EW300 NAVAL WEAPON SYSTEMS - FINAL EXAM
Select all the FUNCTIONS of a weapon system: - Answer -Target Detection
Localization
Classification
Tracking
Weapon Selection
Neutralization
Wave Propagation Velocity is equal to: - Answer -wavelength multiplied by frequency
Match: Reflection - Answer -When an EM wave strikes a surface and bounces off it
Match: Diffraction - Answer -The tendency of EM waves to spread out, or bend around
objects
Match: Refraction - Answer -EM wave passes into a medium with a different speed of
propagation and the wave bends
Match: Interference - Answer -The property by which EM waves superimpose and their
energies combine when overlapping
Which of the following result in enhanced cross range resolution? - Answer -decreasing
range to target
increasing frequency
increasing antenna size
Two waves that are exactly 180 degrees out of phase will achieve [ blank ] interference.
- Answer -Destructive
T/F: Cross Range Resolution is used in comparision with distance of contacts at depth
(along same bearing and altitude) in order to determine whether they will be seen as
separate contacts on a RADAR PPI display based on the RADAR's PW and PCR -
Answer -False
Frequency is equal to: - Answer -wave propagation velocity divided by wavelength
In the radio wave portion of the Electromagnetic spectrum, absorption generally [ a ] as
frequency [ b ]? - Answer -a. increases
b. increases
When dealing with a Basic Pulse RADAR, the Duty Cycle (DC) is equal to which of the
following: (select all that are true) - Answer -- Pulse Width multiplied by the Pulse
Repetition Frequency
- Average Power divided by the Peak Power
,- Pulse Width divided by the Pulse Repetition Time
A difference in starting point between two EM waves is a difference in: - Answer -phase
angle
Which of the following must be true to resolve a single target from a group? - Answer --
Cross range resolution (azimuth and elevation) must be less than actual distance
between targets at the same range.
- Range resolution must be less than distance between actual targets at the same
bearing and altitude
What type of interference occurs when EM waves interact with one another and the
resultant wave increases in amplitude? - Answer -Constructive
Pulse Width (PW) - Answer -the active transmit time or duration of the electromagnetic
pulse.
Rest Time (RT) - Answer -the non-transmit time or the interval between
electromagnetic pulses
Pulse Repetition Time (PRT) - Answer -the total time for one transmission cycle.
Pulse Repetition Frequency (PRF) - Answer -number of pulses transmitted per second.
Average Power (PAVG) - Answer -the mean power transmitted over the entire cycle.
Peak Power (PPK) - Answer -the maximum power transmitted by a RADAR.
Duty Cycle (DC) - Answer -a ratio that represents the time that the transmitter is on to
one complete cycle of operation.
Range Resolution (RRES) - Answer -the minimum 'RANGE' between two targets on
the same bearing that the RADAR system is able to distinguish as two separate targets.
Cross Range Resolution (RCROSS) - Answer -the minimum 'ANGULAR
SEPARATION' between two targets at the same range that the RADAR system is able
to distinguish as two separate targets.
Beamforming can be achieved by which two means? - Answer -- Antenna array
- Quasi-optical reflectors
Electromagnetic wave energy is attenuated due to [ a ], [ b ], and [ c ] - Answer -a.
absorption
b. scattering
c. spreading
, Select the two types of antenna polarization: - Answer -- Linear (Vertical & Horizontal)
- Circular
Select the key components that make up a basic Pulsed RADAR system. - Answer -
Single Antenna
Receiver
Transmitter
Duplexer
Which of the following attributes pertain to a continuous wave RADAR system? -
Answer -- Displays contact relative velocity
- Uses the principle of Doppler Shift to compare received frequency to transmitted
frequency
- Simultaneously transmits and receives radio waves
T/F: One of the fundamental differences between Basic Continuous Wave (CW) and
Basic Pulsed RADAR is that Basic CW computes contact's relative speed. - Answer -
True
RADAR Cross Section - Answer -target's effective area that reflects RADAR energy
Noise - Answer -generated internally and externally, creating false returns
Threshold Level - Answer -chosen signal level above which a contact is displayed
Pulse Width - Answer -determines range resolution and min range
Smin - Answer -weakest possible signal that could still yield a valid return
Antenna Aperture - Answer -effective area of RADAR's transmitter/receiver of energy
Scan Rate - Answer -how fast the antenna is rotated
Beamwidth - Answer -half power (and greater) width of antenna beam
Directive Gain - Answer -antenna's ability to concentrate energy in the beam
PRF - Answer -determines max unambiguous range
Which of the following are true regarding phased array antennas? - Answer --
Broadside arrays are designed to create constructive interference along the boresight
- A 2-D array is required to focus a beam in both azimuth and elevation
Relative to mechanically steered arrays, select advantages of electronically steered
arrays. - Answer -- Instantaneous beam positioning
- Less moving parts
Select all the FUNCTIONS of a weapon system: - Answer -Target Detection
Localization
Classification
Tracking
Weapon Selection
Neutralization
Wave Propagation Velocity is equal to: - Answer -wavelength multiplied by frequency
Match: Reflection - Answer -When an EM wave strikes a surface and bounces off it
Match: Diffraction - Answer -The tendency of EM waves to spread out, or bend around
objects
Match: Refraction - Answer -EM wave passes into a medium with a different speed of
propagation and the wave bends
Match: Interference - Answer -The property by which EM waves superimpose and their
energies combine when overlapping
Which of the following result in enhanced cross range resolution? - Answer -decreasing
range to target
increasing frequency
increasing antenna size
Two waves that are exactly 180 degrees out of phase will achieve [ blank ] interference.
