Q1. Radar surface-angular measurements are referenced to true north and measured in what plane?
A1. Horizontal plane.
The distance from a radar set to a target measured along the line of sight is identified by what term?
Q3. What is the speed of electromagnetic energy traveling through air?
A3. Approximately the speed of light (162,000 nautical miles per second).
How much time is required for electromagnetic energy to travel 1 nautical mile and return to the source?
A4. 12.36 microseconds.
Q5. In addition to recovery time, what determines the minimum range of a radar set?
A5. Pulse width.
Atmospheric interference with the travel of electromagnetic energy increases with what rf energy characteristic?
Q7. How is prt related to prf?
Q8. What type of radar transmitter power is measured over a period of time?
A8. Average power.
Q9. What term is used to describe the product of pulse width and pulse-repetition frequency?
A9. Duty cycle.
Q10. What type of target bearing is referenced to your ship?
A10. Relative bearing.
Q11. What type of radar detects range, bearing, and height?
Q12. What characteristic(s) of radiated energy is (are) altered to achieve electronic scanning?
A12. Frequency or phase.
What term is used to describe the ability of a radar system to distinguish between targets that are close together?
A13. Target resolution.
Q14. The degree of bearing resolution for a given radar system depends on what two factors?
A14. Beam width and range.
What happens to the speed of electromagnetic energy traveling through air as the altitude increases?
A15. Speed increases.
What term is used to describe a situation in which atmospheric temperature first increases with altitude and then begins to decrease?
What radar subsystem supplies timing signals to coordinate the operation of the complete system?
When a transmitter uses a high-power oscillator to produce the output pulse, what switches the oscillator on and off?
A18. High-voltage pulse from the modulator.
Q19. What radar component permits the use of a single antenna for both transmitting and receiving?
Q20. What is the simplest type of scanning?
A20. Single lobe.
How does the operator of a single-lobe scanning system determine when the target moves off the lobe axis?
A21. The reflected signals decrease in strength.
Q22. What are the two basic methods of scanning?
A22. Mechanical and electronic.
Q23. Rotation of an rf-feed source to produce a conical scan pattern is identified by what term?
Q24. The Doppler effect causes a change in what aspect of rf energy that strikes a moving object?
Q25. The Doppler variation is directly proportional to what radar contact characteristic?
Q26. The Doppler method of object detection is best for what type objects?
A26. Fast-moving targets.
Q27. The beat frequency in a swept-frequency transmitter provides what contact information?
What factor determines the difference between the transmitted frequency and the received frequency in an fm transmitter?
A28. Travel time.
Q29. What type of objects are most easily detected by an fm system?