Low noise underground environments offer conditions allowing to assess ultimate performance of high sensitivity sensors such as accelerometers, gyrometers, seismometers... Such facilities are for instance ideal for observing the tiny signals of interest for geophysical studies. Laboratoire Souterrain à Bas Bruit (LSBB) in which we have installed our cold atom gravimeter, provides such an environment. We report here the best short term sensitivity ever obtained without any ground vibration isolation system with such an instrument: 10-8 m.s-2 in 100 s measurement time.

The paper considers operation algorithms of a SINS based on angular rate sensors. Attitude gyro data are used in SINS algorithms to obtain the navigation solution. Calibration mode in the vehicle surface position uses GNSS data, and navigation mode in the vehicle submerged position uses water speed log data. Results from MATLAB (Simulink) simulation modeling confirm the effectiveness of applying attitude gyro data in SINS to significantly improve its informational autonomy.

Method of calibration SINS proposed. The method takes into account the complete errors equation for arbitrary rotations of the turntable. Application of Kalman filter in navigation mode allows you to obtain an estimate of SINS error calibration of accelerometers and gyroscopes. Accounting errors obtained allows calibration SINS in 3-4 iterative repetition. Source measurement Kalman filter are the speed of the navigation system. The method is not tied to a specific course turns the table, does not require analytical calculations and allows to obtain a quantitative estimate of the plan turns the table, and the error obtained calibration parameters.

In recent years there has been a growing interest in optical microresonators as viable low cost on chip micro-optical gyroscopes with navigation grade sensitivities. Here, we analyze and compare the rotational sensitivity of coupled resonator optical waveguide (CROW) gyroscopes to equivalent single resonator gyroscopes under various geometric constraints and device parameters. We show that the CROW gyros offer a sensitivity enhancement over conventional single resonator gyros at low propagation losses. However, the single ring resonator gyro is found to be more stable over a wider range of propagation losses as well as boasting greater sensitivities for larger propagation losses compared to a CROW of the same size. Furthermore, an analysis of the maximum achievable sensitivity for different material technologies (Hydex, silicon oxynitride, and SOI) is conducted. While all materials achieved tactical grade sensitivities, Hydex shows the greatest potential for CROW gyros because of the stability of its sensitivity over a wide range of device parameters.

Results of studies of the dynamics of micromechanical gyroscopes sensing elements in linear and angular vibrations of the base are given. Based on nonlinear differential equations of sensing elements motion the possibility of combination resonances development is determined. Experimentally discovered phenomena of excitation of sensing elements violent vibrations close to the frequencies of combination resonances are explained.

The features of dynamics and oscillation control of the ring resonator in a micromechanical gyroscope are considered. Inert properties of elastic vibrations are used in this gyro. The case when the resonator oscillations are excited according to the scheme of a self-excited oscillator with additional contour to stabilize amplitude of elastic vibrations is under study. In order to reach the required dynamic characteristics of the gyro, it is suggested that the feedback by the speed of the resonator ring radial travels in the zone, where readings are taken, be used in the measuring chan-nel. The procedure for getting a model of envelopes of physical oscillations in the form of differential equations is presented. This model is a convenient instrument to study characteristics of direct-measurement and compensatory type gyros.

The issues of development of micromechanical inertial sensors operating in the mode of self-oscillation are considered. The ways of the analysis of parameters of such sensors based on the analysis of information and energy characteristics, as well as the feasibility of micromechanical devices using the new element base: optoelectronic position sensors and magnetoelectric compensating converters. The advantages of such devices are described.

The paper describes reducing the sampling frequency of FOG output data. Aliasing effect is considered. Solution for reducing the FOG data output rate is proposed. Various methods for frequency reduction are considered. It is revealed that the currently used method is not an optimal one. A new method is proposed, based on the use of FIR filter chain. The methods are compared, and advantages of the novel method are clearly demonstrated.

A method for the gyroless missile control in the polar coordinate system is proposed; motion of material point under control force is studied; frequency characteristics of all the system components are calculated; correction filter is chosen; stability factors and a transfer constant of the control system are determined; mathematical simulation is carried out; the missile flight paths are obtained.