RU2558639C2 - Dichotomous multiplicative difference-relative method for mobile determination of coordinates of position of radio-frequency source - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to radio monitoring systems for determining the position of radio-frequency sources. The method is based on using measurements by a mobile radio monitoring station of signal strength values at each of assigned frequencies at three points in space and conversion into paired multiplicative difference of inverse ratios thereof and ratios of distances from measurement points to the radio-frequency source. A dichotomous method is employed to process the multiplicative differences of said ratios. The method is based on the principle of consecutive determination of parameters of the position of the radio-frequency source: latitude Xi, longitude Yi and altitude Zi based on the criterion of searching for the minimum of the differences of ratios of the distance of the position of the radio-frequency source to measurement points which are not located on the same line, and corresponding inverse ratios of the measured signal strength values.

EFFECT: determining spatial coordinates of the position of fixed radio-frequency sources with one mobile radio monitoring station.

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Description

The invention relates to the field of radio engineering, and in particular to radio monitoring systems for determining the spatial location of stationary sources of radio emission (IRI), information about which is not in the database (for example, state radio frequency services or state communication supervision services). The invention can be used in the search for the location of unauthorized means of radio communication, as possible sources of communication interference.

Known methods for determining the coordinates of the IRI, in which passive direction finders are used in an amount of at least three, the center of gravity of the region of intersection of the revealed azimuths of which at the wave arrival front is taken as the location estimate. The basic principles of operation of such direction finders are amplitude, phase, and interferometric [1, 2]. Their disadvantages include a high degree of complexity of antenna systems, switching devices and the presence of multi-channel radios, as well as the need for high-speed information processing systems.

The presence in the federal districts of the state radio frequency service interconnected through a central point of an extensive network of radio monitoring posts equipped with means for receiving radio signals, measuring and processing their parameters, allows you to supplement their functions and tasks of determining the location of those IRI, information about which is not available in the database, without resorting to use complex and expensive direction finders. Of the known methods, the closest analogue (prototype) of the proposed method according to the technical essence is the method [3], which consists in receiving signals from radio sources in the frequency band ΔF moving in space meter. When moving the meter, signal levels are measured at N (N≥4) points, N-1 signal level ratios are successively calculated, N-1 circular position lines are constructed from the calculated ratios and the coordinates of the radio emission sources are determined as the intersection point of N-1 circular position lines. To increase the reliability of the location using statistics.

The main disadvantages of the prototype.

1. Algorithmic inconsistency and incompleteness of its implementation in time. Indeed, the statement about finding the coordinates of the sources of radio emission as the intersection point of N-1 (N≥4) circular position lines contradicts the need to refine these coordinates by statistical means. Since N in the claims is not limited from above, the coordinates of the IRI as the coordinates of the intersection point of an unlimited number of circular position lines will be determined with unlimited high accuracy. And, therefore, they do not need statistical refinement. But, if it is argued that a statistical specification of the location is necessary, then the possibility of crossing at one point an unlimited number of circular position lines is denied. And the latter is closer to reality, since there are no instruments and methods of measurement with unlimited high accuracy.

2. The fundamental difficulty of finding the coordinates of the intersection point of N-1 (N≥4) circular position lines by directly solving the system of equations describing them. Indeed, according to [4, p.66], the general equation of a circle in Cartesian rectangular coordinates has the form:

x ² + y ² + Ax + By + C = 0.

And at the same time, “all circles passing through real or imaginary intersection points of two circles are determined by the equation:

where λ is the parameter. "

Let circles be given by the equations:

This system of three equations of any circles, including Apollonius, which was mentioned in [3], has one solution, that is, circles intersect at one point only if the determinant of the system is zero. And this is possible, according to [4, p.66], if one of the three equations is obtained from the other two in this way. Moreover, the coefficients of this derivative equation, let it be the Scd equation for definiteness, should be defined as:

A3 = (A1 + λA2) / (1 + λ), B3 = (B1 + λB2) / (1 + λ), C3 = (C1 + λC2) / (1 + λ).

The determinant of such a system

indeed, it is equal to zero, and therefore, the third circle can pass through the intersection point of the first two circles only with a strictly defined connection with them.

