CMRT Navigation Integration & Display Systems Flashcards

What is the function of the Electronic Bearing Line (EBL) on a radar display?

Answer: Measures the bearing to a target from own ship

The EBL is a rotatable line from the vessel's position used to measure the bearing of a target or landmark on the radar display.

Which radar display feature is used to measure the distance to a target?

Answer: Variable Range Marker (VRM)

The Variable Range Marker (VRM) is a range ring that the operator adjusts to coincide with a target to read off the distance.

What is a radar 'guard zone' used for?

Answer: Alerting the watch when a target enters a defined area around the vessel

A guard zone is a user-defined sector or ring that triggers an alarm when a radar return enters it, warning of potential collision hazards.

What does TCPA stand for in ARPA radar systems?

Answer: Time to Closest Point of Approach

TCPA (Time to Closest Point of Approach) indicates how many minutes until a tracked target reaches its minimum distance from own ship.

In a radar display, what is the purpose of the 'rain clutter' (FTC) control?

Answer: Reduces large returns from precipitation to reveal targets within the rain

The Fast Time Constant (FTC) or rain clutter control differentiates rapid signal changes to suppress extended rain returns and reveal point targets within precipitation.

What interface standard is commonly used to connect radar processors to VDR (Voyage Data Recorder) systems?

Answer: NMEA 0183 or IEC 61162

NMEA 0183 and its successor IEC 61162 are the standard serial communication protocols used to interconnect bridge systems including radar and VDR.