Creating features using the geometry in a standard message

Mapping message control points to geometry in ArcGIS military features

Standard military messages contain information about the feature's location on the earth. To place the feature in the map, the x,y values for the geometry must be set based on the values contained in the message. If the values in the message are lat/long WGS-84, they can be used directly. If they are not, the coordinate values need to be converted using the Convert Coordinate Notation tool prior to being used. Point features from messages can be placed by a user using the coordinate values contained in the message. For some line and area features, however, the control points in the message do not represent the feature geometry. In these cases, the control points are instructions about the orientation, positioning, and size of the symbol. In cases when the control points do not represent the feature geometry, control points need to be translated into feature geometry and symbol overrides. For example, consider the control points of a ground supporting attack arrow.

For a ground supporting attack arrow message, assume the message has control points numbered as point 1 through point N. Control point 1 of the arrow represents the tip of the arrow. Control points 2 through point N-1 represent the rest of the shape of the arrow body, where point N-1 is the last point on the body of the arrow. Control point N is then used to represent left tip of the arrow head as you are looking in the direction the arrow is pointing. The valuable piece of information that point N adds to the message is the width of the arrow, or the offset from the imaginary center line of the arrow body.

ArcGIS military features use geometry to represent the arrow in a different manner. ArcGIS military features use a line geometry with vertices that correspond inversely to the control points in the message. Point N-1 is taken from the message and used as the point to start drawing from the tail end of the arrow. In this manner, point N-1 translates to ArcGIS military features as the first vertex of a line geometry, point N-2 translates to ArcGIS military features as line vertex 2, and so on, until point 1 from the message, which translates to the last ArcGIS military features line vertex, the tip of the arrow at point 3. The width of the arrow, that was controlled by another control point (N) in the message, is controlled by ArcGIS military features using a default offset to each side of the geometry. You can make the arrow body wider by changing the width of the representation, either by changing the representation rule for the feature, or by using overrides on the representation.