This set of Radar Multiple Choice Questions & Answers (MCQs) focuses on “Moving Target Detector”.
1. Moving Target Detector is an example of ___________
a) Target recognition
b) Pulse Compression
c) Doppler effect
d) MTI processing
View Answer
Explanation: The Moving Target Detector (MTD) is an example of an MTI processing system that takes advantage of the various capabilities offered by digital techniques to produce improved detection of moving targets in clutter.
2. Out of the following examples, why was Moving Target Detector originally built for?
a) ASR
b) Space
c) Law enforcement
d) Ships
View Answer
Explanation: It was originally developed by the MIT Lincoln Laboratory for the Airport Surveillance Radar, a 60-nmi radar found at major airports for control of local air traffic. The introduction of MTD represented an innovative and significant advance in radar detection of aircraft in the presence of clutter.
3. In which band designation was the original MTD concept similar to FAA’s ASR-8 operated in?
a) S band
b) L band
c) C band
d) X band
View Answer
Explanation: The original MTD concept was designed for a radar similar to the FAA’s ASR-8, which operated at S band (2.7 – 2.9 GHz) with a pulse width of 0.6 µs, 1.35° azimuth beam width, antenna rotation rate of 12.8 rpm, average PRF of 1040 Hz and an average power of 875 W.
4. Alongside with an eight-pulse FFT digital filter bank, what else did the original MTD included?
a) Oscillator
b) Two pulse canceller
c) Three pulse canceller
d) Video amplifier
View Answer
Explanation: An eight-pulse FFT digital filter bank with eight filters is preceded by a three-pulse delay-line canceler. The three-pulse canceler reduced the dynamic range of the signals which the Doppler filter bank had to handle, and it compensated for the lack of adequate cancellation of stationary clutter in the Doppler filters.
5. Why was the MTI processor preceded by a large dynamic range receiver?
a) Avoid clutter noise
b) Avoid reduction in improvement factor
c) Avoid Doppler frequency
d) Avoid any range ambiguities
View Answer
Explanation: One of the biggest limitation of an MTI processor is that it has a poor reduction factor because of limiting which is much better in a large dynamic range receiver. There when the output was transmitted to I and Q phase detectors, the analog to digital converters helped in changing the analog signals to digital words.
6. What does CPI stands for?
a) Compound Processed Interval
b) Clutter Processing Interval
c) Coherent Processing Interval
d) Centroid Processed Interval
View Answer
Explanation: CPI stands for Coherent Processing Interval. The 10 pulses of the CPI are processed by an eight-pulse filter bank that is preceded by a three-pulse delay-line canceller. Changing the PRF every 10 pulses eliminated second time around clutter echoes that would normally degrade a conventional MTI using pulse to pulse stagger of the PRF.
7. A conventional MTI processor eliminates ____________
a) point clutter
b) volume clutter
c) surface clutter
d) stationary clutter
View Answer
Explanation: A conventional MTI processor eliminates stationary clutter. Not to mention it also eliminates aircraft moving on a crossing trajectory which causes the aircraft’s radial velocity to be zero. This is unfortunate since radar cross section of an aircraft is relatively large when viewed at the broadside aspect presented by a crossing trajectory.
8. Filter bank allows moving targets to be separated from moving clutter so that detection can take place.
a) True
b) False
View Answer
Explanation: It’s an advantage of a filter bank that allows moving targets to be separated from moving clutter so that detection can take place. Since the Doppler shifted radar echo from a moving target usually has a radial velocity greater than the maximum unambiguous velocity, its Doppler frequency can fold over into one of the eight filters of the filter bank.
9. Correlation and interpolation algorithms are not characteristics of second generation MTD.
a) True
b) False
View Answer
Explanation: Correlation and interpolation algorithm are characteristics of second generation MTD. They clustered the threshold crossings in range, azimuth, and Doppler to provide in a single report the best values of the radar observables of a single target, whether it be aircraft, automobile, or bird.
10. In the 3rd generation MTD, the first operational air-traffic control implementation of the MTD concept was for the __________
a) ASR-9
b) ASR-6
c) ASR-4
d) ASR-7
View Answer
Explanation: The first operational air-traffic control implementation of the MTD concept was for the ASR-9, a radar employed at the major airports of the United States and elsewhere in the world. It utilizes the basic philosophy of the second generation Lincoln Laboratory MTD and significant extensions by Westinghouse.
Sanfoundry Global Education & Learning Series – Radar.
To practice all areas of Radar, here is complete set of Multiple Choice Questions and Answers.
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