Quantum Gyroscope Navigation — Sagnac Interferometer Dead Reckoning

Drive (GPS-denied tunnel)

Forward speed 2.0 m/s

Heading Sensor

MEMS bias drift 18 °/hr

Sagnac Ring — live fringe shift

Δφ (phase shift)0.000 rad

Navigation Readouts

True heading

0.0°

Estimated heading

0.0°

Heading error (drift)

0.0°

Position error (dead reckoning)

0.00 m

How it works

A robot with no GPS (a tunnel, a mine, a spacecraft, underwater) must estimate its own position by dead reckoning: integrating a known speed against a heading measured by an onboard gyroscope. The whole trajectory estimate is only as good as that one angle.

A Sagnac interferometer gyro splits a laser into two beams that travel the same fiber coil in opposite directions. Rotating the coil at rate Ω makes the clockwise beam's path effectively longer and the counter-clockwise beam's path shorter, producing a phase shift proportional to Ω:

Δφ = 8·π·N·A·Ω / (λ·c)

N = fiber turns (1000)   A = coil area (0.01 m²)
λ = laser wavelength (1550 nm)   c = speed of light

Because this reads Ω directly from light-path geometry rather than a mechanical/MEMS proof mass, a cold-atom or fiber-optic Sagnac gyro has bias instability thousands of times lower than a MEMS chip — its dead-reckoned heading barely drifts. A cheap MEMS gyro instead accumulates a slow random-walk bias (deg/hour), so its estimated heading — and the position integrated from it — silently diverges from the true path the longer the robot runs blind.

Turn Left / Turn Right — steer the rover; this is the real angular rate Ω the ring interferometer senses.
Quantum vs Classical — switch which gyro's estimate drives the dead-reckoned (dashed) trail.
MEMS bias drift — sets how fast the classical gyro's hidden bias random-walks, in °/hour.

Hold ◀ / ▶ or Arrow keys to steer

True path Dead-reckoned estimate Rover

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