Coordinate geometry (COGO) is used to map the location of features and their boundaries measured on the ground and recorded on survey plans, deed descriptions, and other types of physical or electronic land record documents.
COGO measurements typically describe features relative to each other. The following example survey plan shows COGO measurements for a road centerline and parcel boundaries adjoining the road.
Survey plans can include references to points with known coordinates that spatially locate or georeference COGO features within a coordinate system. These points are known as control points, monuments, or cadastral reference points.
In ArcGIS Pro, COGO descriptions comprise a set of measurements that define a line feature.
- Straight lines are described with a direction and a distance.
- Curved lines include a radius, angle, arc length, and chord direction.
- Spirals are described with two radii. The second radius can be set to infinity.
Spirals describe transitions to and from circular curves or straight tangents, for example, to record the designed alignment for a roadway or railroad.
Enabling COGO for a line feature class adds COGO attribute fields and COGO-enabled labeling to the feature class. COGO fields are used to store survey measurements typed into COGO-aware editing tools.
In addition to COGO-enabled line features, you can use simple point, line, and polygon features to represent COGO features described below.
- Points can represent the endpoints of measured lines and curves. Points can also represent surveyed points and have known x,y,z coordinates. You can use a simple point feature class with x, y, z attributes to represent these points, or use a parcel fabric to manage parcel points.
- Lines can represent measured distances and directions. Measured lines can also represent circular arcs and spiral curves. You can use a simple line feature class or manage parcel lines in a parcel fabric. Examples of common tools that create COGO lines include the Two-Point line tool, the Circular Arc tool, and the Traverse tool.
- Polygons can represent parcel areas enclosed by COGO lines. You can use a simple polygon feature class or manage parcel polygons in a parcel fabric. Polygon features can be created with the Construct Polygon tool by starting from selected COGO lines. Polygons can also be created using the Traverse tool.
If your organization requires a more comprehensive framework for managing, editing, and sharing parcel data in both a multiuser (ArcGIS Enterprise) and single-user environment, consider using the parcel fabric.