The new generation ground control segment OCX based on new anti-jamming tech-nologies, forecasting algorithms and more frequent orbit and time data updates supporting gradual capacity building to control GPS Block III satellites with extra functions, for example, Navwar, will replace the existing operative control system OCS.

A very promising method for coping with the increasing demands on position accuracy for vehicular networks is cooperative positioning. Instead of adding more and more sensors in a self-contained system this technique aims exploiting information which already exists. This paper addresses a new cooperative GNSS positioning approach which is referred to as Advanced Shared Pseudorange (ASP) method. It customizes broadcasted GNSS pseudorange measurements of collaborating vehicles in a way that they can be applied in standard positioning algorithms. Specifically, in urban environments the increased number of usable satellites improves position accuracy or even makes GNSS position estimation possible in the first place. Moreover, the adjustment of pseudoranges from collaborating vehicles only requires inter-vehicle distance measurements as provided by radio ranging techniques. Thereby hardware costs are kept to a minimum. The capability of the new approach is emphasized by a comparison with other cooperative algorithms and test results of a loosely coupled GNSS/INS position estimation for a simulated urban road-segment scenario.

The paper focuses on vehicle attitude determination by a MEMS-based inertial measurement unit (IMU) comprising magnetometers and one-axis FOG, a multiantenna GNSS receiver, and a log integrated in an integrated orientation and navigation system (IONS) for sea-going ships.
IONS algorithms and errors in autonomous mode during long-term outages of GNSS signals are investigated.
Experimental prototype of GPS compass developed by Elektropribor has passed onboard tests in urban conditions, results from office studies of test data are presented.

The Hemispherical Resonator Gyro (HRG) has proven itself to be an ultra-reliable technology for space application with over 18 million operation hours and 100% mission success. Northrop Grumman Navigation Systems Division is developing a terrestrial inertial navigation system, INS, based on the proven space technology that can be used for precision pointing applications. The Precision Pointing Sys-tem (PPS) design yields a small size and lightweight system and will require only a few watts of power to operate. To achieve this small sized INS, the PPS utilizes a new golf-ball sized milli-HRG (mHRG) that is based on the current HRG 130P production gyro design used in extremely accurate space pointing systems. The power reduction is derived from a new electronics design based around low power elements.

The new mHRG gyro design has demonstrated bias stability performance better than the navigation grade gyros and will quickly attain this accuracy due to the extremely low noise characteristics of the HRG. Instrumental in the success of the mHRG performance has been the implementation of a calibration mechanization that eliminates the requirement for thermal control or modeling. This implementation will allow the INS to align quickly and will be advantageous for applications that have a quick response time requirement. Additionally, due to the stability of the mHRG the system can operate without GPS aiding for greater than an hour, while maintaining the attitude accuracy required for precision pointing, before an internal re-alignment is needed.

The simplified design of mHRG, has reduced the parts count by roughly 90% when compared to the current space qualified HRG production unit. With the major parts reduction it is projected that the mHRG can be produced efficiently and at a cost making it a viable choice for terrestrial applications.

The paper outlines the method for calibration of a strapdown inertial measurement unit (SIMU) based on fiber-optic gyros (FOG) in dynamic conditions on a test bed. Calculated components of linear velocity vector and position of SIMU accelerometer unit on the test bed platform are used as a reference.
The accuracy of a proposed method is estimated by testing the SIMU based on FOGs by IXSEA (France) on three-axis rate table by Acutronic.

The article is consecrated to the problem of the integration of an angular rate sensor (ARS) triad and a single-axis gyrostabilizer for a fast rotating SINS object. The integration is needed because of too high requirements for the accuracy of the scale factor of the ARS with sensitive axis on the axis of fast rotation. It is not possible to receive an acceptable result with a simple replacement of an AVS by a single-axis gyrostabilizer if its discretization error is too large to attain the needed accuracy. The solution of the integration problem is based on the possibility to refine the scale factor by the comparison of ARS measurements' time integral and frame rotation angle for the same time period. The specialty of the proposed solution is that the scale factor is being refined during all the flight time, the refinement accuracy is increasing with time and the accumulated object's orientation measurement error is corrected by a special algorithm. The article describes and founds the correctness of that algorithm.

The paper presents results of development and flight tests of БЧЭММ-1 micromechanical sensor unit - a component of integrated standby instruments system (ISIS) which is designed to sense aircraft roll, pitch and a heading angles in the event of the primary inertial navigation system or attitude and heading reference system failure. Design features, software algorithmic part, and calibration are considered. The Results of the unit flight tests within the TU-204SM aircraft ISIS are presented.

The paper summarizes the results of developing an approach to the use of informational redundancy in a widely met problem of attitude determination from two vector observations. This approach is based on using the relationship that should be met by all 12 vectors’ components. In the known publications this scalar relation was used for the sensor outputs checking only. Meanwhile it could be used for either (1) sensor errors calibration or (2) reconstruction of one component of one vector (in the case of incomplete composition of sensors or for the period when the in-put of one sensor is distorted, say, by a vehicle maneuver) as well.

In the paper the usefulness of such approach for the sensor calibration purposes is illustrated as applied to the gimbaled ESG-based INS. It is shown that with this additional relation in hand it became possible to determine all reasonable gyro drift model coefficients as well as the mechanical misalignments.

To demonstrate the advantages of using this approach for the reconstruction of one vector component the results of treating two attitude determination problems are presented. One refers to airplane attitude determination by means of accelerometers and magnetometers and the other to borehole attitude determination using gyro in-clinometer which has no sensor measuring the axial angular rate component.