Prismatic compass

Soldier using a prismatic compass to get an azimuth

A prismatic compass is a navigation and surveying instrument which is extensively used to find out the bearing of the traversing and included angles between them, waypoints (an endpoint of the course) and direction.[1] Compass surveying is a type of surveying in which the directions of surveying lines are determined with a magnetic compass, and the length of the surveying lines are measured with a tape or chain or laser range finder.[2] The compass is generally used to run a traverse line. The compass calculates bearings of lines with respect to magnetic needle. The included angles can then be calculated using suitable formulas in case of clockwise and anti-clockwise traverse respectively. For each survey line in the traverse, surveyors take two bearings that is fore bearing and back bearing which should exactly differ by 180° if local attraction is negligible. The name Prismatic compass is given to it because it essentially consists of a prism which is used for taking observations more accurately.[3]

  1. ^ "What is a prismatic Compass?". wiseGEEK.com. Retrieved June 27, 2015.
  2. ^ "What is Prismatic compass survey?". CivilGuides. Retrieved June 27, 2015.
  3. ^ Dr. B.C Punmai (2005). Surveying Vol. 1. Firewall Media. ISBN 9788170088530. Retrieved 14 December 2014.