In the Ring Laser Gyro Inertial Navigation System (RLG INS), the temperature characteristics of the accelerometer can directly influence the measurement results. In order to improve navigation accuracy in long-endurance marine navigation, the operating temperature of the accelerometer should be precisely controlled. Based on thermal studies on the accelerometer, temperature control precision should be better than 0.01 °C to achieve 1 × 10⁻⁵ m/s² output accuracy of the accelerometer. However, this conclusion is obtained by approximate calculations and cannot be directly applied to different inertial navigation systems. In order to verify this thermal conclusion and broaden its application, the Back Propagation Neural Network (BP-NN) algorithm is adopted to validate the feasibility of temperature control in this paper. In addition, a multi-level temperature control system is also set up and carefully designed to support the validation and experiments under different conditions. Test results of the temperature control system prove that operating temperature variation can be reduced to 0.01 °C. Meanwhile, the standard deviation per hundred seconds of the accelerometer outputs, after temperature control, reaches 1 × 10⁻⁵ m/s². Static altitude and navigation results were improved by 41.97% and 62.91%, respectively, with the precision temperature control system, which meets the long-endurance marine navigation requirements.

This paper presents a finite element simulated model to investigate parametric changes in the peak amplitude of a ring laser gyroscope. The finite element model is validated by comparing the theoretical amplitudes of two ring laser gyroscopes with simulated results, and the errors for the two gyroscopes are 1.3% and 1.6%. Based on this model, the parametric influences on the operation of the mechanical dither are obtained through simulation. The simulation results reflect the relationship between the geometric dimension and the peak amplitude of the mechanical dither. These findings are important for the optimal design and improved accuracy of a mechanical dithering ring laser gyroscope with bimorph piezoelectric actuators.

This paper presents an innovative interferometer based on the phase-generated-carrier method to meet the requirement of micro-vibration detection on an absolute gravimeter. Our results, including those of both simulation and experiments, verified the feasibility of the interferometer. Based on this interferometer, continuous micro-vibrations are obtained and synchronously compared with the results detected by a 991B seismometer. The interferometer’s accuracy reaches ${{10}^{ - 8}}\;{\rm m}$, and the detected vibration frequency is less than 100 Hz. These findings can help broaden the application of interferometers and provide new guidelines for vibration measurement.