About Performing a Mapcheck Analysis

Use the Mapcheck Analysis command to perform a mapcheck that is based on the precision of the annotation of the label object.

The Mapcheck Analysis command computes mapcheck calculations directly from the selected labels. To perform a mapcheck you must specify a point of beginning (POB) for each parcel. For each segment within the parcel, you select a label containing a direction, direction and distance, distance label, or curve label until the requirements to compute the next vertex of the current segment are met.

As you perform a mapcheck, temporary graphics are displayed in the drawing to indicate the sides that have been entered for each parcel. The current side is displayed in bold indicating origin and direction for that side. The temporary graphics also provide a visual confirmation of possible errors, or indicate that the direction of a line or curve needs to be flipped or reversed.

Note: The mapcheck report data is stored in the drawing database so you can continue a mapcheck from a previous Autodesk Civil 3D session. The Mapcheck Analysis window must be open to enable the display of the temporary graphics.

From the POB, the annotation for each side in the parcel is used to calculate the coordinates of the endpoint of the side. As you enter data for each parcel, the Output View in the Mapcheck Analysis window updates to indicate error of closure and area based on the previously entered sides. Entering the information for the last side closes to the POB. The Mapcheck Analysis output view contains the following information:

• POB coordinates
• A sequential list of each course, direction and distance, or curve data, and end point coordinates
• An error of closure summary: Error of closure: 1 part in <X parts>
• Error of closure direction: <bearing or azimuth>
• Error of closure distance: <distance>
• Perimeter distance: <total distance around the parcel>
• Area: <area units (acres/hectares, and square feet/meters>

For each parcel or survey figure, the area annotation is compared to the mapcheck area. If the error of closure is acceptable, for example a closure that exceeds one part in 10,000 parts and the area annotation matches, the annotations are considered to be mathematically correct.

You can copy the report content to the Windows Clipboard, or print it to a TAB delimited ASCII text file.

Tutorial Exercise: Performing a Map Check Analysis with Parcel Labels