There is a device that is used to find the source of radio and this act is proved to very valuable to detect survivors. If two or more measurements are used form different location, then even an unknown transmitter can be determined.
What is the use?
There is a system that is known as radio detection finder which is used for radio navigation especially for boats and aircraft. This can be used almost with any radio source. The size of the receiver antennas has a function of the wavelength of the signal. This is usually used on the ground based systems.
- This is mostly used for marine navigation because they can travel for long distances. The journey is over the horizon and so this detection finder is very useful for ships. The system can detect the ships when the distance is few tens of kilometres.
- This is also a great system for aerial use where the horizon is expected to extend for hundreds of kilometres. The detection system is great for higher frequencies and that too with the use of smaller antennas.
- The automatic radio detection finder or transmitters are capable to be tuned to all the radio transmitters. This is feature that is available in almost all the aircrafts.
If you see, the military has been using this system over a long period of time. It is very beneficial to detect or locate the position of the enemy with the help of intelligence systems and methodologies. This is the ability to locate the position of the enemy and it is used since World War I.
You will see that this system has been used since many years and has improved with the development of technology. The difference with the old is that it had all mechanically rotated antennas that helped to compare the strength of the signal in different directions.