The previous statement is also supported by the statement based on the fact that arcs of circles in the neighborhood of the point of their intersection (or tangent to circles at this point) can be considered as three intersecting lines. In this regard, according to [4, p. 59, item g], the statement: “In order that the three lines A1x + B1y + C1 = 0, A2x + B2y + C2 = 0, A3x + B3y + C3 = 0 intersect at one point or were parallel, it is necessary and sufficient that

those. so that the left-hand sides of the equations are linearly dependent, ”it really reinforces the previous statement. The solution of the system of equations of three circles without imposing these conditions can be achieved, but only on other principles, one of which, as the simplest, is proposed by the authors of this application.

3. The number of measurement points for signal levels N≥4, which is redundant to obtain a single reference coordinate location.

4. The presence of the singularity of circular position lines (Apollonius of Perga circles) at close values of signal levels at the points of measurement, leading to a large error in determining the coordinates of the location of the IRI.

5. The prototype does not allow to determine the location coordinates of spatial IRI.

The aim of the present invention is to develop a method for determining location coordinates at existing radio monitoring posts of the Radio Frequency Service of the Russian Federation, which eliminated the disadvantages of the prototype.

попарных мультипликативных уравнений разностей

попарных отношений расстояний от точек измерения до местоположения искомого источника радиоизлучения, полученных для заданных из известного диапазона значений широт, долгот и высот искомого местоположения источника радиоизлучения, и

соответствующих попарных обратных отношений величин уровней сигналов источника, а также составляют

мультипликативных уравнений таких же разностей отношений для всех точек измерения, взятых по три, дихотомически изменяют последовательно значение каждого из параметров местоположения источника радиоизлучения при неизменных значениях двух других и находят точки экстремумов

мультипликативных уравнений каждой пары точек измерения и точки перегиба

мультипликативных уравнений для всех точек измерения, взятых по три, фиксируя после суммарного N кратного

усреднения каждый найденный в этих точках параметр местоположения источника, как окончательный.This goal is achieved using the features specified in the claims common to the prototype: a method based on measuring the levels of radio emission signals at several points in space that are not lying on one straight line by scanning radio receivers moving in space, and distinguishing features: for measuring signal levels of radio emissions IRI use M≥3 measurement points located in the zone of electromagnetic accessibility of the post, make up

pairwise multiplicative difference equations

pairwise relationships of the distances from the measurement points to the location of the desired source of radio emission obtained for a given from a known range of latitudes, longitudes and heights of the desired location of the source of radio emission, and

the corresponding pairwise inverse relations of the values of the signal levels of the source, and also

multiplicative equations of the same difference of relations for all measurement points taken in three, dichotomously sequentially change the value of each of the parameters of the location of the source of radio emission at constant values of the other two and find the points of extrema

multiplicative equations for each pair of measurement points and inflection points

multiplicative equations for all measurement points taken in three, fixing after the total N multiple

averaging each source location parameter found at these points as final.

Затем вычисляют попарные отношения этих расстояний

,

,

и т.д., всего

отношений. Эти отношения позволяют исключить зависимость вычисления координат местоположения от мощности ИРИ. Полученные отношения сравнивают путем вычитания с обратными отношениями уровней сигналов:The method is based on the principle of sequentially determining the parameters of the PXR location: latitude - Xi, longitude - Yi and height Zi according to the criterion of the minimum difference in the relationship of the distance of the IRI location to each of the corresponding measurement points and the corresponding inverse relations of the signal levels measured at these points. The coordinates can be calculated by the method of dichotomy, for example, the method of bitwise balancing. For its use, a priori, the ranges of D values of the sought quantities must be known. These ranges are usually known based on the parameters of the electromagnetic accessibility zone of the used mobile monitoring posts. In accordance with the bitwise balancing algorithm, the average of the range D is initially set to the value of the determined value (for example, latitude) for fixed, but lying in known ranges of values of longitude and height. Calculate the distance from the i-th location of the IRI to each j-th measurement point (j≤3),

Then calculate the pairwise ratios of these distances

,

,

etc., total

relationship. These relationships make it possible to eliminate the dependence of the calculation of location coordinates on the power of the IRI. The resulting relationships are compared by subtracting the signal strengths with the inverse ratios:

,

,

и т.д., всего

отношений.

