| Popis: |
Wireless communication technologies use the radio waves to transfer information between two or more devices that communicate. Propagation of electromagnetic waves through free space can be used for communication or for positioning and navigation. One of the basic principles of the device for positioning, which works on the basis of receiving and transmitting radio waves, is the measurement of time of propagation of electromagnetic waves. Device transmits electromagnetic pulse of certain strength and duration in the free space, on the basis of the reflected echo of the same pulse (e.g. time delay, signal strength) the parameters of the target are determined. Parameters of target may be its distance, azimuth, elevation, and information on the movement of the target (speed, direction of movement). In some cases it is possible to determine the type of target, for example, what kind of flying objects is moving. In general, it can be said that the problem of radiolocation can be reduced to measurement of the distance between multiple wireless terminals participating in the position measurement. The need for the location of wireless terminals is growing due to the large number of applications that benefit from such information (military purposes, industry, medicine, commercial services). |
