dead reckoning

dead reckoning:

see navigation.

Dead Reckoning

 

the continuous calculation of the elements of a vessel’s course, such as speed and direction, and the effects of external forces in order to determine the vessel’s coordinates without observation of orientation points on shore or of heavenly bodies. The accuracy of dead reckoning is sufficient for keeping a vessel on the course set and for ensuring navigational safety. The quantities used are the ship’s heading and speed and the drift vector. When dead reckoning is performed on a map, the true course, distances traveled, and the ship’s turning trajectory and drift are calculated and plotted. The use of automatic position plotters in such dead reckoning permits continuous calculation of the vessel’s position; when dead reckoning is done by hand, positions are calculated sequentially at discrete time intervals. Analytic techniques for dead reckoning require the use of calculators.

dead reckoning

[¦ded ′rek·ən·iŋ]

(navigation)

Determination of position of a craft by advancing a previous position to a new one on the basis of assumed distance and direction traveled.

dead reckoning (DR)

In navigation, determination of position by advancing a previous known position using courses and distances. This navigational technique employs direct computation, using the triangle of velocities, from which the ground speed can be calculated and the course to steer can be determined. It is also a method of finding one's position by means of a compass and calculations based on speed, time elapsed, effects of wind, and direction from a known position.

dead reckoning

a method of establishing one's position using the distance and direction travelled rather than astronomical observations