Radar guideness system Essay Example | Topics and Well Written Essays - 3750 words

Radar guideness system - Essay Example The signal processor contains a comparator which transforms one of the signals that have been divided, into a constant output. The signal processor has a track-and-hold arrangement that connects the delayed leading side of the output from the comparator with the other of the divided signals in order to locate a point of intersection between them. The point of intersection is a quantized amount of the delay sample for a given echo signal which indicates the mean weighted reflectivity value of an annulus of one or more different and random features selected before, about a pulse-impacted track point. The master processor integrates a sequence of delay samples into a simple data array and then compares the sample array with a range of data arrays of a stored data matrix at a particular altitude of the aircraft for the determination of the  flight path  of aircraft. Based on the  demands  of the signal processor, a Doppler filter may be incorporated (Siouris, p 59). Electromagnetic waves are produced when we induce changes in the form of oscillations, in a magnetic or electric field. The  waves then propagate outward at the speed of light-3.108 m/sec. The rate at which the oscillation takes place in turn determines the wavelength, according to the relationship For the practical purposes, if the intension is to create directional paths of these waves, we must use a wavelength that is shorter than the dimensions of the antenna used. An antenna is a device which receives or radiates electromagnetic waves. The current radar applications involve wavelengths of the order of 1 metre down to centimeters. This corresponds to frequencies from 1 GHz (109 cycles/sec) to around 60 GHz which are classified as the microwave band (Siouris, p 119). The term radar is an acronym for Radio Detection And Ranging. Radar is made up of two primary subsystems - a receiver and a transmitter. A transmitter is a device that produces a microwave signal that is usually modulated by pulsing