EW300 FINAL EXAM QUESTIONS + ANSWERS
1. A SAR antenna needs the antenna to be stationary and the target to
be moving.: False
2. A Synthetic Aperture Radar (SAR) achieves a large effective aperture by:: using
motion of the transmitter/receiver.
3. Electromagnetic wave energy is attenuated due to , ,
.: Spreading Scattering
Absorption
4. In the radio wave portion of the Electromagnetic spectrum, Attenuation gen-
erally as frequency ?: increases, increases
5. Pulse Width (PW): the active transmit time or duration of the electromagnetic pulse.
6. Rest Time (RT): the non-transmit time or the interval between electromagnetic pulses.
7. Pulse Repetition Time (PRT): the total time for one transmission cycle.
8. Pulse Repetition Frequency (PRF): number of pulses transmitted per second.
9. Average Power (PAVG): the mean power transmitted over the entire cycle.
10. Peak Power (PPK): the maximum power transmitted by a RADAR.
11. Duty Cycle (DC): a ratio that represents the time that the transmitter is on to one complete cycle of operation.
12. Range Resolution (RRES): the minimum range between two targets on the same bearing that the RADAR
system is able to distinguish as two separate targets.
13. Cross Range Resolution (RCROSS): the minimum angular separation between two targets at the
same range that the RADAR system is able to distinguish as two separate targets.
14. Beamforming can be achieved by which two means?: Antenna
array Quasi-optical reflectors
15. Which of the following result in enhanced cross range resolution?: Increasing
,antenna size
Increasing
frequency
decreasing
range to
target
16. Relative to mechanically steered arrays, select advantages of electronically
steered arrays.: Instantaneous beam positioning
Less moving parts
Can adjust beamwidth to cater towards search or fire control desires.
17. Basic Pulse RADAR: Detects bearing and range to target using a single antenna
, 18. Basic Contiunuous Wave RADAR: Detects bearing and relative velocity of target using 2 antennas.
19. Pulse Doppler RADAR: Detects bearing, range, and relative velocity of a target using a mixer and 1
antenna.
20. Frequency Modulated Continuous Wave RADAR (FMCW): Determines target bearing,
relative velocity, and range with 2 antennas and changing frequency over a given time period.
21. If unambiguous RADAR range is dictating maximum detection range for a
specific target, which of the following actions could an operator perform to
optimize radar performance in detecting that target?: Increase the Threshold Level to filter
noise
Decrease PRF to Increase Runamb
22. What type of interference occurs when EM waves interact with one another
and the resultant wave increases in amplitude?: Constructive
23. Look Ahead (Lecture 6): Which statements are true about threshold levels?-
: Decreasing the threshold level is likely to display more false
returns The threshold level can be adjusted manually
24. Moving Target Indicator (MTI): Measures changes in return signal phase to filter out stationary
targets.
25. Bandpass filter: Used by Doppler RADARs to filter contacts based on speed.
26. Pulse integration: The process of summing successive pulses along the same bearing in order to detect a
target.
27. Sensitivity Time Control (STC): Filters away surface-based environmental noise near the
RADAR system.
28. Fast Time Constant (FTC): Filters away atmospheric noise based on rate of change of return signals.
29. RADAR Cross Section: target's ettective area that reflects RADAR energy
30. Noise: generated internally and externally, creating false returns
31. Threshold Level: chosen signal level above which a contact is displayed
1. A SAR antenna needs the antenna to be stationary and the target to
be moving.: False
2. A Synthetic Aperture Radar (SAR) achieves a large effective aperture by:: using
motion of the transmitter/receiver.
3. Electromagnetic wave energy is attenuated due to , ,
.: Spreading Scattering
Absorption
4. In the radio wave portion of the Electromagnetic spectrum, Attenuation gen-
erally as frequency ?: increases, increases
5. Pulse Width (PW): the active transmit time or duration of the electromagnetic pulse.
6. Rest Time (RT): the non-transmit time or the interval between electromagnetic pulses.
7. Pulse Repetition Time (PRT): the total time for one transmission cycle.
8. Pulse Repetition Frequency (PRF): number of pulses transmitted per second.
9. Average Power (PAVG): the mean power transmitted over the entire cycle.
10. Peak Power (PPK): the maximum power transmitted by a RADAR.
11. Duty Cycle (DC): a ratio that represents the time that the transmitter is on to one complete cycle of operation.
12. Range Resolution (RRES): the minimum range between two targets on the same bearing that the RADAR
system is able to distinguish as two separate targets.
13. Cross Range Resolution (RCROSS): the minimum angular separation between two targets at the
same range that the RADAR system is able to distinguish as two separate targets.
14. Beamforming can be achieved by which two means?: Antenna
array Quasi-optical reflectors
15. Which of the following result in enhanced cross range resolution?: Increasing
,antenna size
Increasing
frequency
decreasing
range to
target
16. Relative to mechanically steered arrays, select advantages of electronically
steered arrays.: Instantaneous beam positioning
Less moving parts
Can adjust beamwidth to cater towards search or fire control desires.
17. Basic Pulse RADAR: Detects bearing and range to target using a single antenna
, 18. Basic Contiunuous Wave RADAR: Detects bearing and relative velocity of target using 2 antennas.
19. Pulse Doppler RADAR: Detects bearing, range, and relative velocity of a target using a mixer and 1
antenna.
20. Frequency Modulated Continuous Wave RADAR (FMCW): Determines target bearing,
relative velocity, and range with 2 antennas and changing frequency over a given time period.
21. If unambiguous RADAR range is dictating maximum detection range for a
specific target, which of the following actions could an operator perform to
optimize radar performance in detecting that target?: Increase the Threshold Level to filter
noise
Decrease PRF to Increase Runamb
22. What type of interference occurs when EM waves interact with one another
and the resultant wave increases in amplitude?: Constructive
23. Look Ahead (Lecture 6): Which statements are true about threshold levels?-
: Decreasing the threshold level is likely to display more false
returns The threshold level can be adjusted manually
24. Moving Target Indicator (MTI): Measures changes in return signal phase to filter out stationary
targets.
25. Bandpass filter: Used by Doppler RADARs to filter contacts based on speed.
26. Pulse integration: The process of summing successive pulses along the same bearing in order to detect a
target.
27. Sensitivity Time Control (STC): Filters away surface-based environmental noise near the
RADAR system.
28. Fast Time Constant (FTC): Filters away atmospheric noise based on rate of change of return signals.
29. RADAR Cross Section: target's ettective area that reflects RADAR energy
30. Noise: generated internally and externally, creating false returns
31. Threshold Level: chosen signal level above which a contact is displayed
