Radar and Navigational Aids

158 Pages·2015·9.1 MB·English

Radar and Navigational Aids
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Navigational Aids aj
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By V
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K. M. Vyas
DIET, Rajkot
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Introduction
• Navigation : The art of directing the
movements of a craft (object) from one point
to another along a desired path is called
navigation.
• Aids of navigation :
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• Compass T
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• Chronometer y
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• Sextant
• The Sun, The Moon, The Stars & The Winds
• The Theodolite & Charts (Maps of known
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world)
Introduction
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The Compass
Introduction
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The Chronometer
Introduction
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The Sextant
Introduction
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The Theodolite
Introduction
• Magellan circumnavigated the Globe in the
early sixteenth century with the aid of listed
instruments.
• In eighteenth century the Chronometer, a
very accurate clock, was produced. t
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• With the chronometer the navigator was E
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able to determine his longitude by noting V
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the transit time.
• Navigation became science as well as art.
• In twentieth century, electronics entered
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the field.
Introduction
• Time signals were broadcast by which the
Chronometers could be corrected
• Direction finders and other navigational aids
which enable the navigator to obtain a fix
using entirely electronic aids were t
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developed and came into extensive use E
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• Our aim is to study about all navigational V
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aids which employ electronics in some way
• To start with a brief account of other
methods of navigation
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Four Methods of Navigation
• Navigation requires the determination of the
position of the craft & the direction in which
it has to go to reach desired destination
• The currently used methods of navigation ot
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may be divided into four classes : E
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1. Navigation by Pilotage (or Visual Contact) M
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2. Celestial or Astronomical Navigation
3. Navigation by dead-reckoning
4. Radio Navigation
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Navigation by Pilotage
• In this method, the navigator fixes his
position on a map by observing known visible
landmarks
• For e.g., in air navigation when the ground is
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visible the navigator can see the principal aj
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features on the ground such as rivers, s
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coastlines, hills etc. and thereby fix his M
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position
• Even at night, light beacons, cities and towns
provide information about position of the
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craft