RU2503969C1 - Triangulation-hyperbolic method to determine coordinates of radio air objects in space - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: triangulation-hyperbolic method to determine coordinates of radio air objects (RAO) in space relates to the field of passive location and may be used to solve tasks of RAO coordinates determination and trajectories of their movement in space using the base-correlation method. The method consists in measurement at all receiving stations: on one central and several peripheral stations, angular coordinates of RAO and differences of distance between the central and peripheral receiving stations. Coordinates are determined within two stages: at the first stage they determine a strobe of RAO location, received on the basis of angular coordinates of this source, measured by central and all peripheral receiving stations (triangulation method). At the second stage in the received strobe they calculate differences of distances between central and all peripheral receiving stations, they determine the accurate place of RAO location in space. At each peripheral receiving station for measurement of the difference of time of signal delay by a command from the central station they set a bearing for RAO to meet a condition of reception of one and the same signal by all receiving stations (using a hyperbolic method).

EFFECT: higher throughput capacity of a multi-position system of passive location.

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Description

The invention relates to the field of passive location and can be used to solve the problem of determining the coordinates of radio-emitting air objects (RVO) and the trajectories of their movement in space when using the basic correlation method, as well as in scientific research.

To determine the location of radio-emitting air objects in space by means of a passive location, the triangulation method, the hyperbolic method and their combinations implemented in multi-position systems are used / Theoretical basis of radar. Ed. Professor Y.D. Shirman. M .: Sov. Radio, 1970, pp. 494 ... 497 /.

The triangulation (goniometer) method is little dependent on the types and size of the frequency spectrum of the received radio signals. The main advantage of this method is the high energy of its receiving channels, since two or more high-potential radio direction finders (RTP) with sufficiently large gain (more than 20 dB) antennas are used to measure the angular coordinates of the PBO, which together with the adaptive receiving device provide high real sensitivity. This makes it possible to detect and direction-finding almost all over-horizontal PBOs at large (hundreds of kilometers) ranges by their background radiation.

From the studied sources of information the following technical solutions are known.

/ For example, RF patent No. 2275649, IPC G01S 3/02, G01S 3/46, 2006 /, "Method for determining the location of radio emission sources" / RF Patent No. 2259541 IPC 7 G01S 5/04, 2004 /, "Method for determining the coordinates of a moving source of radio emissions with unknown parameters and a device for its implementation ”/ RF Patent No. 2234712, IPC 7 G01S 11/00, 2004 /,“ Triangulation Method for Determining the Positions of Archaeological Objects ”/ German Patent No.DE 102005030557 A1, 2007, Korean Patent No. KR 10 -2010-0126979. 2010,

The above sources mainly differ from each other by the methods used for measuring angular information about the target, both in terms of classical (e.g. least squares, maximum likelihood, etc.) and non-classical (non-statistical, invariant-group, optimization, etc.). d.).

The hyperbolic (differential-ranging) method of determining the location of the target is used in a multi-position system consisting, in the general case, of 3 or more receiving points (PP) located on the ground. In this case, one of the reception points serves as the central reception point (CPP).

The specificity of this method is such that, in contrast to the triangulation method, this method requires the fulfillment of the “cooperative reception” condition, i.e. reception of the same signal emitted by the source of radio emission by all PP. To fulfill this condition, the PCs are equipped, as a rule, with wide-angle antennas and having, as a result, a low gain (not more than 5.0 ... 7.0 dB). The resulting total energy potential is quite sufficient for determining, by the chronometric method, sufficiently accurate differences in the received signals of radiation sources such as short range radio navigation interrogators, identification transponders, etc., using simple short-pulse signals with steep fronts and operating at fixed frequencies in the 30-cm wavelength range and, just as importantly, their radiation sources have a circular radiation pattern. At the same time, the tracking range of such VVOs can reach 300 ... 400 km.

At the same time, most airborne electronic equipment (RES) of airborne objects mainly use complex phase-modulated, frequency-modulated, pseudorandom sequences, etc., which are, as a rule, long-pulse signals with indefinitely pronounced fronts / Issues of prospective radar. Collective monograph. Ed. A.V. Sokolova. - M.: Radio Engineering, 2003 /. To accurately measure the differences in the course of such complex signals between the received PP and the DSP, it is necessary to use the basic correlation method / Theoretical basis of radar. Ed. Professor Y.D. Shirman. M .: Sov. Radio, 1970, pp. 498 ... 511 /.

