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Doppler signals fall between 1.5 kHz, and 15 kHz, which is audible, so audio signals from medium-PRF radar systems can be used for passive target classification. For example, an L band radar system using a PRF of 10 kHz with a duty cycle of 3.3% can identify true range to a distance of 450 km (30 * C / 10,000 km/s). This is the instrumented ...
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.
The difference between the sample numbers where reflection signal is found for these two PRF will be about the same as the number of the ambiguous range intervals between the radar and the reflector (i.e.: if the reflection falls in sample 3 for PRF 1 and in sample 5 for PRF 2, then the reflector is in ambiguous range interval 2=5-3).
When the PRF of the "jamming" radar is very similar to "our" radar, those apparent distances may be very slow-changing, just like real targets. By using stagger, a radar designer can force the "jamming" to jump around erratically in apparent range, inhibiting integration and reducing or even suppressing its impact on true target detection.
The Hughes AN/ASG-18 Fire Control System was a prototype airborne radar/combination system for the planned North American XF-108 Rapier interceptor aircraft for the United States Air Force, and later for the Lockheed YF-12. The US's first pulse-Doppler radar, [4] the system had look-down/shoot-down capability and could track one target at a time.
The AN/AWG-9 and AN/APG-71 radars are all-weather, multi-mode X band pulse-Doppler radar systems used in the F-14 Tomcat, and also tested on TA-3B. [1] It is a long-range air-to-air system capable of guiding several AIM-54 Phoenix or AIM-120 AMRAAM missiles simultaneously, using its track while scan mode.
The second advantage of using an ASR-11 is the radar's ability to utilize a pulse sequence diversity. This gives the radar system the capability to limit processing dwells to a small number of pulses. This feature becomes most important when monitoring air traffic is the primary use of the radar.
The AN/FPS-117 is an L-band active electronically scanned array (AESA) 3-dimensional air search radar first produced by GE Aerospace in 1980 and now part of Lockheed Martin. [1] [2] The system offers instrumented detection at ranges on the order of 200 to 250 nautical miles (370 to 460 km; 230 to 290 mi) and has a wide variety of interference and clutter rejection systems.