The paper traces the outstanding role of the Russian Academy of Sciences in the formation and development of science in the country by the example of navigation.

The paper considers interrelation, distinctions and features of Kalman and Wiener algorithms for processing the results of marine scalar gravimetric survey. Their advantages and disadvantages in solving the filtering and smoothing problems are analyzed. The authors present and compare the results obtained with the use of various recursive filters in simulation and real data processing. The filters consistency and the need to identify the models of signals and noise are discussed

The paper describes an algorithm of in-flight roll angle estimation for a spinning vehicle fol-lowing an unguided trajectory based on MEMS gyroscope triad data. The roll angles are esti-mated with a phase detector by demodulating the signals of transverse gyroscopes with sub-sequent least squares processing.

The star tracker error model is presented as a decomposition into fluctuation and systematic errors. The fluctuation error arises when calculating the coordinates of the brightness center of the digital star image and is due to the discrete structure of the signal in the image sensor. If the observation of stars is performed through the atmosphere, the fluctuation error has an additional external component associated with the “trembling” of star images due to atmospheric turbulence. The systematic error arises due to errors in the calibration of intrinsic elements of a digital camera. For all components of the attitude error, linearized analytical expressions and covariance matrices are obtained, depending on the configuration of the observed constellation. The error model can be easily rewritten in the form of the camera intrinsics calibration errors observation equation in a tightlycoupled astronavigation system. The results of experimental verification of the developed error model are presented. The numerical values of the errors obtained in the experiment clearly show the need for regular calibrations of the intrinsic elements of the star tracker’s digital camera during operation. 

The paper considers an algorithm used to detect a dipole signal against the noise background under arbitrary motion of the magnetometer platform. The constructed mathematical model of the dipole signal in the form of a series of six basis functions allows both detection and estimation of the source position with one contact. The hardware-inthe-loop simulation results have been presented. 

The article presents the results from the experimental study of a modified artificial neural network MFNN (minimum fuel neural network). Sparse representation of complex data with overcomplete basis and L0/L1 norm optimization is used instead of the classical fast Fourier transform (FFT) algorithm. The results showed a significant enhancement in the abilities of obstacle recognition and autonomous railway control systems to distinguish between close objects, such as trains on adjacent tracks of marshalling yards.

This paper proposes a clock bias gross error detection method, which combines weight- ed support vector data description (SVDD) with modified median absolute deviation (MAD) to address the limitations of the traditional MAD method. The method uses the local reachable density as the weighting factor of SVDD, which fully considers the local characteristics of each data. By constructing the minimum hypersphere in the high-dimen- sional feature space, the one-dimensional data are transformed into the distance from the vector point to the center of the hypersphere in the high-dimensional space. This trans- formation increases the discrepancy between normal data and gross errors. The modified MAD method probes the distance from the current epoch vector point to the center of the hypersphere for gross errors, and thus determines whether the current clock bias is a gross error. The precision clock bias data of BDS-3 with different sampling intervals provided by GFZ were used for simulation experiments. By comparing the results of the MAD method and the WS-MAD method, it is found that the WS-MAD method can detect the small gross errors in the smooth clock bias frequency data and more gross errors in the clock bias data with trend term floating. The fitting and prediction analyses on satellites with different orbits and clock types show that the WS-MAD method improves the fitting and prediction accuracy of MEO and IGSO satellites better than that of GEO satellites. For the same MEO satellites, the enhancement effect of hydrogen clocks is better than that of rubidium clocks.

The article focuses on the problems of GPS application and offers an overview of different GPS backup technologies and approaches proposed in the USA, the European Union, the UK, China and some other countries to overcome its shortcomings. Also considered are some well-known PNT services using LEO satellite signals, e-Loran radio navigation system, as well as some exotic approaches.

The paper presents a brief history of development of modern scientific periodicals covering the theoretical issues, design and application of marine navigation equipment, and the analysis of these publications. The authors describe top five global journals specializing in this scientific discipline. The subjects of their publications are discussed, and the ratings according to the Scopus database are presented. Based on the keywords, ten periodicals publishing the largest number of articles on the navigation equipment engineering in Russia are identified in the Russian science citation index. Some specific features of these journals are considered, and the ways of their further development are proposed.