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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.
In navigation the instrument is also called a cross-staff and was used to determine angles, for instance the angle between the horizon and Polaris or the sun to determine a vessel's latitude, or the angle between the top and bottom of an object to determine the distance to said object if its height is known, or the height of the object if its distance is known, or the horizontal angle between ...
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 ...
The frame of a sextant is in the shape of a sector which is approximately 1 ⁄ 6 of a circle (60°), [2] hence its name (sextāns, sextantis is the Latin word for "one sixth"). "). Both smaller and larger instruments are (or were) in use: the octant, quintant (or pentant) and the (doubly reflecting) quadrant [3] span sectors of approximately 1 ⁄ 8 of a circle (45°), 1 ⁄ 5 of a circle (72 ...
The time interval needs to be adjusted according to the distance between knots. Substituting 6,000 feet for 1 mile, the above formula yields 28.8 seconds for a distance of 8 fathoms. In fact, 28-second and 14-second glasses used to be common among navigation equipment. [9] Chip log in the 18th century
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.
Turns the aircraft so that the station is directly off one of the wingtips. Flies that heading, timing how long it takes to cross a specific number of NDB bearings. Uses the formula: Time to station = 60 × number of minutes flown / degrees of bearing change; Computes the distance the aircraft is from the station; time × speed = distance
Thomas Walker & Son were inventors and makers of nautical instruments in the 19th and 20th centuries. The firm made one of the most commonly used navigation instruments, the 'log' which allowed sailors to measure distance at sea, [1] [2] one of the main measurements used in nautical navigation. The firm was founded by Thomas Walker in ...