,

,

etc., total

relationship.

, где m - количество итераций. На рис.1 показано изменение этих функций для всех трех пар точек измерения при последовательном, равномерно-ступенчатом (для наглядности) поиске. После этого фиксируют полученное значение параметра. Затем аналогично вычисляют значение долготы при найденной широте, а затем и высоты. Отметим, что данный способ для одной пары точек измерения может иметь неоднозначность результата. Устраняют ее путем нахождения экстремумов каждой из функций попарных произведений разностей отношений (для каждой из двух пар точек измерений), например, 1, 2 и 2, 3: F_212.23=(n_12i-n₂₁)(n_23i-n₃₂), 1,2 и 3,1 - F_212.31=(n_12i-n₂₁)(n_13i-n₁₃), 2, 3 и 3, 1 - F_223.31=(n_23i-n₂₃)(n_13i-n₃₁) и т.д. всего

уравнений, или, что предпочтительнее, путем нахождения точек перегиба функции произведения трех разностей отношений для точек измерения 1, 2 и 3 F₃₁₂₃=(n_12i-n₂₁)(n_23i-n₃₂)(n_31i-n₁₃), всего

уравнений, для M точек измерения.For example, for measurement points 1 and 2, this difference is defined as F ₁₁₂ = (n _12i -n ₂₁ ). For 2 and 3 - as F ₁₂₃ = (n _23i -n ₃₂ ), etc. If the difference in relationship is less than zero, then 1/4 of the range is added to the original latitude value. Otherwise, 1/4 of the range of its value is subtracted from the original latitude value. Then again calculate the distances to the posts and evaluate the results of the comparison, as described above. In this case, 1/8 of the range is added (or subtracted), then 1/16 of the range, etc. Such iterations continue until the result of the comparison is in absolute value less than a predetermined value of the sampling error of each location parameter

where m is the number of iterations. Figure 1 shows the change in these functions for all three pairs of measurement points in a sequential, uniformly-stepped (for clarity) search. After that, the obtained parameter value is fixed. Then, similarly calculate the value of longitude at the found latitude, and then the height. Note that this method for one pair of measurement points may have an ambiguous result. Eliminate it by finding the extrema of each of the functions of the pairwise products of the difference of the relations (for each of the two pairs of measurement points), for example, 1, 2 and 2, 3: F _212.23 = (n _12i -n ₂₁ ) (n _23i -n ₃₂ ), 1,2 and 3,1 - F _212.31 = (n _12i -n ₂₁ ) (n _13i -n ₁₃ ), 2, 3 and 3, 1 - F _223.31 = (n _23i -n ₂₃ ) (n _13i -n ₃₁ ) etc. Total

equations, or, more preferably, by finding the inflection points of the product function of the three difference relations for the measurement points 1, 2 and 3 F ₃₁₂₃ = (n _12i -n ₂₁ ) (n _23i -n ₃₂ ) (n _31i -n ₁₃ ), total

equations for M measurement points.

Figure 1 shows the dependencies of the differences of relations for each pair of measurement points, figure 2 - for the product of two pairs of measurement points, figure 3 - the product of differences of relations for three pairs.

So, algorithmically, the method involves the following operations:

1. Measure at least three points in the trajectory of the mobile monitoring post, not lying on one straight line and located in the electromagnetic accessibility zone of the post, the IRI signal levels by tuning the scanning receiver of this post to the carrier frequencies and storing the measurement results and coordinates of the points in the database level measurement.

2. The ratios of the measured IRI signal levels are calculated that are inverse to the ratios of the corresponding distances from M measurement points to the possible location of the IRI.

попарных мультипликативных уравнения разностей попарных отношений расстояний от точек измерения уровней до возможного местоположения ИРИ и соответствующих обратных отношений измеренных уровней, а также

мультипликативных уравнений для всех M точек измерения уровней, взятых по три.3. Make up

pairwise multiplicative equations of differences of pairwise relations of distances from measuring points of the levels to the possible location of the IRI and the corresponding inverse relations of the measured levels, and

multiplicative equations for all M level measuring points taken in three.

