RU2484494C1 - Method of locating object - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: radio signals are received from several navigation space vehicles (NSV); the signals are processed; the optimum operating constellation of the NSV is selected; spatial coordinates of the object are calculated. Optical radiation of polar auroras is additionally used. Video monitoring of the polar auroras is simultaneously carried out and their region of propagation is determined. Radio signals from NSV whose paths pass through the region of polar auroras are blocked.

EFFECT: high accuracy of locating an object.

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Description

The invention relates to the field of radio navigation using radio waves and can be used in transport navigation to determine the location of objects at high latitudes and in the presence of auroras, as well as for the development of natural resources on the shelf of the northern seas.

The commissioning of the NAVSTAR (GPS) / GLONASS satellite radio navigation systems made it possible for a wide range of consumers to determine their position on the earth's surface, in the oceans and in near-Earth space with accuracy previously available only using sophisticated experimental technical means.

Currently, in real conditions, a further increase in the accuracy of determining the location of objects is affected by many factors that introduce errors that need to be eliminated.

Differential methods are known (Firsov Yu.G. Application of satellite radio navigation systems in hydrography. - St. Petersburg: Publishing House of the Moscow State Academy of Arts named after S.O. Makarov, 2004, p.35), compensating for errors. These differential methods are based on the relative constancy of a significant part of the errors in measuring pseudorange in space and time. Differential operation requires at least two sets of navigation equipment located at different points in space. Moreover, one set should be located at a point with known spatial coordinates (differential station), and the second at an acceptable distance (rover station). The differential station should be as accurately as possible tied to the spatial coordinate system. The differences of the measured pseudo-ranges to each set and the distances calculated from the known coordinates of the differential station are differential corrections.

The disadvantages of the known methods are the complication of the operation and operation of radio navigation systems due to the expansion of complexes of consumer hardware devices and a reduced range of action at a distance from differential stations from 30 to 200 km. Known methods in high latitude conditions, away from differential stations, cannot be used in GLONASS / GPS systems when determining location with increasing accuracy of positioning.

A known method of detecting ionospheric disturbances and determining the location of its source (US Pat. RF No. 2189051, publ. 10.09.2002). The method allows to identify the introduced errors in the operation of GLONASS / GPS that occur on signal propagation paths, which can be taken into account when using the GPS system to determine location at high latitudes. The method is based on the analysis of data obtained as a result of processing signals received by two-frequency receivers of the GLONASS / GPS radio navigation system located at the nodes of the array, with the number of receivers much more than 3 with additional complex mathematical data processing.

The disadvantages of this method are the complication of operation and operation, the use of an expanded number of hardware devices spaced to create lattice nodes, and the creation of an additional communication system between them. The known method in conditions of high latitudes due to insufficient saturation of the region with receiving devices of radio signals from navigation spacecraft (NSC), computers for signal processing and separation of navigation information to work in the measuring grid system cannot be used in GLONASS / GPS systems when determining location with increasing accuracy of its positioning.

There is a known method of excessive single-frequency measurements, including measurements over several (more than 8) spacecraft, averaging the spatial characteristics of the ionosphere, the selection of the optimal working constellation of the spacecraft (Yatsenov BC Basics of satellite navigation. GPS systems NAVSTAR and GLONASS. - M .: Hot line - Telecom, 2005, p. 104-107). The method partially takes into account non-predictable errors arising on the propagation paths at high latitudes during periods of auroras and related unpredictable ionospheric inhomogeneities. This method is closest to the proposed method and adopted as a prototype.

The disadvantage of this method is the averaging of the spatial characteristics of the ionosphere along the propagation paths from the working constellation over several navigation spacecraft (NSC), taking into account adverse paths that increase the error component.

The technical result, to which the claimed invention is directed, consists in increasing the accuracy of determining the location of objects located in high latitudes during periods of aurora.

To achieve the specified technical result in the method of determining the location of an object, including receiving radio signals from navigation spacecraft (NSC), processing them, choosing the optimal working constellation of the NSC, calculating the spatial coordinates of the object, they additionally use optical radiation from auroras and simultaneously monitor the auroras, determine their distribution area, block radio signals from the spacecraft with trajectories of radio paths passing through the polar region Wow shines.

Distinctive features of the proposed method for determining the location of an object from the above known, closest to it, are the following:

- additional use of optical radiation from auroras;

- simultaneous video surveillance of the auroras,

- determination of their area of distribution,

- blocking of radio signals from the spacecraft with trajectories of radio paths passing through the region of auroras.

Due to the presence of these signs, errors are reduced and the accuracy of determining the location of the object increases.

