Radio navigation
The term radio navigation summarizes methods for (terrestrial) navigation that use radio waves to determine position . This is to be distinguished from satellite navigation methods , which, however, also use radio waves . Radio navigation is generally based on transmitter stations that send out signals with the help of which a receiver can determine its position .
A distinction can be made between distance methods and direction finding methods .
- In the distance method , either the distance to a transmitting station ( DME ) or the difference in distance between two transmitting stations is determined by hyperbola navigation . The receiver can determine its position relative to the transmitting stations from the signal transit times or the differences in the signal transit times. Since the positions of the transmitting stations are known, the geographic position can be derived from them. Since the signals from only two transmitting stations result in several possibilities for the calculated position, which are located on a hyperbola (hence the name hyperbolic method), at least three stations are required. Distance methods are used in GLONASS and GPS , hyperbolic methods in the navigation systems LORAN-C and ALPHA .
- With the DF method , the direction of origin of a signal is determined.
Either the signal from the transmitter is transmitted in a direction-coded manner (e.g. rotating radio beacon , for short VOR) or the receiver must use a DF antenna to determine the direction of origin to a non-directional radio beacon (NDB). A radio compass targets the transmitter whose frequency is set. The instrument in the vehicle shows the angle between the longitudinal axis of the vehicle and the direction in which the targeted transmitter is located ( radio position line ) ( radio lateral direction finding ). If you determine the directions of two transmitting stations, you can deduce your position from it ( cross bearing ).
With radio navigation or radio localization, the radio signal can be used by measuring and then evaluating various components:
- Field strength (e.g. the field strength of several WLAN access points - WLAN-based location )
- Direction (Engl. Direction of arrival , DOA)
- running time
- Delay (Engl. Time (difference) of arrival , T (D) OA)
Today radio navigation systems are particularly important in aviation and shipping .
Satellite-based navigation systems ( GPS and others) were originally e.g. T. designed for the military. They have gained in importance for driving, cycling and hiking.
The Autonomous driving is absolutely dependent on radio navigation.
Also driverless transport systems often use radio navigation with local radio beacons.
Unlike normal navigation maps pointing right are aligned, giving radio navigation map the routes described there as ill-looking courses over ground (Engl. Magnetic track ) on. The reason for this is that no true gyrocompasses are used in aircraft, so that all instruments (except GPS) are ultimately based on the magnetic magnetic compass. If all courses and bearings in the radio navigation are given uniformly misleading, the courses no longer need to be converted, which eliminates a potential source of error.
The following symbols are used on radio navigation cards to identify radio navigation systems:
| Navigation system | symbol |
|---|---|
| NDB |
|
| IN FRONT |
|
| VORTAC |
|
| TACAN |
|
| VOR / DME |
|
Long haul
Long-range navigation systems are usually used in shipping.
- alpha
- CHAYKA (Soviet equivalent to LORAN-C )
- Consol (out of order)
- Decca (out of service at least in Europe)
- LORAN-C
- OMEGA (out of service)
Short haul
Short-range navigation systems are used in aviation and are used there as a navigation aid, for example for landing . One differentiates:
- Distance measuring device (DME)
- Rotary beacon (VOR and DVOR )
- Instrument Landing System (ILS)
- Microwave Landing System (MLS)
- RSBN (roughly translated: radio system for local navigation)
- Tactical Air Navigation (TACAN)
- Non-directional radio beacon (NDB) / radio compass (ADF)
Satellite based
The satellite navigation systems use radio transmitters on artificial earth satellites that are received by the navigation device. In satellite navigation, radio waves are also used to determine position. The following systems are named:
See also
literature
- Peter Dogan: The Instrument Flight Training Manual. As developed by Professional Instrument Courses. 3rd edition, revised printing. Aviation Book Co., Seattle WA 2004, ISBN 0-916413-26-8 .
- Wolfgang Kühr: The private pilot. Volume 3: Technology II. 4th revised edition. Schiffmann, Bergisch Gladbach 1983, ISBN 3-921270-09-X .
- Jürgen Mies: Radio navigation. 2nd Edition. Motorbuch-Verlag, Stuttgart 1999, ISBN 3-613-01648-6 ( private pilot library 3).
- Jeppesen Sanderson : Private pilot FAA practical test study guide. Aairplane single-engine land. Jeppesen Sanderson, Englewood CO 2000, ISBN 0-88487-265-3 .
- Jeppesen Sanderson: Private Pilot Manual. Jeppesen Sanderson, Englewood CO 2001, ISBN 0-88487-238-6 .
- Wilhelm Thaller: Never Get Lost. Interpretation of radio navigation. (Horizontal situation indicator, radio magnetic indicator, holding). 2nd Edition. Thaller, Mondsee 2005, ISBN 3-00-007179-2 .
- Walter Air: CVFR textbook . Mariensiel 2001.
Web links
- Some historical and technical aspects of radio navigation in Germany from 1907 to 1945 (English; PDF file; 1.03 MB)
- Free test version of the navigation simulator for the book by Wilhelm Thaller, see literature (English / German; setup file; 15 MB)
- Free trial version - Navigation simulators VOR, HSI, LOC, RMI, ADF, DME & Wind Effect (setup file; about 5 MB)