NotesQuestions
0/10 correct
INSTRUMENTATION — CH.19

Inertial Reference SystemNavigation — Instrumentation — DGCA CPL practice questions

Question 1 of 1

Dither is used in a laser gyro in order to:

A.Enhance the accuracy of the gyro at all rotational rates
B.Increase the maximum rotational rate that can be sensed by the gyro
C.Stabilize the laser frequencies at peak power output
D.Break the frequency lock which would prevent small rotational rates from being sensed by the gyro

All 1 question — Inertial Reference System

Navigation — Instrumentation · DGCA CPL. The correct option is marked on each.

  1. Q1. Dither is used in a laser gyro in order to:

    • A.Enhance the accuracy of the gyro at all rotational rates
    • B.Increase the maximum rotational rate that can be sensed by the gyro
    • C.Stabilize the laser frequencies at peak power output
    • D.Break the frequency lock which would prevent small rotational rates from being sensed by the gyro✓

    Why: At very low rotation rates, back-scattering between the two counter-rotating laser beams causes them to "lock" together (synchronise), dropping the output frequency to zero — so the gyro cannot sense those very small rotations. The piezo-electric dither motor vibrates the laser ring about its input axis, taking the gyro through the lock-in region and preventing synchronisation. The dither motion is then electronically decoupled from the output so it does not introduce navigation error. This is the single most-examined point from Chapter 19. Remember: Dither = breaks lock-in = allows sensing…