RU2482507C2 - Method of determining spatial coordinates of mobile object - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: method is based on determining coordinate errors of a mobile object through the imaginary location of a satellite relative the object. Coordinates of the object are adjusted by comparing the imaginary location of the satellite with its real position. That the error in determining coordinates of the imaginary position of the satellite will be the same for the imaginary position of the object is taken into account.

EFFECT: high accuracy of determining spatial coordinates of a mobile object by taking into account errors caused by refraction of signals when passing through different layers of the atmosphere.

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Description

The invention relates to the field of radio navigation, and in particular to determining the location of a moving object.

A known method for determining the spatial angular orientation of a moving object from the description of the patent of the Russian Federation 2112926 IPC G01C 19/06, published on 10.06.1998. The method is intended for use in inertial navigation systems. The method includes periodically reversible rotation of the platform about an axis rigidly connected with the object. The projections of the absolute angular velocity and the angle of rotation of the platform relative to the object are measured. The current values of the spatial angular orientation of the moving object are calculated.

There is also a method of determining the coordinates of moving objects from the work of Vasilyev Yu. And Kamyshov A. "A system for determining the coordinates of moving objects with laser tracking." Components and Technologies Magazine, No. 9, 2005. The coordinates of moving objects are recorded by a heat direction finder. The accuracy of the registration of coordinates depends on the accuracy of the tracking system of the direction finder and pointing the laser signal to a moving object.

A known method for determining the coordinates of a moving object in three-dimensional space (RF patent 2267797 C2, IPC G01S 3/14, published January 10, 2006. "Method for determining the coordinates of an aircraft (LA) and a device based on it"). By the maximum number of similar essential features, this method is taken as a prototype.

The known method consists in forming a radio navigation system with a computer complex of two ground-based radiation sources in azimuth and elevation. In this case, the signals of the radiation sources are modulated in time by a set of frequencies, each of which corresponds to a certain value of the angle of rotation of the antenna. On board the aircraft, azimuth and elevation signals are received and the angular coordinates of the aircraft are determined from the modulation frequency of the received signal. The signals are generated in the form of a set of pulses corresponding to the encoded range value, and the range code is decoded on board the aircraft. The method provides increased flight safety and can be used with high accuracy in the near navigation zone, as well as during takeoff and landing. However, the propagation speed of the electromagnetic signals of the radio navigation system depends on the propagation medium, which is heterogeneous, especially with increasing flight altitude (stratosphere, troposphere). In these cases, refraction of the signals is observed, which introduces errors in the measurement of coordinates.

The problem, the solution of which is carried out by the claimed method, is to increase the accuracy of determining the spatial coordinates of a moving object using the computing complex of the radio navigation system of spatial coordinates of a moving object by taking into account the errors caused by the refraction of the electromagnetic signals of the satellite radio navigation system during the passage of inhomogeneous layers of the atmosphere.

The essence of the proposed method as a technical solution is expressed by the following set of essential features.

As in the prototype, in the claimed method, the signals are emitted by the radio navigation system, are received and processed with the subsequent determination of the coordinates of the moving object in a three-dimensional coordinate system.

In contrast to the prototype, the coordinate errors caused by the refraction of the electromagnetic signals of the satellite’s radionavigation system during their passage in different layers of the atmosphere are taken into account. Errors are determined through the imaginary location of the satellite. The coordinates of the imaginary position of the satellite are determined. Compare it with the actual position of the satellite. The errors of these coordinates are calculated. Moreover, the errors in determining the imaginary coordinates of the satellite are the same as for the object. Therefore, the coordinates of the position of the moving object are adjusted taking into account the same errors.

The technical result that can be obtained by implementing the proposed method is to increase the accuracy of determining the spatial coordinates of the object by taking into account the errors caused by refraction.

The essence of the proposed method is illustrated by the drawing, where figure 1 shows a diagram for determining the spatial coordinates of a moving object receiving signals from a radio navigation system of the satellite.

- Wed - the actual position of the satellite with the coordinates X Y Z.

- See - the imaginary position of the satellite with coordinates x y z.

- The dotted line indicates the path of the signal through the atmosphere and through the ion layer.

- Bp - the actual position of the object with the coordinates X _in , Y _in , Z _in .

- Vm - the imaginary position of the object with coordinates x _in y _in z _in .

- α is the angle between the horizontal vector and the direction to the satellite.

