Navigation and Seamanship

1.1.3.4. Radio Navigation

                                                                                                     

            Radio navigation is the determination of position and to lesser extent, course direction using information gained from radio waves received and processed on board a vessel or aircraft. It uses radio waves to determine position by either radio direction finding systems or hyperbolic systems. Radar navigation also uses radar to determine the distance from or bearing of objects whose position is known, in addition to the collision avoidance system. Radar is ‘electronic piloting’ and the use of satellites is a unique application of radio waves. Radio navigation system in general provides coverage of a few hundred to many thousands of miles with accuracies from + 5 miles. Celestial navigation requires is simple and self contained but requires fair weather in order to observe heavens and horizons. Radio systems are generally usable regardless of the weather but are subject to power and equipment failures. Radio navigation systems are continually being improved by research and development; already the earlier systems are being phased out and replaced with improved versions or entirely new systems. In addition to the above four basic types, two more types of navigation described by few authors. They are,