Том 7, № 3 (2016)

The paper describes the sources of fundamental noises in FOG measurement signal. Methods of excess relative intensity noise (RIN) compensation are considered. Technique improving the compensation method using division of signals from two photodetectors for noise suppression is proposed and implemented. Functional simulation is conducted, which estimates the limiting theoretical value of noise suppression by the selected compensation method with the photodetector power of min 10 µW. Test results for FOG experimental prototype are presented. Allan variance plots for the cases with and without compensation are constructed.

Oscillation dynamics of a wave solid-state gyroscope with a resonator in the form of a thin elastic rotary shell mounted on a movable base is considered. A new mathematical model of the gyroscope, describing nonlinear interrelated electromagnetic and mechanical oscillations in the case that the coils of electromagnetic sensors carry voltage has been developed. Analytical estimation and numerical evaluation of the gyroscope errors have been performed.

Phase center offset (PCO) of GPS antenna has a considerable influence on the precision and accuracy of the resulting coordinates. As joint observation mode of various GPS receivers and antennas becomes increasingly universal, efficient determination of PCO values of multi-type dual-frequency GPS receiver antennas at the same time needs to be addressed urgently. According to the property of antenna PCO, a relative positioning calibration method, which is based on GPS relative positioning survey theory, is proposed. This method only needs two steps, each being a simultaneous observation of one consecutive sidereal day for the reference antenna and the calibrated antenna. Experimental results for several widely used GPS antennas show that this method greatly improves the calibration efficiency and can estimate horizontal PCOs for both frequencies. The proposed method can be fully applied to synchronously assess PCOs of multi-type dual-frequency GPS antennas in high precision position.

Proposals for improving the structure of the Russian geodetic reference network as a physical implementation of the terrestrial reference frame and one of the most important components of a unified system for positioning, navigation, and timing.

Application of modern global geopotential models to estimate the navigation informativity of the Earth’s anomalous gravity field (EAGF) is considered from the viewpoint of its use in autonomous (correlation- extreme) navigation. Various algorithms for calculating the characteristics of route and area navigation informativity, for which the authors use the variance and correlation radius of a measured EAGF parameter, are presented. The results of the experimental studies on estimation of the EAGF navigation informativity are discussed by analyzing vertical deflections and second derivatives of the perturbing potential in the Sea of Okhotsk with the use of the model EGM-2008 to degree 2190. It is shown that second derivatives of the geopotential demonstrate higher informativity as applied to navigation purposes.

The main objectives of this paper are to give an interdisciplinary overview of the current status of the research on planetary defense against asteroids, which is a real challenge, and consider technical proposals on the development of a multilevel planetary defense system based on modern space technologies, providing for the application of projectile asteroids to deflect target asteroids’ trajectories and distributed integrated navigation systems, the navigation equipment of which is supposed to be installed on many different objects. The composition of such navigation systems and their accuracies are discussed. This work is based on the results obtained by the international Research Laboratory of Space Research, Technologies, Systems and Processes [1], founded at Moscow Institute of Electronics and Mathematics (MIEM), Branch of Higher School of Economics (HSE) in 2011. The project was supported by the grant of the Government of the Russian Federation (2011–2013) [2, 3]. We have also used pioneering ideas from the course of lectures Models of planetary defense [4], prepared at the Department of Mechanics and Mathematical Modeling, MIEM NRU HSE in 2014 [4].