Patent ID: 8149417
Filing Date: 2012-04-03
Classification: G01C

Abstract:
1. A synchronous fiber optic gyroscope, comprising: a light source; an optical coupler in optical communication with the light source and configured to receive an optical signal from the light source; an optical modulator in optical communication with the optical coupler; a fiber optic coil in optical communication with the optical modulator; a detector configured to receive an optical signal from the optical coupler and convert the optical signal to an electrical signal; a loop closure signal processor having a first input, a second input and an output, the first input of the loop closure signal processor configured to receive the electrical signal from the detector; a phase lock loop having an input and an output, the output of the phase lock loop operatively connected to the second input of the loop closure signal processor; and a direct digital synthesizer operatively coupled to the input of the phase lock loop, the direct digital synthesizer configured to generate a low-frequency signal that is transmitted to the phase lock loop; wherein the phase lock loop converts the low-frequency signal to a high-frequency signal that is transmitted to the second input of the loop closure signal processor, and the phase lock loop provides signal modulation that is synchronous with signal demodulation.