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A civil marine radar, for instance, may have user-selectable maximum instrumented display ranges of 72, or 96 or rarely 120 nautical miles, in accordance with international law, but maximum unambiguous ranges of over 40,000 nautical miles and maximum detection ranges of perhaps 150 nautical miles. When such huge disparities are noted, it ...
Range and velocity can both be identified using medium PRF, but neither one can be identified directly. Medium PRF is from 3 kHz to 30 kHz, which corresponds with radar range from 5 km to 50 km. This is the ambiguous range, which is much smaller than the maximum range. Range ambiguity resolution is used to determine true range in medium PRF radar.
Range ambiguity resolution is a technique used with medium pulse-repetition frequency (PRF) radar to obtain range information for distances that exceed the distance between transmit pulses. This signal processing technique is required with pulse-Doppler radar .
This approach is used with the AN/SPS 49(V)5 Very Long Range Air Surveillance Radar, which sacrifices elevation measurement to gain speed. [9] Pulse-Doppler antenna motion must be slow enough so that all the return signals from at least 3 different PRFs can be processed out to the maximum anticipated detection range. This is known as dwell time ...
[1] [2] [3] This includes field of view in terms of solid angle and maximum unambiguous range and velocity, as well as angular, range and velocity resolution. Radar sensors are classified by application, architecture, radar mode, platform, and propagation window.
The maximum range of conventional radar can be limited by a number of factors: Line of sight, which depends on the height above the ground. Without a direct line of sight, the path of the beam is blocked. The maximum non-ambiguous range, which is determined by the pulse repetition frequency. The maximum non-ambiguous range is the distance the ...
Radar pulsing causes a phenomenon called aliasing, which occurs when the Doppler frequency created by reflector motion exceeds the pulse repetition frequency (PRF). [1] This concept is related to range ambiguity resolution. Doppler frequency shift is introduced onto reflected signals used by radar.
Pulse-Doppler ambiguity zones. Each blue zone with no label represents a velocity/range combination that will be folded into the unambiguous zone. Areas outside the blue zones are blind ranges and blind velocities, which are filled in using multiple PRF and frequency agility. The unambiguous zone is in the lower left corner.