8-D-38: Miscellaneous
8-38D1:
The heading flash is a momentary intensification of the sweep line on the PPI presentation. Its function is to:
Inform the operator of the dead-ahead position on the PPI scope.
Alert the operator when a target is within range.
Alert the operator when shallow water is near.
Inform the operator when the antenna is pointed to the rear of the ship.
8-38D2:
The major advantage of digitally processing a RADAR signal is:
Enhancement of weak target returns.
Digital readouts appear on the RADAR display.
An improved operator interface.
Rectangular display geometry is far easier to read on the CRT.
8-38D3:
In order to ensure that a practical filter is able to remove undesired components from the output of an analog-to-digital converter, the sampling frequency should be:
Greater than two times the highest component of the sampled frequency.
The same as the lowest component of the analog frequency.
Two times the highest component of the analog frequency.
The same as the highest component of the sampled frequency.
8-38D4:
Bearing resolution is:
The ability to distinguish two adjacent targets of equal distance.
The ability to distinguish two targets of different distances.
The ability to distinguish two targets of different elevations.
The ability to distinguish two targets of different size.
8-38D5:
The output of an RC integrator, when driven by a square wave with a period of much less than one time constant is a:
Triangle wave.
Sawtooth wave.
Sine wave.
Series of narrow spikes.
8-38D6:
How do you eliminate stationary objects such as trees, buildings, bridges, etc., from the PPI presentation?
Use a discriminator as a second detector.
Remove the discriminator from the unit.
Calibrate the IF circuit.
Calibrate the local oscillator.
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Color key:
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● = Unseen
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● = Weak
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● = Review
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● = Learned
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● = Incorrect answer
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