попарных мультипликативных уравнений с заданной погрешностью не достигнет экстремального значения, а также каждое из

мультипликативных уравнений для каждой тройки точек измерения уровней не достигнет точки перегиба.4. Two coordinate parameters (for example, longitude and height) are set from a known range of coordinates of the possible location of the IRI, and one of the coordinate parameters (for example, latitude) is dichotomously changed and the possible distance of the IRI to each of the points of the measurements taken is then calculated while each of

pairwise multiplicative equations with a given error does not reach an extreme value, and also each of

the multiplicative equations for each triple of level measurement points will not reach the inflection point.

5. The values of the parameters obtained at extreme points and inflection points are averaged and taken as final.

6. Procedures for PP. 4 and 5 are repeated to sequentially obtain the longitude, and then the height of the location of the desired IRI.

In the proposed method, the disadvantages of the prototype are eliminated:

1. Excluded are any complex equations of the Iranian location lines with hidden singularity errors. In the proposed method, the functions of the product of the difference in the ratios of the finite quantities (distances and inverse levels of the signals) are smooth and do not create singular errors.

2. The proposed method provides the determination of the coordinates of the location of the IRI not only on the Earth's surface, but also in space.

3. The minimum number of measurement points is reduced from four to three, which indicates an increase in the speed of the method compared to the prototype.

, что позволяет повысить точность определения координат местоположения источника радиоизлучения по сравнению с прототипом. Ниже приведена сопоставительная таблица количества усреднений для заявляемого способа и прототипа, подтверждающая более высокую точность предложенного способа.4. For the number of measurement points M≥3, the total number of averagings is equal to

that improves the accuracy of determining the coordinates of the location of the source of radio emission in comparison with the prototype. The following is a comparative table of the number of averagings for the proposed method and prototype, confirming the higher accuracy of the proposed method.

Number of measuring points for fasting levels 3 four 5 6 Prototype - one 5 fifteen The inventive method four 10 twenty 35

All this indicates the novelty of the proposed method.

It should be noted that the method is the most universal, does not require complex calculations and is easily implemented.

Information sources

1. Reference for radio monitoring. International Telecommunication Union. - Geneva: Radiocommunication Bureau. 2002 .-- 585 p.

2. Korneev I.V., Lentsman V.L. and others. Theory and practice of state regulation of the use of radio frequencies and RES civilian applications. The collection of materials of continuing education courses for specialists of radio frequency centers of federal districts. Book 2. - SPb .: SPbSUT. 2003.

3. Patent RU No. 2306579, publ. September 20, 2007

4. E. Korn and T. Korn. Math reference. For scientists and engineers. / Ed. Aramanovich I.G. - M .: "Science". 1968 .-- 720 s.

Claims (1)

A dichotomous differential-relative method for mobile determination of the coordinates of the location of a source of radio emission, based on measuring the parameters of radio emissions at several points in space that are not lying on one straight line by scanning radio receivers moving in space, and characterized in that M≥3 points are used to measure the parameters of radio emissions from IRI measurements of signal levels of radio emissions in the zone of electromagnetic accessibility of the post are $${\mathrm{FROM}}_M^2$$

pairwise multiplicative difference equations $${\mathrm{FROM}}_M^2$$

pairwise relationships of the distances from the measurement points to the location of the desired source of radio emission obtained for a given from a known range of latitudes, longitudes and heights of the desired location of the source of radio emission, and $${\mathrm{FROM}}_M^2$$

the corresponding pairwise inverse relations of the values of the signal levels of the source, and also $${\mathrm{FROM}}_M^3$$

multiplicative equations of the same difference of relations for all measurement points taken in three, dichotomously sequentially change the value of each of the parameters of the location of the source of radio emission at constant values of the other two and find the points of extrema $${\mathrm{FROM}}_M^2$$

multiplicative equations for each pair of measurement points and inflection points $${\mathrm{FROM}}_M^3$$

multiplicative equations for all measurement points taken in three, fixing after the total N multiple $$(N={\mathrm{FROM}}_M^2+{\mathrm{FROM}}_M^3)$$

averaging each source location parameter found at these points as final.

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