If the GPS-INS difference is less than the threshold, what happens?

Master the Navigation, Seamanship, and Shiphandling (NSS) – Officer of the Deck (OOD) Phase 2 Exam with engaging flashcards and multiple choice questions, complete with hints and explanations. Prepare comprehensively for your test!

Multiple Choice

If the GPS-INS difference is less than the threshold, what happens?

When GPS and INS are integrated, a threshold checks how far apart their position estimates are. If the discrepancy is smaller than that threshold, the two sources are considered in agreement, so the GPS measurement is trusted and the INS update incorporates it. In practice, this means the GPS position is accepted by the INS and used to correct the INS solution, improving accuracy and reducing drift. The other possibilities would reflect a fault or disagreement—rejection, override, or shutdown—which don’t occur when the difference is within the acceptable range.

When GPS and INS are integrated, a threshold checks how far apart their position estimates are. If the discrepancy is smaller than that threshold, the two sources are considered in agreement, so the GPS measurement is trusted and the INS update incorporates it. In practice, this means the GPS position is accepted by the INS and used to correct the INS solution, improving accuracy and reducing drift. The other possibilities would reflect a fault or disagreement—rejection, override, or shutdown—which don’t occur when the difference is within the acceptable range.

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