This site is 100% ad supported. Please add an exception to adblock for this site.

Unit 5-3

Terms

undefined, object
copy deck
(812) Which timing generator module controls the off-line channel in the dual redundant receiver?
Off-line timing generator.
(812) What single dwell does the acquisition dwell replace when it is scheduled by the target data computer (TDC)?
Scan
(812) What is the total number of automatic alignment procedures to be performed by the timing generator during dead time?
Eight
(812) The fault threshold for both the LO and Transmitter drive outputs are set to indicate a fault at what level below the normal output level?
6 dB
(812) The non-coherent mode of operation is used to...
detect a target in the presence of moving clutter such as rain.
(813) What module in the dual redundant receiver determines the active channel of the receiver-processor based upon the test results?
Interface circuit card.
(813) In the dual redundant receiver, which of the following best describes the fault hierarchy for the automatic fault testing?

a. The test is randomly selected by the TDC.
b. The last module on the chain is tested first.
c. Modules
d. Modules that affect the testing of others are tested first.
(814) What is the output of the signal data converter (SDC) to the indicator group?
Unipolar video
(815) In single cancellation, what happens to the pulse train after it is time-aligned with the next range scan?
It subtracts the second range scan from the first.
(815) How many radar scans does double cancellation require?
Three
(815) What circuits identify and blank returns from targets beyond the operating range of the radar?
Second time around reduction circuits
[812] What are the timing generator's main functions?
To generate the radar timing, provide for fault isolation and alignment, and accommodate special tests under front panel control.
[812] When does the timing generator schedule automatic alignment and fault isolation?
During the 93 microseconds of dead time between the BCP and the first PRF trigger of each dwell.
[812] What does the on-line timing generator provide to the on-line REX and PAR system?
All timing and control signals to the on-line REX and PAR system.
[812] The frequency converter contains three crystal-controlled oscillators that are selected for XOA, XOB, and TRACK. These oscillators operate at what frequencies?
(1) 130.9575 MHz for XOA
(2) 132.2390 MHz for XOB
(3) 131.7917 MHz for the TRACK mode
[812] The IF down-converter combines the sum (S) with the delta azimuth (Da) and delta elevation (De) in quadrature to provide three outputs. For what are they used.
Track error
[812] What functions does the error detector perform during the track mode of operation?
It performs the filtering, limiting, phase detection, A/D conversion, decommutation, and integration of the azimuth and elevation signals.
[812] In the range track module each filter is 1.5 MHz wide and represents how many feet in predicted range?
6.25 feet in predicted range.
[813] Based upon what does the nonredundant interface determine the active channel of the receiver-processor?
The test results (of internal self alignment and fault monitoring circuits)
[813] What does the Channel Select Logic use the fault summary word for?
To determine the on-line channel.
[813] The reciever control panel is divided into what three functional areas?
Receiver status, special test, and test points.
[813] All of the switches in the special test section are disabled until enabled by the special test switch S4 with the exception of which switch?
The LIN/LIM switch.
[813] When is automatic fault isolation performed?
During the radar dead time.
[814] What is the time displacement of the input video channels to the SDC?
0.5 usec from each other.
[814] What is the destination of the canceled, unipolar video out of the Signal Data Converter (SDC)?
The shelter control indicator group and the radar data transfer group (RDTG).
[814] What are the three operational modes for the Signal Data Converter (SDC)?
(1) Digital Moving Target Indicator (DTMI) mode

(2) Digital Video Integration (DVI) mode

(3) Gated DVI mode
[815] Summarize the phase differences between a fixed and a moving target with respect to a radar echo.
The fixed target exhibits the same phase every return; the moving target will change phase every return.
[815] What is a major drawback of the single cancellation method?
The fixed targets are not always completely cancelled.
[815] How many scans are requred for successful double cancellation?
Three scans
[815] What is the purpose of video integration?
To enhance the weaker returns from longer range targets.
[815] What is the purpose of the second time around reduction circuitry?
To identify and blank returns from targets beyond the operating range of the radar (second-time-around clutter).

Deck Info

31

permalink