- #1

KDP

- 24

- 7

- TL;DR Summary
- A simulation seems to show that a Sagnac gyroscope can be affected by purely linear constant proper acceleration. Is this correct?

As some of you know I have been coding a 2+1D relativistic simulator that can handle (constant proper) acceleration in any direction on a plane. So far it is going quite well.

I have now decided to simulate a Sagnac gyroscope inside the simulation by sending signals in opposite directions around the square object and comparing the difference in return times of the signals. To my surprise it seems that a Sagnac gyroscope can be affected by purely linear acceleration unless the emitter and the centre of the Sagnac loop both lie on a line that is parallel to the linear acceleration. This is not ideal if the gyroscope is intended to measure rotation only, as it requires knowing or measuring the linear acceleration in order to calculate the rotation from the difference in the return times of the counter rotating signals.

This would require having to use a separate device that only measures linear acceleration in conjunction with a Sagnac gyroscope, so that the rotation can be calculated. Alternatively two Sagnac gyroscopes that are aligned with their emitters orthogonal to each other can be used, as the linear acceleration can be calculated by comparing the time differences on the two orthogonal gyroscopes. Is my conclusion correct or do I need to continue looking for bugs in my coding?

P.S. Would I be correct in thinking an ideal traditional flywheel gyroscope is not affected by linear acceleration?

I have now decided to simulate a Sagnac gyroscope inside the simulation by sending signals in opposite directions around the square object and comparing the difference in return times of the signals. To my surprise it seems that a Sagnac gyroscope can be affected by purely linear acceleration unless the emitter and the centre of the Sagnac loop both lie on a line that is parallel to the linear acceleration. This is not ideal if the gyroscope is intended to measure rotation only, as it requires knowing or measuring the linear acceleration in order to calculate the rotation from the difference in the return times of the counter rotating signals.

This would require having to use a separate device that only measures linear acceleration in conjunction with a Sagnac gyroscope, so that the rotation can be calculated. Alternatively two Sagnac gyroscopes that are aligned with their emitters orthogonal to each other can be used, as the linear acceleration can be calculated by comparing the time differences on the two orthogonal gyroscopes. Is my conclusion correct or do I need to continue looking for bugs in my coding?

P.S. Would I be correct in thinking an ideal traditional flywheel gyroscope is not affected by linear acceleration?

Last edited: