Definition of Horizontal Angle: a) An angle between any two points within the same horizontal plane.
Definition of Horizontal: a) parallel to the plane of the horizon; level; flat. b) at right angles to the vertical; parallel to level ground.
This calculation is possible when you integrate any of LTI's laser rangefinders with a MapStar TruAngle. Once you zero out the TruAngle in any direction, it will calculate the horizontal angle up to 359.9 degrees in either direction until you fire the laser towards another target. Combining the rangefinders' distance and vertical inclination values with this horizontal angle allows for complete 3D positioning that can be integrated with GPS for remote offset mapping.