Navigation
Navigation is the art of getting from one place to another, safely and efficiently.
I find it amazing that these navigators managed to get an aircraft to a position and then home again in all types of weather and with other people shooting holes in their aircraft. There is a documented case where a Lancaster was hit by enemy fire over Norway and all the navigation equiptment carried away. The navigator managed to get them to neutral Sweden by memory. See the true tales section for a story named Tonsberg Raid.
SHORT HISTORY OF NAVIGATION
The first record of boats large enough to carry goods for trade is around 3500 B.C. and this would mark the birth of the art of navigation.These first navigators stayed close to shore and navigated by sight of landmarks or land characteristics that they could see.
| When they did venture out of sight of land, the navigator was able to determine his latitude (north/south direction) by observing the height of the sun during the day and the North Star at night. |  |
| One of the earliest man-made navigation tools was the mariner’s compass, an early form of the magnetic compass (c.13th Century). Initially used only when the weather obscured the sun or the North Star, these first compasses were very crude. The navigator would rub an iron needle against a lodestone, stick it in a piece of straw and float it in a bowl of water. The needle would point in a northerly direction. Early mariners found the compass inconsistent – most likely because they did not understand that it pointed to the magnetic north pole, not true north (This is called variation). At the time, they could not explain these variations and could not put much trust in the readings when navigating an unknown area. |  |
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Mariners at this time also used the cross-staff and the astrolabe (c.1484 Martin Behaim) to measure the angle above the horizon of the sun and stars to determine latitude. The forerunner of the much more portable (and accurate) sextant, the astrolabe was used to measure the altitude of a sun or star. Heavy and clumsy, it was very difficult to use aboard a rolling ship, however, when new land was discovered and the astrolabe taken ashore, it was valuable in fixing the approximate latitude of the new discovery. |
| A major advance that made dead-reckoning much more accurate was the invention of the chip log (c.1500-1600). Essentially a crude speedometer, a light line was knotted at regular intervals and weighted to drag in the water. It was tossed overboard over the stern as the pilot counted the knots that were let out during a specific period of time. From this he could determine the speed the vessel was moving. Interestingly, the chip log has long been replaced by equipment that is more advanced but we still refer to miles per hour on the water as knots. Using the sun and the stars, the navigator knew his beginning and ending latitude – now he could determine the distance he had traveled to estimate his east/west position. |  |
| GEE was an advancement during WWII that enabled pilots to get a fix on their position. This was mainly usefull with in close range of the UK. As the bombers ranged further out from England the GEE was not available as an over the horizon type radr guidance system. |
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British physicist Robert Watson-Watt produced the first practical radar (radio detection and ranging) system in 1935. It is used to locate objects beyond the range of vision by projecting radio waves against them. Radar can determine the presence and range of an object, its position in space, its size and shape, and its velocity and direction of motion. In addition to its marine uses, it is also used for controlling air traffic, detecting weather patterns and tracking spacecraft. |
Now every one is aware of Global Positioning Satellites that were developed by the United States Defence Department in 1972.