The use of the basic correlation method involves a special switchable (tunable) device in the device for measuring the differences in the signal path, which compensates for the difference in the delay of the signals with a delay range from O to the private one obtained by dividing the two basic distances between the PC and the CPT by the speed of propagation of an electromagnetic wave in free space .

Among the known sources in which the hyperbolic method is used to determine the location of the IRI, the following can be attributed: “Method for determining the location and identification of moving objects and a system for its implementation” / RF Patent No. 20133785, IPC 5 G01S 13/00, 1994 /, “ Difference-range-finding method for direction finding of radio emission sources and its device ”/ Patent No. 2258242, IPC 7 G01S 3/46, 11/02, 2003 /,“ Difference-range-finding method for determining the coordinates of a source of radio emission and its device ”.

It is known, for example, the technical solution for determining the sources of radio emission according to the patent of the Russian Federation No. 20133785 IPC 5 G01S 13/00, 1994, "Difference-range measuring method for direction finding of sources of radio emission and its device".

In RF patent No. 201385 IPC 5 G01S 13/00, 1994, the difference-ranging method for determining the location of the IRI based on the discrete conversion of two signals and further calculation of their cross-correlation function in the frequency domain is described quite deeply. This fact predetermines the universality of the use of the mathematical apparatus proposed in the method for calculating the path difference of both simple and complex modulated signals.

As a significant drawback of difference-ranging systems that use the base-correlation method when calculating the difference in the signal path, this occurs independently in the time or frequency domains, because the system’s low bandwidth is due to the need to conduct from several thousand to several tens of thousands of maximum search operations -correlation function for each pair of signals (direct and delayed) for delay compensation with a certain step (delay compensation step), fissioning resolution signal path difference measurement (measurement accuracy of the difference signal travel).

As a well-known combination of the combined use of the goniometric (triangulation) and difference-rangefinder (hyperbolic) methods, the so-called goniometric-difference-rangefinder or goniometric-hyperbolic method is considered.

The closest in technical essence of the claimed subject matter of the invention is the solution according to the patent of the Russian Federation No. 2275649 IPC 7 G01S 3/02 3/46. publ. 2005 / "A method for determining the sources of radio emission and a passive radar station used in the implementation of this method."

From the patent of the Russian Federation No. 2275649 there is a known method of determining the IRI with the combined use of triangulation and difference-ranging methods. The essence of the method is the detection and direction finding of IRI using at least two passive radar stations (RLS) spaced in space from the central (reference) RLS and calculating the coordinates of these sources of radio emission in three stages. At the first stage, at each RRL, search and detection of IRI is carried out, the time-frequency parameters of their signals are measured, at the second stage, at least two RRLs continuously monitor the selected IRI and record the reception time of each pulse of this IRI, at the third stage, by measured bearings and times reception of each pulse followed by IRI ultimately determine its azimuth and location coordinates on the Earth's surface.

It should be noted that, after solving the problem of determining the coordinates of the RVO with a given accuracy, the second key problem of multi-position passive location tools using the correlation method for determining the delay time is the ability of these tools to quickly solve this problem, i.e. to have a given throughput, especially, which is relevant for the work on the emissions of highly dynamic airborne RES radio facilities.

A disadvantage of the known technical solutions is the low throughput comparable with the hyperbolic method using the correlation method for determining the difference in the signal path (RF Patents No. 20133785, 2258242, 2275649) and the complexity of the method (The required number of spectral components is RF patent No. 20133785, three stages for computing the coordinates of the PBO - RF patent No. 2275649).

The objective of the invention is to increase the throughput of a multi-position passive location system using a goniometric-hyperbolic method for determining the location of the PBO to a level comparable to a multi-position passive location system using a triangulation method.

