Scale Factor Enhancement Method for Inertial Measurement in SERF Atomic Gyroscopes Based on Parametric Resonance and Envelope Detection

Although spin-exchange relaxation-free (SERF) atomic gyroscopes exhibit significant potential for high-sensitivity inertial measurements, further performance enhancements are constrained by inherent scale factor limitations. To overcome such limitations, a novel high-gain angular velocity sensing channel is proposed. Distinct from conventional parametric resonance (PR) techniques, the proposed channel is constructed specifically based on the absolute envelope under the PR state. Considering the nonlinear modulation characteristics under PR conditions, which manifest as waveform asymmetry, a local polynomial projection (LPP) algorithm incorporated with derivative consistency constraints is introduced to achieve high-precision absolute envelope reconstruction. Experimental results demonstrate that the RMSE of the envelope estimation is reduced by 64.44 % compared to traditional methods. By utilizing the extracted absolute upper envelope to leverage the PR-induced inertial amplification, the developed sensing channel breaks through conventional restrictions, enhancing the scale factor by a maximum of 39.40 %. Ultimately, under the absolute envelope-based framework, the inertial measurement sensitivity of the SERF atomic gyroscope is optimized from 7.45 × 10^-6°/s/Hz^1/2 to 3.49×10^-6°