Click on Join. The circle is now complete.

B. Known Point of Intersection

1. Choose or create a Point Feature in the Job map. This could be a property corner.

2. Select COGO – Curve by Radius.
Select the Point Feature as the PI.
Enter the desired radius, such as 50 ft.
For PI -> PC, confirm the N0E.
For PI -> PT, enter N90W.
Press the Tab key on your PC keyboard to pin down the angle.
Press the Solve button then click on Store to create the curve.

3. Tap on the Reset button then do the other part of the circle as follows.
Select the same Point Feature as the PI.
Enter the same radius, such as 50 ft.
Change the direction for PI -> PC to N90W.
For PI -> PT, enter N0W.
Press the Solve button then click on Store to create the curve.

4. Now you can use Utilities – Join to join the two curves into one.
For the Result Topic, select Area as the Type if you wish to create an Area Feature.
You may opt to delete the original partial curves.
Click on Join. The circle is now complete.

You could change the size of the symbol for the COGO points to be really small.
Or, you could make a user-defined symbol that is a blank.
Or, you could simply delete them.

You can move the circle anywhere you want after clicking on it while holding down the Ctrl button on your PC keyboard. Click anywhere else on the screen to get out of this “floating Feature” mode.

 

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