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As with most 2D radar displays, the output of the radio receiver was attached to the intensity channel to produce a bright dot indicating returns. In the A-scope a sawtooth voltage generator attached to the X-axis moves the spot across the screen, whereas in the PPI the output of two such generators is used to rotate the line around the screen.
The three types of noise jamming are spot, sweep, and barrage. Spot jamming or spot noise occurs when a jammer focuses all of its power on a single frequency. This overwhelms the reflection of the original radar signal off the targets, the "skin return" or "skin reflection", making it impossible to pick out the target on the radar display.
Radars are rarely used alone in a marine setting. A modern trend is the integration of radar with other navigation displays on a single screen, as it becomes quite distracting to look at several different screens. Therefore, displays can often overlay an electronic GPS navigation chart of ship position, and a sonar display, on the radar display ...
When a racon receives a radar pulse, it responds with a signal on the same frequency which puts an image on the radar display. This takes the form of a short line of dots and dashes forming a Morse character radiating away from the location of the beacon on the normal plan position indicator radar display. The length of the line usually ...
A plan position indicator (PPI) is a type of radar display that represents the radar antenna in the center of the display, with the distance from it and height above ground drawn as concentric circles. As the radar antenna rotates, a radial trace on the PPI sweeps in unison with it about the center point. It is the most common type of radar ...
In radar systems, the blip-to-scan ratio, or blip/scan, is the ratio of the number of times a target appears on a radar display to the number of times it theoretically could be displayed. [1] Alternately it can be defined as the ratio of the number of scans in which an accurate return is received to the total number of scans.
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Early radar systems typically operated on a single frequency, and could only change that frequency by changing internal electronics. Against these radars, it was possible to use conventional radio sets to send out signals on the same band, causing the radar display to be filled with noise whenever the antenna was pointed in the general ...