The specified technical result is achieved by the fact that according to the claimed method for determining the location of an object located in high latitudes, to improve the accuracy of determining its location, the effect of ionospheric inhomogeneities on the propagation paths associated with auroras is reduced. When applying the method, a space segment, a radio frequency path for receiving radio signals from navigation spacecraft (NSC) and a computer for processing signals and extracting navigation information are used, and the optimal operating constellation of the NSC is selected. In this case, optical radiation of auroras is additionally used and at the same time video surveillance is carried out for them, their distribution areas are determined. They block radio signals from navigation spacecraft (NSC) with trajectories of radio paths passing through the regions of auroras detected using optical video surveillance, and use only radio signals from navigation spacecraft (NSC) with trajectories of radio paths outside these areas.

The proposed method for determining the location of the object is illustrated by the drawings shown in figures 1-3.

Figure 1 presents a graph of the change in the H-component of the geomagnetic field intensity over time, the data are recorded at the Norwegian Björnoy station, figure 2 is a graph of the change in the accuracy of determining the location of the object in time at the station Murmansk, figure 3 is a keogram of the camera of the whole sky in Sodankylä (Norway).

The method is as follows.

To receive radio signals from navigation spacecraft (NSC), a radio frequency path is used in which radio signals are received and processed for the first time, and a computer for secondary processing of signals and separation of navigation information. The optimal working constellation of the spacecraft is selected and the spatial coordinates and the velocity vector of the object are calculated, followed by its geographical coordinates. At high latitudes, the ionospheric inhomogeneities of the propagation paths associated with the auroras make the main unpredictable errors, significantly reducing the accuracy of determining the geographic coordinates of the object. To exclude the influence of these ionospheric inhomogeneities associated with auroras, and to increase the accuracy of determining the location of an object, optical radiation from auroras is additionally used and video surveillance is carried out at the same time to determine the regions of auroras. Then, the optimal working constellation of the spacecraft is selected and the spatial coordinates of the object are calculated. At the same time, the radio signals from the satellite are blocked with the paths of the radio paths passing through the aurora region, thus reducing errors and increasing the accuracy of determining the location of the object. Experimental studies of changes in the accuracy of determining the location of an object using GPS during the development of auroral disturbances, some of the results of which are presented in figures 1-3, confirm the achievement of the technical result using the proposed method.

During the experiments, the navigation receiver worked in the full sky survey mode and received navigation information from a sufficiently large (excess) amount (usually from twelve) of the spacecraft, which guaranteed the ability to select the optimal working constellation of the spacecraft for processing. The radio signals of these satellites propagated through the ionosphere of the auroral zone and the polar cap, which is almost constantly disturbed. Figure 1 shows a graph of the change in the H component of the geomagnetic field intensity over time, the data were recorded at the Norwegian Björnoy station in the time interval from 18 h 01 min to 24 h 01 min March 25. Figure 2 presents a graph of the accuracy of determining the location of the object in the North-South direction using GPS in the time interval from 18 h 01 min to 24 h 01 min on March 25. Analysis of the data presented in figures 1, 2, shows that at some points the accuracy of determining the location of the object in the meridional direction decreased. In the period from 21:26 UT (universal time) to 22:54 UT (universal time) the navigation receiver ceased to function normally, which coincided with a sharp negative bay in the H component of the field at Bjornoya station. Figure 3 shows the keogram of the camera of the whole sky in Sodankyla, it displays the appearance of discrete forms that reflect the course of auroras. Analysis of all figures 1, 2, 3 shows that the maximum errors observed around 21 hours, as well as a complete disruption of the system from 22 hours 20 minutes to 22 hours 40 minutes coincided with the appearance of discrete forms of auroras. A comparative analysis of the materials obtained in the experiment suggests that the amplitude of the variations in the geomagnetic field is much less informative as a diagnostic sign of errors in determining the location of an object using GPS at high latitudes than spatio-temporal variations in the intensity of the forms of auroras.

To use the method of determining the location of an object at high latitudes, it is additionally necessary to use a surveillance camera that records auroras with a field of view of 180 degrees and a traditional means of processing and transmitting information over the regions of propagation of ionospheric inhomogeneities. During periods of aurora from a surveillance camera, information signals in the areas of their distribution are used to block radio signals from navigation spacecraft (NSC) with trajectories of radio paths passing through the region of auroras when choosing the optimal working constellation of the NSC and calculating spatial and geographical coordinates of increased accuracy.

Claims (2)

1. A method for determining the location of an object, including receiving radio signals from navigation spacecraft (NSC), processing them, choosing the optimal working constellation of the NSC, calculating the spatial coordinates of the object, characterized in that they additionally use optical radiation from auroras and simultaneously monitor the auroras, determine their distribution area, block radio signals from the spacecraft with trajectories of radio paths passing through the region of auroras. 2. The method according to claim 1, characterized in that it additionally use a surveillance camera with a field of view of 180 °.

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