Three-axial fiber optic gyroscope

We consider a new design of a high-precision three-axial sensor of angular velocities whose sensitive elements are fiber optic gyroscopes using the Sagnac effect. The instrument is designed for measuring the rotation velocity of an orbiting spacecraft (microsatellite) and for performing its attitude control.     

An alternative algorithm for the spacecraft information system with magnetometer and solar sensor

The possibility of identification of motion parameters of a low-orbit spacecraft using readings of a three-axis magnetometer and solar position sensor, without integration of the Euler’s dynamic equations or direct measurement of the object’s angular velocity, is considered.     

雷达低空测向环境中的直达波DOA估计算法

基于低空测角模型,提出了一种基于四阶累积量的直达波方位估计算法。该算法首先采用Pro—VESPA算法估计出广义方向矩阵,再利用目标直达波信号和多径信号之间的仰角几何关系,不需已知多径信号的相干系数,对广义方向矩阵函数一维搜索就可直接精确获得直达波方位,算法适用于高斯白噪声或色噪声环境,具有较好的鲁棒性。计算机仿真验证了该算法的有效性。     

Ionospheric disturbances in the north-east region of Russia according to ionosonde data in the periods of equinoxes

Ionospheric disturbances in the equinox periods of 2005–2006 are considered on the basis of the ionosondes of vertical and oblique sounding located in the north-east region of Russia. It is found that the X-ray flares observed in the first half of September 2005 caused an additional increase in the ionization of the lower ionosphere in the daytime, this fact leading to a development of absorption and an increase in the lowest observable frequencies at the Magadan-Irkutsk and Noril’sk-Irkutsk radio paths. Wave-like changes in the maximum observable frequencies and critical frequencies with periods of about 2–2.5 h were detected during the magnetic disturbances. Oscillations of the planetary wave type with periods of 4–5 days were also revealed.     

Planar inertial motion of an elastic cluster of three bodies

A problem of planar inertial motion of three bodies connected in the form of a triangle by an elastic imponderable filament is considered, as well as a particular case of the problem of motion of a closed chain of n bodies. This configuration can be a basis for extended planar constructions in deep space.The bodies are considered as material points. The paper elaborates a subject of [1]     

Vertical structure of the magnetic field in active regions of the sun at coronal heights

High-altitude measurements and magnetic field distribution in active regions are always an important problem to verify existing models at heights from units to hundreds of Mm. Optical methods of analysis of the magnetic structure work well only at the photosphere level. At the same time, the progress of radio astronomy methods of analyzing the solar radio emission [1] and of the theory of solar plasma radiation [2] facilitates introduction of new methods for measuring the magnetic field strength at various altitudes in the solar atmosphere. In this paper we use multi-wave observations of polarization of the radio emission of active regions in the microwave range together with precise magnetosphere data in order to develop a method of projection for measuring the height distribution of the magnetic field.     

Determination of two Satellites’ relative motion using tracking measurements

A technique to determine the initial relative velocity of two satellites at the initial time instant, based on the results of NORAD system’s measurements, is presented. The determination of a relative initial position is shown to result in the unsatisfactory accuracy. This technique is applied to determining the initial velocity of separation of the first Russian nanosatellite TNS-0 from the International Space Station.     

Multi-structural estimation of an integrated navigation system of a reusable spacecraft

An approach to the synthesis of an integrated navigation system is considered for a reusable space-craft that performs an arbitrary spatial maneuver under the conditions of internal and external disturbances. The offered approach provides for a noise-suppressing solution of the navigation problem, both in a regular mode of spacecraft motion, and during its descent along the unplanned trajectory.