The problem is solved due to the fact that in the known method for determining the coordinates of airborne objects from the radiation of their on-board electronic equipment (BRES), including the detection of radiation, the measurement of bearings of radio emission sources and the difference in the signal path using at least two peripheral radio direction finders that play the role of PP, spaced in space from the central direction finder, which plays the role of the CPP, and the subsequent calculation of the coordinates of the sources of radio emission in a goniometric-hyperbolic way, the location of the PBO is carried out in two stages, at the first stage, at each PCB, in the direction and frequency range agreed with the CPP, the PBO is searched and detected by the radiation of their BRES, the time-frequency parameters of the emitted signals and bearings of their sources are measured, the signals are identified among themselves, the detected PBOs are identified, the coordinates of their location are calculated in a triangulation manner, the accuracy of which is characterized by the so-called position gates in space, with their components measures in Cartesian or polar coordinates in the form of their standard errors, respectively, - σx, σy, σz or σR - range, αβ - azimuth, σε - elevation angle, then, in the second stage, using the hyperbolic method with the number of PP more than three in the received strobe specifies the coordinates of the radio-emitting air object (see figure 1).

However, with the number of RTP in the complex of less than four PP (except for the CPP) to obtain a unique solution, the problem arises of converting the superior number of target coordinates to the number corresponding to the number of linear equations obtained (see figure 2). It should be borne in mind that with the composition of the passive location complex (CPL) of 3 RTPs, the circular view of the space becomes ineffective. Work with acceptable accuracy can only be carried out in sectors of 60 ... 80 degrees, when placing their peaks at the location of the CPP and located on both sides of the CPL, which in this case is a straight line with the CPP in its center and spaced on both sides of it the value of the measuring bases of peripheral software (see figure 3).

Obtaining a unique solution using the values of azimuth (β ₀ ) and elevation angle (ε ₀ ) of the target, which are generalized from all RPTs and reduced to CPP and obtained from solving the triangulation problem. The use of the azimuth and elevation angle of the target to solve the problem of determining the location of the RVO is carried out taking into account the restrictions on the length of time "aging" of these indicators. It is proposed to determine the time interval for using the current azimuth value and the elevation angle of the target obtained in the triangulation method, in the subsequent, second stage, during the operation of the hyperbolic method, until they, during their “aging”, exceed the limits of ± (σ ... 3σ), in depending on the nature of the problem to be solved, where σ is the standard error of the determination of the bearing of the CPP-RVO (see Fig. 4).

A comparative analysis of the claimed solution with the closest analogue shows that the proposed method differs from the known one by the presence of new conditions and the order of their implementation: obtaining the strobe of the spatial position of the VVO as a result of triangulation measurements and clarifying the position of this object in it through the use of a triangulation-differential-ranging method (with the composition of the RTP in the KPL from five or more) and - difference-range measuring method (with the composition of the RTP in the KPL of less than five). In this regard, the proposed method meets the criteria of the invention of "novelty."

The essence of the invention is to determine at the first stage the error region for determining the coordinates of a radio emission source in a triangulation (goniometer) method, hereinafter referred to as the coordinate gate of the radio emission source, and then, at the second stage, using the difference-range-measuring (hyperbolic) method, the coordinates of the source are specified in the resulting strobe radio emissions, including with a limited number of PP (less than 4) in the KPL, taking into account the “old” azimuth and elevation obtained at the first stage of triangulation a manner.

In the proposed method, the airborne radar of airborne objects, most of which use complex modulated signals (LFM, FCM and the like), are considered as emitting objects. In contrast to simple pulsed short signals, the measurement of the delay time of such signals, as a rule, is carried out on the basis of determining the cross-correlation function (CCF), i.e. correlation method. In devices that produce VKF, a mandatory element is the presence of a tunable delay line with a range of signal delays from 0 to the quotient from dividing the two values of the measuring bases by the speed of propagation of the electromagnetic wave in free space. Therefore, one of the key problems of multi-position passive location tools that use cross-correlation functions to determine the delay time is the ability to "quickly" determine the desired delay of the compared signals, a quantitative indicator of which is the maximum value of the FCF in this situation.

The invention is illustrated by schemes for determining coordinates, illustrating the proposed method.

Figure 1 presents a complex of passive locations of the whole composition (RTP≥5) all-round visibility. In the spatial domain — the gate of the PBO location (in the diagram — the polygon), calculated by the triangulation method in the first stage, the position of the PBO by the intersection point of the hyperboloids is refined using the hyperbolic method in the second stage (in fact, it is also the gate, but it is ten times smaller). To obtain the full vector of the target’s position in space in a Cartesian coordinate system and oblique range (x, y, z and R), it is necessary to intersect from 4 or more hyperboloids.

