Ground to grid correction is the process of converting ground measurements taken by surveyors or engineers to grid measurements on the projection surface of your map data. If necessary, you can set a ground to grid correction to ensure that new parcels are correctly rotated and scaled for the map projection of your parcel fabric.
Learn more about the ground to grid correction
To turn the ground to grid correction on or off in your project, click Ground To Grid 
in the Corrections group on the Edit ribbon.
Tip:
Ground To Grid is also available on the status bar at the bottom of an active map.When ground to grid correction is turned on, entered dimensions are assumed to be ground measurements. The correction applies an offset angle or basis of bearing to directions and multiplies distances by a distance factor. The Rotation field on the line feature class (parcel type line or connection line) is updated with the angular amount the line has been rotated to fit the parcel fabric. The Scale field on the line feature class (parcel type line or connection line) is updated with the scale factor value that has been applied to the line.
Learn more about setting the direction offset and distance factor
You can derive the ground to grid correction interactively by digitizing the ground and grid lines:
Example: Interactively derive a correction by entering the ground line and digitizing the grid line
If there is a basis of bearing line stated on your record document, and you can digitize the same line on the map, you can interactively derive the ground to grid correction. A record document states a basis of bearing when all the bearings on the record document are based on the bearing of a designated line. For example, the basis of bearing may be the line between two physical monuments. In the record document below, the dimensions of the road centerline between two monuments is a basis of bearing line. The dimensions of the line are S89°42'35"E and 278 feet.
In the parcel fabric, if the monuments exist as point features, a line can be digitized between the monuments to derive the ground to grid correction.
To interactively derive the ground to grid correction using the record above, click the Ground To Gird drop-down arrow and click Enter the ground line and digitize the grid line.
- Type the ground dimensions of the basis of bearing line under Enter the ground direction and distance.
In this example, the dimensions are S89°42'35"E and 278 feet.
- Click Next to digitize a grid line.
- Click the start and end points of the same line in the parcel fabric.
The start and end points should be monuments or points.
Click the start and end points of the grid line to digitize the line. When you click the end point of the grid line, the ground to grid correction is automatically computed and will be applied to all subsequent dimensions entered for the parcel fabric. Click the Ground To Gird
drop-down arrow to see the computed correction.
Example: Interactively derive a correction by digitizing both the ground and grid lines
If the basis of bearing is not obvious, you can digitize both a ground line and a grid line to interactively derive the ground to grid correction. The start and end points of the grid line should be present in the parcel fabric. These points can be parcel points or monuments. To obtain the start and end points of the corresponding ground line, the dimensions need to be accurately entered from the record document without the correction applied.
To enter the dimensions of the ground line, use dynamic constraints or the Traverse tool
In the example below, a line is traversed between two existing points in the parcel fabric without a ground to grid correction applied. The traversed line does not close or end on the expected end point because a ground to grid correction has not been applied.
The ground to grid correction can now be interactively derived by digitizing both the entered line and the expected grid line.
- Click the Ground To Gird drop-down arrow and click Digitize the ground line and the grid line.
- Click the start and end points of the ground line, which are the start and end points of the entered lines.
Click the start and end points of the ground line. - Click the start and end points of the grid line, which are the expected start and end points of the ground line you just entered into the parcel fabric.
Click the start and end points of the grid line. The ground to grid correction is automatically calculated and will be applied to to all subsequent dimensions entered for the parcel fabric.
Tip:
To apply the ground to grid correction to existing traverse lines, start a new traverse, click Modify and trace the traverse lines.
- Click the Ground To Gird drop-down arrow to see the computed correction.