I.V. Ryabov – Dr.Sc. (Eng.), Professor, Volga State University of Technology E-mail: ryabov22@mail.ru.

A.E. Makarov – Post-graduate Student,

Volga State University of Technology

E-mail: makarovAE@mail.ru

In urban conditions, positioning with the use of global navigation satellite systems is a complex task, since the diversity of natural and man-made objects can deteriorate signal propagation from the line of sight to the user.

The insufficient number of satellites or «bad geometry» occurs because of signal obstruction and limits the availability and accuracy of positioning solutions. 

In urban areas, the situation is exacerbated by the fact that existing signals can hardly reach the receiver of the user along the line of sight but they can occur because of oblique propagation (reflection and diffraction)of signals with the straight line of sight. These phenomena considerably deteriorate the obtainable accuracy of positioning in comparison with the operation in the open area.

A dual-system receiver of global navigation satellite systems(GPS +  GLONASS), as a rule, provides more observations of satellites than a single-system receiver and consequently a higher accuracy. Nevertheless, in urban areas, the registration ofnon-line-of-sight propagation is also very important. A characteristic example is the operation of the navigation receiver near the walls of the house, when the half of the sky is obscured. Therefore, the problem of improving the accuracy of positioning using algorithms of further processing of navigation messages is urgent. 

In the offered method there are areas with probabilities of position, therefore for the successful approximation to the navigation task solution, the introduction of weight coefficients is necessary. Their value is determined by the received signal power. The algorithm of the navigation task solution considers three components:

1. status of line-of-sight satellites 
2. the area of the map, determined byline-of sight satellites, 3) making a map with the most probable positions.

Synthetic tests showed that the algorithm allowed determining the position in conditions of urban overcrowding with time of cold start of 1 second with the maximum error of determining the position, equal to2 meters from the true position.

The article considers methods of improving the positioning accuracy of moving objects using signals of global navigation satellite systems. The schematic diagram of the receiver is offered. The algorithm of improving the positioning accuracy using signals of global navigation satellite systems, considering a 3D location map is suggested. The registration of satellite signals, resulting from multipathing and signals, passing through buildings, is presented. The method of operation of navigation equipment during considerable navigation signal attenuation is offered.

Ryabov I.V., Makarov A.E. Improvement of the positioning accuracy of moving objects using signals of global navigation satellite systems. Radiotekhnika. 2020. V. 84. № 9(17). P. 49−57. DOI: 10.18127/j00338486-202009(17)-04.

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