Search results
Results from the WOW.Com Content Network
Navigational instruments are instruments used by nautical navigators and pilots as tools of their trade. The purpose of navigation is to ascertain the present position and to determine the speed, direction , etc. to arrive at the port or point of destination.
Polynesian navigators used a range of tools and methods, including observation of birds, star navigation, and use of waves and swells to detect nearby land. Songs, mythological stories, and star charts were used to help people remember important navigational information.
Nautical charts are essential tools for marine navigation; many countries require vessels, especially commercial ships, to carry them. Nautical charting may take the form of charts printed on paper (raster navigational charts) or computerized electronic navigational charts. Recent technologies have made available paper charts which are printed ...
Navigation that follows a rhumb line — that is, all meridians are cut at the same angle. On a nautical chart following the Mercator projection, a loxodromic is represented by a straight line. This type of navigation is useful for not too long distances, as it allows the course to remain steady, [16] but it does not offer the shortest distance.
A navigation system on an oil tanker. Navigation [1] is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. [2] The field of navigation includes four general categories: land navigation, [3] marine navigation, aeronautic navigation, and space navigation. [1]
Most commonly used however (especially on merchant ships) is the electromagnetic log, more reliable as there is no mechanism subject to breakdown. In recent years ultrasonic speed sensors have become available. These use two ultrasonic transducers—one forward, one aft—that send ultrasonic pulses through the water flowing past the hull.
Skilled navigators can use the Moon, planets or one of 57 navigational stars whose coordinates are tabulated in nautical almanacs. Historical tools include a sextant , watch and ephemeris data. Today's space shuttle, and most interplanetary spacecraft, use optical systems to calibrate inertial navigation systems: Crewman Optical Alignment Sight ...
A modern military compass, with included sight device for aligning. A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with magnetic north.