Spectral switch anomalies in a Sagnac interferometer with respect to a Galilean frame.

We report the spectral switch shift around spectral anomalies in a gyroscopic Sagnac interferometer, which is normally used to calibrate the angular momentum of a gyroscope. The spectral shift in the rotating gyroscope is explained with respect to the longitudinal Doppler shift of the counterpropagating beams in the Sagnac interferometer.