Figure 2 presents a complex of passive locations of incomplete composition (RTP≤4). In this case, although a circular view is maintained, the resulting target position vector is incomplete. Contains only two Cartesian coordinates and slant range. To obtain the 3rd coordinate, vector data for oblique range or goniometric method are used. In the latter case, the target location point in space is the intersection point of 3 hyperboloids and one azimuthal plane.

Figure 3 presents the complex of passive location of the minimum composition (RTP = 3). In this case, only a sector review is possible (two sectors of 60 ... 80 degrees). The resulting target position vector is also incomplete. Contains one Cartesian coordinate and slant range. To obtain the 2nd and 3rd coordinates, the data of the goniometric method using the azimuth and elevation angle of the target are used. The location point of the target in space in this case is the intersection point of 2 hyperboloids, one azimuthal plane and the conical surface of the elevation angle of the target.

Figure 4 presents a complex of passive location of the minimum composition (RTP = 3), illustrating the zone of "aging" of the data obtained from calculating the strobe in a triangulation way, from σ to 3σ. To implement the hyperbolic method, the time interval for which it must be implemented is determined. This time interval is calculated as

Δτ _s = σ ... 3σ / V _PBO ,

where V _PBO is the module of the target’s flight speed.

The basis for the achievement of the technical effect is the preservation of the main advantage of the triangulation method for determining the location of the VVO - the high throughput of the passive location system for the “maintenance” of radio emission sources in combination with the high accuracy of determining the location of all or specified radio emission sources using the hyperbolic (triangulation-hyperbolic) method. The formation of the gate of the position of the PBO potentially provides a sharp reduction in intermediate calculations to find the desired difference in the time delay of the signal between the CPU and the PCB.

The effectiveness of the proposed method was verified by modeling in a Mathcad-15 environment using the following example:

a) the throughput of the KPL, which implements the differential-ranging method of passive location determining the location of the PBO;

b) The capacity of the CPL that implements the proposed method of the 2-stage triangulation-hyperbolic method for determining the location of the PBO.

As the investigated variant of the passive location complex, we considered a complex consisting of a CPP and three peripheral PPs located in the azimuthal plane from each other through 120 degrees. and thus forming the correct 3-ray star (Figure 2). It should be noted that in order to exclude additional errors when using the differential-ranging method at ranges significantly exceeding the value of the bases due to the straightening of the hyperbolas and their coincidence with their asymptotes, the ratio of the range to the PBO and the base distance was limited to 10 times. In this regard, in the near zone at a distance of up to 100 km, the base value was 10 km, and in the far zone up to 400 km, respectively, 40 km. In order to simplify the calculations and their volume, the RVO was considered as an over-horizon object with a constant elevation value from the central control center equal to 5 deg. and independent of the range of the target. In other words, the RVO flight was simulated on a certain inclined plane.

To conduct adequate research, it was enough to consider the possible positions of the VBO in one quarter of the azimuthal plane. I quarter was chosen as such a quarter. The possible angular positions of the emitting object, which cover the entire range of differences in the signal path, from 0 to two basic distances between the CPT and any PP, were adopted as possible positions of the PBO. Thus, in the conducted studies, the VBOs were located uniformly over the azimuth range from 0 to 90 degrees. at distances of 100 km (near zone) and 400 km (far zone).

The value of the resolution element as a delay compensation step was 10 ns, which corresponded to an error in a single primary measurement of the difference in the signal path - 3 m. The value of this value was chosen in accordance with the implemented analog devices / ERA a.s. Prumyslová 387, 530 03 Pardubice, Gzech Republic, 2004, “Foreign Military Review”, Moscow: Military Publishing House, 1995, No. 7, “Foreign Military Review”, Moscow: Military Publishing, 2001, No. 91.

At each current position of the PBO:

- the difference in the signal path between the CPP and each PP was determined;

- as a result of obtaining estimates of position coordinates, the components of the strobe size were determined by a triangulation method.