- Answer -Destructive
T/F: Cross Range Resolution is used in comparision with distance of contacts at depth
(along same bearing and altitude) in order to determine whether they will be seen as
separate contacts on a RADAR PPI display based on the RADAR's PW and PCR -
Answer -False
Frequency is equal to: - Answer -wave propagation velocity divided by wavelength
In the radio wave portion of the Electromagnetic spectrum, absorption generally [ a ] as
frequency [ b ]? - Answer -a. increases
b. increases
When dealing with a Basic Pulse RADAR, the Duty Cycle (DC) is equal to which of the
following: (select all that are true) - Answer -- Pulse Width multiplied by the Pulse
Repetition Frequency
- Average Power divided by the Peak Power
,- Pulse Width divided by the Pulse Repetition Time
A difference in starting point between two EM waves is a difference in: - Answer -phase
angle
Which of the following must be true to resolve a single target from a group? - Answer --
Cross range resolution (azimuth and elevation) must be less than actual distance
between targets at the same range.
- Range resolution must be less than distance between actual targets at the same
bearing and altitude
What type of interference occurs when EM waves interact with one another and the
resultant wave increases in amplitude? - Answer -Constructive
Pulse Width (PW) - Answer -the active transmit time or duration of the electromagnetic
pulse.
Rest Time (RT) - Answer -the non-transmit time or the interval between
electromagnetic pulses
Pulse Repetition Time (PRT) - Answer -the total time for one transmission cycle.
Pulse Repetition Frequency (PRF) - Answer -number of pulses transmitted per second.
Average Power (PAVG) - Answer -the mean power transmitted over the entire cycle.
Peak Power (PPK) - Answer -the maximum power transmitted by a RADAR.
Duty Cycle (DC) - Answer -a ratio that represents the time that the transmitter is on to
one complete cycle of operation.
Range Resolution (RRES) - Answer -the minimum 'RANGE' between two targets on
the same bearing that the RADAR system is able to distinguish as two separate targets.
Cross Range Resolution (RCROSS) - Answer -the minimum 'ANGULAR
SEPARATION' between two targets at the same range that the RADAR system is able
to distinguish as two separate targets.
Beamforming can be achieved by which two means? - Answer -- Antenna array
- Quasi-optical reflectors
Electromagnetic wave energy is attenuated due to [ a ], [ b ], and [ c ] - Answer -a.
absorption
b. scattering
c. spreading
, Select the two types of antenna polarization: - Answer -- Linear (Vertical & Horizontal)
- Circular
Select the key components that make up a basic Pulsed RADAR system. - Answer -
Single Antenna
Receiver
Transmitter
Duplexer
Which of the following attributes pertain to a continuous wave RADAR system? -
Answer -- Displays contact relative velocity
- Uses the principle of Doppler Shift to compare received frequency to transmitted
frequency
- Simultaneously transmits and receives radio waves
T/F: One of the fundamental differences between Basic Continuous Wave (CW) and
Basic Pulsed RADAR is that Basic CW computes contact's relative speed. - Answer -
True
RADAR Cross Section - Answer -target's effective area that reflects RADAR energy
Noise - Answer -generated internally and externally, creating false returns
Threshold Level - Answer -chosen signal level above which a contact is displayed
Pulse Width - Answer -determines range resolution and min range
Smin - Answer -weakest possible signal that could still yield a valid return
Antenna Aperture - Answer -effective area of RADAR's transmitter/receiver of energy
Scan Rate - Answer -how fast the antenna is rotated
Beamwidth - Answer -half power (and greater) width of antenna beam
Directive Gain - Answer -antenna's ability to concentrate energy in the beam
PRF - Answer -determines max unambiguous range
Which of the following are true regarding phased array antennas? - Answer --
Broadside arrays are designed to create constructive interference along the boresight
- A 2-D array is required to focus a beam in both azimuth and elevation
Relative to mechanically steered arrays, select advantages of electronically steered
arrays. - Answer -- Instantaneous beam positioning
- Less moving parts
