Antenna tracking system
Encyclopedia
An antenna tracking system tracks a primary antenna to follow a moving signal source, such as a communication satellite. A secondary antenna has a greater beam width than the primary antenna and receives the same tracking signal
Tracking signal
In statistics and management science, a tracking signal signal monitors any forecasts that have been made in comparison with actuals, and warns when there are unexpected departures of the outcomes from the forecasts...

 from the satellite. The primary antenna is tracked according to a predetermined search pattern which causes a variation in the signal amplitude depending upon the relative location of the satellite and the antenna position. The signal strength signals from the two antennas are input to a summation function which takes the difference of the two signals. The noise and signal variation component of the two signals is substantially the same and is therefore eliminated from the resulting difference signal. An antenna control unit utilizes the resulting difference signal to select the optimum signal strength
Signal strength
In telecommunications, particularly in radio, signal strength refers to the magnitude of the electric field at a reference point that is a significant distance from the transmitting antenna. It may also be referred to as received signal level or field strength. Typically, it is expressed in...

 for the particular step of the search pattern. This system is particularly applicable to high frequency communication channels in the higher (86 Ghz and above) frequency band which are subject to atmospheric distortion and noise.
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