Term
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Definition
| The magnitude of the peak deviation from the average value of the disturbance. |
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Term
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Definition
| The distance between two identical points on adjacent waves. |
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Term
| As frequency increases, wavelength __________. |
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Definition
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Term
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Definition
| Angular argument at which sine wave begins. |
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Term
| What are the associated ground, sky, and space waves frequencies? |
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Definition
| Ground--30 Hz LF- 30Khz, Sky--30Khz - 30 MHz HF/MF, Space--Above 30 MHz VHF |
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Term
| What are 5 key points about pulse characteristics and RADAR performance? |
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Definition
1)Varying the pulse width effects the range of the radar.
2)Need short pulses for short range targets.
3)PW determines radar’s minimum range resolution.
4)The lower the PRF the greater the radar’s maximum range.
5)The higher the PRF the greater the radar’s accuracy. |
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Term
| What is two advantages of a shorter PW? |
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Definition
1)Better range resolution
2)Better detection of close targets (Better Min. Range) |
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Term
| What is one advantage of a longer PW? |
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Definition
More power => Longer detection range
(Better Max Range) |
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Term
| What is one advantage of a low PRF? |
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Definition
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Term
| What are two advantages of high PRF? |
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Definition
1)Increased probability of detection
2)More samples => Accurate |
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Term
| For a fire control radar, the beamwidth should be _____ and the PW should be _____. |
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Definition
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Term
| Why can’t a simple CW type radar measure range? |
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Definition
| No Transmitter “off time” to measure time until echo returned. |
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Term
| What is the main advantage of the CW type radar? |
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Definition
| “Sees” moving targets, continually updated. |
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Term
| How can the radar set be modified measure range? |
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Definition
| Frequency Modulating the wave allows for a time measurement - range. |
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Term
| Given an ideal fire control radar, for beam width, PRF, and PW state the level (high/low, short/long, wide/narrow) that would be used and WHY? |
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Definition
1)Beam Width: Narrow– better angular accuracy
2)PRF: High – more updates
3)PW: Short – Good range resolution and min range |
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Term
| What are the characteristics of a Pulse Radar? |
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Definition
1)Single Antenna
2)Gives Range & Bearing
3)Susceptible To Jamming
4)Physical Range Determined By PW and PRF. |
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Term
| What are the characteristics of a Continuous Wave Radar? |
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Definition
Requires 2 Antennae
1)No Range Info
2)High SNR
3)More Difficult to Jam But Easily
4)Deceived
5)Amp can be tuned to look for expected frequencies |
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Term
| What are the basic functions of an angle tracking servo system? |
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Definition
1)Sense position error magnitude and direction
2)Provide position feedback
3)Provide data smoothing /stabilization
4)Provide velocity feedback
5)Provide a power-driving device |
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Term
| What does negative feedback provide for a system? |
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Definition
| stability, reduction of error |
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Term
| What kinds of system responses are available in for feedback control? |
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Definition
| crit. damp., over/underdamped |
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Term
| What are the six functions of a track while scan system? |
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Definition
Target detection
Target track correlation and association
1)Target track initiation and track file generation (if a new target)
2)Generation of tracking “Gates”
3)Track gate prediction, smoothing and positioning
4)Display and future target calculations |
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Term
| What is an Acquisition Gate? |
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Definition
| Acquisition Gate: describes a (large) volume of space initially assigned when a new contact is gained by a TWS system. |
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Term
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Definition
| Tracking Gate: for the same contact, describes a progressively smaller volume of space. |
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Term
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Definition
| Turning Gate: TWS observes target maneuvering, before resolving back to Tracking Gate |
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Term
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Definition
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Term
| What are the three methods of beam steering? What is one advantage of each? |
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Definition
1)Time delay scanning-Allows greater flexibility of freq. utilization
2)Frequency scanning-Simple and inexpensive
3)Phase scanning-Most commonly used (better system) at a moderate cost |
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Term
| What are the limitations/difficulties associated with electronic scanning and phased array? |
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Definition
1)Element spacing
2)The suppression of the side lobe interference
3)Array element excitation amplitudes and geometry to achieve various beam radiation patterns
4)Combining the phased array with track-while-scan function
5)Modulating the radiated energy to transmit information (for missile guidance commands) |
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Term
| ___________ Conical scanning & monopulse are two different methods it uses. |
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Definition
| Angle Tracking Servo(ATS) |
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Term
| ____Can generate a computer tracking file based on a search radar input. |
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Definition
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Term
| _______Allows for instantaneous positioning of the radar beam within a sector. |
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Definition
| Electronic Steering/ Phased Array(ES/PA) |
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Term
| _____Is limited by the pattern and spacing of individual elements. |
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Definition
| Electronic Steering/ Phased Array(ES/PA) |
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Term
| _____Original system used to evaluate and reduce system error between the line of sight (LOS) & tracking line. |
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Definition
| Angle Tracking Servo(ATS) |
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Term
| _____Performs tracking through the use of various sized “gates”. |
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Definition
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Term
| _____Damping term used for this system, which produces a very smooth output but takes an unacceptably long time to do so. |
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Definition
| Overdamped Angle Tracking Servo(ATS) |
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Term
| _____Truly eliminates the wear, tear, and failure associated with a mechanical radar. |
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Definition
| Electronic Steering/ Phased Array(ES/PA) |
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Term
| _____System that provides velocity feedback using a tachometer for smoothing. |
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Definition
| Angle Tracking Servo(ATS) |
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Term
| _____First concept used to exploit the advantages of a search radar and fire control system working together. |
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Definition
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