Radar_AT2

The receiver

A defective duplexer will likely cause damage to which of the following radar components?

Antenna Beamwidth

A pulse radar's range resolution is a function of the transmitted pulsewidth, while azimuth resolution is a function of what?

492 (3 x 164) Minimum TGT seperation PW x 164

A radar set has a pulsewidth of 3 microseconds. In order for the operator to see two separate blips that are directly on the same line of bearing, what minimum distance must separate the targets?

Temperature, pressure, and vapor content

Although high frequency energy from a transmitter travels essentially in a straight line and a constant speed, refraction and speed change are known to occur. Which of the following atmospheric conditions cause this to happen?

Increase in minimum range and decrease in receiver sensitivity

An increase in recovery time of a radar set will cause which of the following results?

Heterodyning

Because of the difficulty in amplifying high-frequency signals received in most radar receivers, it is necessary to generate an intermediate-frequency signal by a process referred to by which of the following terms?

Fast moving targets

Continuous-wave Radar, which employs the Doppler effect, is best suited in detecting which of the following targets?

Range resolution of a radar system is the minimum resolvable seperation in range of two targets at the same bearing.

Define range resolution of a radar system.

Measuring the difference between the frequency of the returned signal and the frequency of the radiated signal

Frequency-modulated radars transmit a wave that is continuously varying from a fixed reference frequency. What frequency modulation is used, how is the target detected?

PRF (pulse repetition frequency)

Generally, the maximum range of pulse type radar is determined by what element?

2

How many slew controls are there with the APS-130 radar system?

Narrow with a sloping trailing edge

In addition to certain power considerations, the output pulse of a radar transmitter should possess which of the following characteristic shapes in order to present nearby targets on an indicator?

One beamwidth

In order for two targets at the same range to appear as two targets instead of one target on the radar's indicator, what minimum distance must separate the two targets?

Elevation

On a RHI display, what is represented by the vertical axis?

Range

On an A-scope presentation, what is displayed on the horizontal axis?

186,000 miles per second 162,000 nautical miles per second 300 million meters per second

RF energy travels through the air at approximately what speed?

Atmospheric conditions Quality of maintenance performed on the equipment Operator's knowledge of equipment capability

Radar performance is affected by which of the following factors?

Electromagnetic energy

Radar uses what form of energy to detect the presence of objects?

Radio Detection and Ranging

The Acronym Radar is derived from what words?

Pilot

The Azimuth Elevation Range Indicator IP-1060A/APQ-148 is locates at what station?

The gain Signal to noise ratio Converts the IF pulses to video pulses

The IF amplifier stages of a radar receiver determines which of the following receiver characteristics?

Target reception

The PRF of a radar must be low enough to eliminate ambiguous targets, but high enough that the antenna's speed of rotation does not interfere with what factor?

ECMO 1

The Radar Set Control C-10535/APS-130 (RCP) is located at which of the following stations?

Refraction

The bending of radar waves due to a change in density of the medium through which they are passing is known by what term?

PRT (pulse repetition time)

The elapsed time between the start of one transmitted pulse and the start of the next is known as which of the following terms?

Local Oscillator

The intermediate frequency is produced in what stage of a microwave receiver?

Peak Power

The maximum power of a RF transmitted pulse is referred to by what term?

Transmitted power, pulse repetition frequency (PRF), and receiver sensitivity

The maximum range of a pulse radar system depends upon what three factors?

Bunching

The process whereby some electrons are accelerated, some are decelerated, and others are unaffected in the movement of the electron beam towards the collector end of a klystron is referred to by what term?

15, 30, 75, 150

What are the four ranges on the PPI RNG rotary switch on the RCP?

RSG (Reference Signal Generator)

What component provides a crystal-controlled clock and digital timing loop to generate PRF trigger, sweep triggers, range markers, and precision range line signal?

The longer the pulsewidth, the greater the range capabilities of the radar.

What effect is achieved by increasing the length of a pulsewidth?

The pulsewidth of the transmitted pulse and the recovery time of the duplexer and the receiver

What factors determine the minimum range of a pulse radar system?

PRT = 1/PRF

What is the formula for calculating PRT?

PRF = 1/PRT

What is the formula for calculating the PRF?

Pavg = Ppk x PW/PRT

What is the formula to calculate Pavg?

1,804 yards (10.5 + 0.5) x 164

What is the minimum range for a radar system with a pulsewidth of 10.5us, which has a recovery time of 0.5us?

To permit the use of one antenna for transmission and reception

What is the primary function of radar duplexing system?

To supply high voltage, rectangular pulses to drive the transmitter

What is the purpose of the modulator in a typical pulse radar system?

30 nautical miles

What is the range of target when the elapsed time for the radar pulse to travel to the target and return is 370.8us. ?

185.4us (15 x 12.36)

What is the time required for two-way travel of an RF pulse if the target is 15 miles from the radar unit?

Pulse Forming Network (PFN)

What modulator circuitry determines the voltage level and width of the pulse generated?

IF amplifier/detector

What section of a radar receiver usually determines the overall bandwidth?

temperature inversion

What term is used to describe the situation in which atmospheric temperature first increases with altitude and then begins to decrease?

Synchronizer

Which of the following components of a radar system determines the timing for all components of the radar?

Ducting

Which of the following conditions is formed by a temperature inversion and/or by a moisture lapse that may extend or reduce the range of radar?

Duty Cycle = PW x PRF

Which of the following formulas expresses the duty cycle of a radar set?

Pulse Modulation

Which of the following methods of transmitting RF energy uses the Doppler principle of radar detection?

PPI

Which of the following radar displays provides a map-like presentation that is practically an exact replica of the region scanned by the radar antenna?

Peak power is expended during the transmission of a pulse, and average power is the power expended over the pulse repetition time

Which of the following statements is correct concerning peak power and average power of a pulsed radar system?

Altitude difference must be considered if horizontal range is to be computed.

Which of the following statements is correct concerning the slant range as used to indicate a target's distance from an observing radar?

Klystron

Which of the following tubes should be used as the power amplifier in a radar transmitter?