A common task for surveyors, civil engineers and GIS professionals is recreating a property boundary from a plat (a map, drawn to scale, showing the divisions of a piece of land). Typically, a plat will contain the bearings (direction expressed in degrees) and perimeter distances (lengths of the edges) of the property it describes. By changing just a few settings, MicroStation allows you to quickly and easily recreate a property boundary by bearing and distance.
First off, you’ll want to use a seed file with the correct working units and coordinates. Assuming the plat is done in bearings, decimal feet and on a State Plane Coordinate System (system for specifying positions using plane rectangular coordinates), we’ll use the “2dEnglishMapping.dgn” seed file that comes with MicroStation. Using this seed file, create a new drawing and call it “plat.dgn”.
Once you’re in the new drawing, you’ll want to change a few settings. Go to the “Settings” menu and select “Design File”. A dialog box will appear, select “Coordinate Readout” and change the “Coordinates and Angles” settings to those shown in the graphic below and click <OK> to close the dialog box. You are setting MicroStation to work in decimal feet to the nearest hundredth and to work in bearings to the nearest second.
Using whatever attributes are active, you can now begin drawing. First, go to the “Help” menu and select “Key-in Browser”. This will open a dialog box with a command line for you to enter coordinates to draw the boundary of your plat. Now, select the “Line” tool. You will be prompted for a starting point, just enter “XY=1000,1000″ in the command line and hit <Enter>. For the remaining legs of your plat, you will enter polar coordinates by bearing and distance using the format “DI=DISTANCE, BEARING”. In the command line, enter the following bearings and distances:
If necessary, click on “Fit View” to look at your drawing. The plat boundary should now be displayed. I always measure the distance from the starting point and ending point as a closure check. Just use the “Measure Distance” tool, select “Between Points” and measure, snapping to the endpoints of the beginning and ending line segments. You can also use the “Measure Element” tool to check the bearing and distance of each boundary line.
I hope this article has been of help to you. I use this process all the time in my own office. Good luck!
Brett Thompson is a graduate of Eastern Illinois University and serves as GPS/GIS Coordinator for the City of Monticello, Illinois. He has been a long-time user of MicroStation and has taught MicroStation at the community college level.