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These instruments are also used to measure the angular distance between objects: Octant, invented in 1731. The first widely accepted instrument that could measure an angle without being strongly affected by movement. Sextant, derived from the octant in 1757, eventually made all previous instruments used for the same purpose obsolete.
Nonius is a measuring tool used in navigation and astronomy named in honour of its inventor, Pedro Nunes (Latin: Petrus Nonius), [1] a Portuguese author, mathematician and navigator. The nonius was created in 1542 as a system for taking finer measurements on circular instruments such as the astrolabe .
For that reason, Admiral John Campbell, who conducted shipboard experiments with the lunar distance method, suggested a larger instrument and the sextant was developed. [ 10 ] From that time onward, the sextant was the instrument that experienced significant development and improvements and was the instrument of choice for naval navigators.
The instrument is most commonly used to measure the lengths of roads, rivers and other line features on maps. Opisometers designed for this purpose provide scales reading the measured distance in kilometers and miles.
To use the instrument, the course of the flagship was first set on the guide bar. When the initial and final stations had been set using the position bars, the speed ratio clamp was set to show the ratio of own ship speed to the speed of the flagship (if the flagship was doing 10 knots, and the manoeuvring ship had 15 knots available, the clamp ...
In aviation, distance measuring equipment (DME) is a radio navigation technology that measures the slant range (distance) between an aircraft and a ground station by timing the propagation delay of radio signals in the frequency band between 960 and 1215 megahertz (MHz). Line-of-visibility between the aircraft and ground station is required.
In Chinese navigation, the unit of jiao 角 is also used to represent a quarter 指 (an angle of 24 minutes 6 seconds). Due to the limited width of the card, the kamal was only really useful for measuring Polaris in equatorial latitudes, where Polaris remains close to the horizon. This fact may explain why it was not common in Europe.
An inertial navigation system (INS; also inertial guidance system, inertial instrument) is a navigation device that uses motion sensors (accelerometers), rotation sensors and a computer to continuously calculate by dead reckoning the position, the orientation, and the velocity (direction and speed of movement) of a moving object without the ...