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 symptom most commonly indicates a failing magnetron in a marine radar?
Answer: Decreased transmitter output power and progressively reduced detection range
A failing magnetron typically exhibits decreased transmitter output power, which directly results in reduced detection range and overall system sensitivity degradation over time.
Per SOLAS requirements, how often must a ship's radar be tested for proper operation?
Answer: Before each voyage and during each navigational watch as appropriate
SOLAS requires that navigational radar be tested for proper operation before each voyage and checked during watches as appropriate to ensure reliable target detection throughout the voyage.
What does a high noise figure in a radar receiver indicate?
Answer: Poor receiver sensitivity due to significant internally generated noise
A high noise figure indicates the receiver is adding significant internal noise to the signal, which degrades sensitivity and makes it harder to detect weak target returns against the noise background.
Which technique is used to verify the accuracy of a radar's heading marker alignment?
Answer: Comparing the radar heading marker against the ship's gyrocompass bearing
Heading marker accuracy is verified by comparing the radar's heading marker alignment with the heading provided by the ship's gyrocompass, ensuring both references agree within specified tolerances.
What information must be recorded in a ship's radar maintenance log?
Answer: Dates of tests, test results, faults found, and corrective actions taken
The radar maintenance log must record test dates, results, any faults or malfunctions found, and the corrective actions taken, providing a complete traceable service history for regulatory compliance.
A radar performance monitor showing a reduction of more than 4 dB from the established baseline typically indicates:
Answer: Significant performance degradation requiring technical investigation
A performance monitor reading that drops more than 4 dB from the established baseline indicates significant system performance degradation that warrants technical investigation and corrective action.
What is the function of Sensitivity Time Control (STC) in a marine radar receiver?
Answer: To reduce receiver gain for close-range returns in order to suppress sea clutter while maintaining target detection at longer ranges
Sensitivity Time Control (STC) applies a time-varying gain reduction to close-range returns to suppress strong sea clutter echoes, while allowing the receiver to operate at full sensitivity for more distant targets.