Radar Performance Testing & Monitoring Flashcards
7 cards from real CMRT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Radar Performance Testing & Monitoring flashcards as text
What is a 'blind sector' on a marine radar display?
Answer: An area of no radar coverage caused by an obstruction such as a mast or funnel
A blind sector is an area of the radar sweep where coverage is blocked by a physical structure on the vessel such as a mast, funnel, or superstructure, creating a gap in radar coverage.
During a radar performance test, what does a decrease in the signal-to-noise ratio indicate?
Answer: Degraded radar performance, possibly due to a weakening magnetron or increased receiver noise
A decrease in signal-to-noise ratio indicates degraded radar performance, often caused by reduced transmitter power from a weakening magnetron or increased internal noise in the receiver chain.
What is the purpose of a calibrated corner reflector during radar performance testing?
Answer: To provide a known radar cross-section target for range and sensitivity testing
A calibrated corner reflector provides a target with a precisely known radar cross-section, allowing technicians to verify range accuracy and receiver sensitivity against a consistent reference standard.
Bearing (azimuth) resolution of a marine radar is primarily determined by which parameter?
Answer: Horizontal beamwidth of the antenna
Bearing resolution is determined by the horizontal beamwidth of the antenna; a narrower beam allows the radar to distinguish two targets at the same range that are close together in azimuth.
How does switching to a longer range scale on a marine radar affect the transmitted pulse width?
Answer: The pulse width increases to improve detection of distant targets
At longer range scales, the radar automatically uses longer pulse widths to increase the energy per pulse, improving detection of distant targets at the expense of range resolution.
What is the IMO-specified maximum range error tolerance for marine navigational radar?
Answer: ±1% of the range scale in use or 30 meters, whichever is greater
IMO performance standards specify that range accuracy must be within ±1% of the range scale in use or 30 meters, whichever is greater, to ensure reliable distance measurements.
In radar performance testing, what does 'system sensitivity' refer to?
Answer: The minimum input signal level that the complete radar system can detect and display
System sensitivity is the minimum signal level at the antenna that the complete radar can detect and present on the display, representing the combined performance of both the transmitter and receiver subsystems.