Explain the difference between automatic and manual ARPA tracking.

• A. Automatic tracking lets the ARPA processor establish/update tracks; manual tracking requires the operator to select targets and input data to maintain tracks.
• B. Automatic tracking requires manual data; manual is fully automatic.
• C. Automatic tracking uses AIS data only; manual uses radar data only.
• D. Automatic tracking is slower than manual.

Answer: (A)

Automatic tracking is when the ARPA system automatically identifies targets, establishes tracks, and updates their positions and motion using radar measurements and automatic data association and filtering. The operator’s role in this mode is minimal for tracking; the system handles the target history, predicted positions, and updating the track as the target moves.

Manual tracking, on the other hand, requires the operator to select targets and input data to maintain their tracks. The navigator designates which radar returns to follow and enters or confirms measurements (bearing, range, course, speed) to keep the track alive. This mode is used when automatic tracking cannot reliably establish or maintain a track, such as in clutter or with ambiguous returns, giving the operator direct control over which targets are tracked.

So, the best description is that automatic tracking lets the ARPA establish and update tracks automatically, while manual tracking requires the operator to select targets and input data to maintain tracks.