For a CPL using the differential-ranging method for determining the location of the PBO (option “a”), the processing of signals in correlation meters (by the meter at each base) must be carried out by rebuilding the special device according to the delay compensation steps until a global one is obtained maximum cross-correlation function (VKF) at the output of the correlator, including taking into account the weight processing, if necessary in this situation. Therefore, the quotient obtained from the simulation of dividing the difference in the signal path between the CPU and any PP by the delay compensation step (resolution element) of the tunable special device for compensating the signal difference corresponds to the value of the number of required delay compensation steps for the desired special device to obtain the desired result ( max VKF) on this measuring base

In the proposed method (option "b"), the location of the PBO is measured using the goniometric-differential-ranging method in the strobe formed by the triangulation method, its components, as noted above, are determined by the rule of 3 σ. In this case, the lower boundary of the delay time interval in the strobe is determined for negative values of the constituent dimensions of the strobe (i.e., in Cartesian coordinates, these are the values of σx, σy, and σz PBO, and in the polar coordinates σR, σβ, and σε PBO), and the upper with positive values. Thus, a delay time interval is formed within the 3σ boundaries that make up the triangulation strobe, inside of which there is the desired signal delay value, which ensures the global maximum of the SCF.

During the simulation, it was assumed that the direction finding of the RVO is carried out by the single-pulse amplitude method, by the antennas of the RTP. At the same time, high-potential radio engineering stations are used as RTP either with mechanical scanning of antennas in azimuth (Product 86V6A-SOP, developed by ZAO SPP Special Radio, Belgorod, 2000), or with electronic scanning of antennas in azimuth Product Corsair , developer of CJSC SPE Special Radio, Belgorod, 2011), providing root-mean-square errors (RMS) of primary measurements of angular coordinates:

- 0.5 deg. in azimuth;

- 1.0 deg. by the corner of the place.

Obtaining estimates of the spatial coordinates calculated by triangulation and hyperbolic methods was carried out in accordance with the above algorithms, as well as / Scientific and technical report on research work "Design and search work to substantiate the technical appearance of a goniometric-hyperbolic complex of passive location", Belgorod, NPP CJSC Special Radio, 2007 /.

As an example, confirming the advisability of using a 2-stage determination of the coordinates of the PBO, consider the following.

In accordance with the given initial data on the composition, characteristics of the KPL and VBO, as well as calculation algorithms, we obtain:

1st stage of measurements (triangulation method) obtaining a strobe:

- at a distance of 100 km - standard deviation of range ≈9 km and standard deviation of azimuth ≈3 deg,

- at a distance of 400 km - standard deviation of range ≈33 km and standard deviation of azimuth ≈0.3 deg.

2nd stage of measurements (hyperbolic method) clarification of the position in the strobe:

- at a distance of 100 km - RMS range ≈0.45 km and azimuth ≈0.3 degrees;

- at a distance of 400 km - at a distance of ≈0.96 / cm and azimuth ≈0.3 degrees.

Thus, as a result of a computational experiment for one purpose, the following data were obtained:

- for the KPL of option “a” using the differential-ranging method for determining the location of the VBO, the number of resolution zones viewed was more than 13 billion;

- KPL of option “b” with the proposed triangulation-hyperbolic method for determining the location of the RVO; the number of resolution zones viewed was 35 million.

The technical result in the KPL with the proposed triangulation-hyperbolic method for determining the location of the RVO was 3.7 orders of magnitude compared to the KPL using the differential-range measuring method for determining the location of the RVO. Consequently, a significant increase in the capacity of the CPL with the simultaneous calculation of the exact coordinates of the location of the RVO (at the level of the angular-hyperbolic method) for any composition of the receiving points in the complex has been proved.

Thus, the problem facing the invention is solved.

Claims (1)

The triangulation-hyperbolic method for determining the coordinates of radio-emitting air objects in space, characterized in that at all receiving points: at one central and several peripheral points, measure the angular coordinates of the radio emission source and the distance difference between the central and peripheral receiving points, the coordinates are determined in two stages: at the first stage, the gate of the location of the radio emission source obtained on the basis of the measured the angular coordinates of this source by the central and all peripheral receiving points, and in the second stage, using the hyperbolic method, in the resulting strobe, the distance differences between the central receiving point and all peripheral receiving points are calculated and the exact location of the radio source in space is determined, with each a peripheral receiving point for measuring the difference of the delay time of the signal upon command from the central point establish a bearing on the radio-emitting air an object for fulfilling the conditions for receiving the same signal by all receiving points.

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