The inventive method for determining the spatial coordinates of a moving object is as follows (figure 1). The signals propagate from the radio navigation system of a real satellite C, the coordinates of which are known C (X Y Z). Passing through the atmosphere, the signals are distorted. The distortion is due to a decrease in the refractive index n of the atmosphere with an increase in height n = c / v, where

C is the speed of propagation of signals in a vacuum,

ν is the propagation speed of signals in the medium with a coefficient n. For signals from the radionavigation system of a satellite and a moving object, the greatest influence on this speed is exerted by the layers of the ionosphere and troposphere, in which the velocity has a deceleration effect. The ionosphere refractive index n <1. When passing through the ionosphere layer, the signal path from the radio navigation system of satellite C to object B is different from a straight line. All solutions of equations 1, 2, 3, 4, 5 are provided by the computing complex of the radio navigation system. The coordinates of the imaginary position of the object BM (x _in y _in z _in ) are determined. The position of the imaginary satellite Cm is determined, and the real position of the satellite Cp is known. The imaginary position of the moving object is Vm (x _in y _in z _in ). The actual position of the moving object is Bp (X _in Y _in Z _in ). The coordinates of the imaginary position of the satellite Cm (x y z) are calculated by the formulas

where D is the imaginary distance to the object Bp.

The angle α gives the line of sight not to the actual position of the satellite Cp, but to its imaginary position at a distance D from the object Bm (x _in y _in z _in ).

The equation of a line passing through the imaginary location of the satellite Cm in the direction α,

The equation

connects the dependence of the coordinates of the real position of the satellite Cp and imaginary Cm, where r is the error in determining the real position of the satellite, taken modulo.

The solution of the system of equations 1, 2 and 3 gives the imaginary coordinates of the satellite Cm (x y z).

Thus, having obtained the imaginary coordinates of the satellite and knowing the real coordinates, we can determine the errors

Errors in determining the imaginary position of the satellite See are the same as for the Vm object.

Then the real coordinates of the object Bp (X _in Y _in Z _in ) are as follows:

The resulting mathematical model makes it possible to reduce coordinate errors caused by refraction of signals in the atmosphere, depending on flight conditions, the state of the atmosphere, time of year, day, and the like.

The errors Δx, Δy, Δz are determined, since the errors in determining the coordinates of the imaginary position of the satellite Cm are the same as for the object Bp. Using the computing complex of the radio navigation system, the coordinates of the imaginary position of the moving object Vm are corrected taking into account the errors Δx, Δy, Δz and the spatial position of the moving object Bp is determined.

Achievable technical result of the proposed method is provided by taking into account errors in determining the spatial coordinates of a moving object. The method for determining the coordinates has increased accuracy due to the inclusion of errors caused by refraction of signals in the atmosphere, since the current state of the atmosphere is constantly monitored, and not its statistical models. The atmospheric state model around the airport, the tropospheric and ionospheric models do not provide the required accuracy. For unmanned moving objects based on obtaining information about the spatial position using the proposed method, it is possible to solve the problem of stabilizing the flight path without expensive inertial equipment.

A method for determining the spatial coordinates of a moving object is implemented by the radio navigation system of the satellite and the moving object with a computer complex.

Bibliography

1) RF patent 2267797 C2, IPC G011 S3 / 14, G01C 23/00. Published January 10, 2006. “A method for determining the coordinates of an aircraft and a device based on it”;

2) Vasiliev Yu., Kamyshov A., “The system for determining the coordinates of moving objects”. Components and Technologies Magazine, No. 9, 2006;

3) RF patent 2112926 C1, IPC G01C 19/66. Published on June 10th, 1998. "A method for determining the spatial angular orientation of a moving object";

4) Shebshaevich B.C. et al. “Network satellite radio navigation systems”, M .: Radio and communications, 1993

Claims (1)

A method for determining the spatial coordinates of a moving object, which includes emitting signals from a satellite radio navigation system with a computer system, receiving and processing them on an object, followed by determining the spatial coordinates of a moving object, characterized in that it additionally takes into account spatial coordinate errors caused by refraction of signals emitted by a known radio navigation a real satellite system with known coordinates, for which, using a computing set The radio navigation system of a real satellite determines the coordinates of the imaginary position of the satellite, compares it with the known coordinates of the real position of the satellite, determines the errors of these coordinates, and then the coordinates of the moving object are adjusted taking into account the errors of the coordinates of the satellite’s position, given that the errors of the coordinates of the satellite’s position are the same as for moving object.

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