How can ARPA tracks remain valid when the ship changes heading?

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Multiple Choice

How can ARPA tracks remain valid when the ship changes heading?

ARPA tracks stay valid during a heading change because the system builds and updates target tracks in a frame that rotates with your vessel. The heading input tells ARPA how the radar’s bearing axis is oriented relative to true north, so when you turn, the track’s predicted position depends on the heading being current. If the own-ship heading feed is wrong or not updated, the extrapolated positions will drift and the tracks can become inaccurate. To keep tracks accurate, ensure ARPA is using the correct own-ship heading input from a reliable source (for example, the vessel’s gyro or heading sensor) and actively monitor that tracks are being updated as new radar data comes in. Repositioning the Electronic Bearing Line and the Visual Range Marker after a turn helps re-affirm the reference geometry, so measurements remain aligned with the updated heading and the target’s relative position is accurately maintained. Relying on turning ARPA off or on using AIS alone won’t guarantee continuous track validity, and repositioning EBL/VRM by itself doesn’t fix the underlying need for the correct heading input.

ARPA tracks stay valid during a heading change because the system builds and updates target tracks in a frame that rotates with your vessel. The heading input tells ARPA how the radar’s bearing axis is oriented relative to true north, so when you turn, the track’s predicted position depends on the heading being current. If the own-ship heading feed is wrong or not updated, the extrapolated positions will drift and the tracks can become inaccurate.

To keep tracks accurate, ensure ARPA is using the correct own-ship heading input from a reliable source (for example, the vessel’s gyro or heading sensor) and actively monitor that tracks are being updated as new radar data comes in. Repositioning the Electronic Bearing Line and the Visual Range Marker after a turn helps re-affirm the reference geometry, so measurements remain aligned with the updated heading and the target’s relative position is accurately maintained.

Relying on turning ARPA off or on using AIS alone won’t guarantee continuous track validity, and repositioning EBL/VRM by itself doesn’t fix the underlying need for the correct heading input.

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