RU2206104C2 - Method for identification of distant aerial objects - Google Patents

Abstract

FIELD: identification of distant aerial objects above water areas bordering on zones of sea ports. SUBSTANCE: in agreement with method for identification of distant aerial objects azimuth and range to identified object are measured by two double- coordinate radars, coordinates of identified object are evaluated by measurement data, data on trajectory of conditional surface object flying at specified altitude along projection of trajectory of identified object on horizontal plane are entered by way recalculation. Vector of data on measurements of azimuth and range to identified object is formed and recorded, vector of recalculated data is formed, vector of random measurement errors is formed, sums of recorded data vectors and vector of random measurement errors are formed and data array of evaluated altitudes of flying of identified object and data array of evaluated altitudes of flying of conditional surface object are formed on their basis. Histograms of data arrays of evaluated altitudes of flying of identified and conditional surface objects are constructed, frequency of fall of evaluations of altitude of identified object to space above average value of data array of evaluated altitudes of conditional surface object is determined and compared with threshold value equal to frequency of fall of evaluations of altitude of conditional surface object to space above average value of array of evaluated altitudes of conditional surface object. Conclusion on identification in distant object of aerial object is formed if frequency of fall of evaluations of altitude of identified object to space above average value of array of evaluated altitudes of conditional surface object exceeds threshold value equal to fall of evaluations of altitude of conditional surface object to space above average value of array of evaluated altitudes of conditional surface object. EFFECT: expanded space of identification of aerial objects. 6 dwg

Description

 The invention relates to the field of traffic control of marine vessels and is intended for recognition (separation) of distant airborne objects in an array of radar marks (objects) obtained by a joint radar survey by two two-coordinate (azimuth, distance to the target) radar stations of the marine area with moving sea vessels, over which move airborne vehicles (airborne objects).

 One of the features of modern maritime transport is the collective nature of movement, which often, especially in areas of transport routes adjacent to ports, takes the form of multidirectional flows with limiting values of the intensity and dynamism of movement of marine objects, which requires safety in order to make management decisions in marine traffic control systems in a timely manner (from the moment of detection of objects at large distances) take measures to recognize air objects in the array of radar marks and exclude them from the number of objects that make dangerous proximity with marine vessels (false emergencies) that require management intervention High-speed air objects in marine traffic control systems are recognized as air objects by the difference in their estimated speeds in comparison with speed of surface objects. However, if the speed of the airborne object is low (helicopters, air probes, flocks of birds, etc.) and is commensurate with the speed of high-speed surface objects (boats and hovercraft, hydrofoils), then an air object should be recognized in a remote object by comparing its estimated height of movement with the estimated height of movement, for example, a surface object, the height of the center of the radar reflectors of which is known in advance. It is this approach that is implemented in the inventive method for recognizing remote air objects.

 Motion control systems for ships (including at least two two-coordinate radar stations) in areas adjacent to ports, in addition to determining the coordinates of surface objects in the horizontal plane, can also evaluate the height of the center of radar reflectors of a recognized object above sea level using special algorithms, hereinafter referred to as the height of movement of the recognized object. Recognized objects are divided into air objects and surface objects, the latter include sea vessels. At a surface object, the center of its radar reflectors is located at a certain height above sea level. The magnitude of this height, as well as the height of the radar reflectors of an airborne object, is estimated with errors. With increasing distance of the recognizable object from the radar stations, the ratio of the height of the recognized object to its removal decreases. This leads to a violation of the optimal modes of estimation algorithms and, accordingly, to an increase in height estimation errors and false conclusions regarding recognition of an air target in an object, i.e. remote airborne objects are not recognized.

 As a result, the recognition space of airborne objects is limited in distance (areas of large distances are excluded), i.e. remote airborne objects are not recognized.

 Thus, the problem of recognizing remote airborne objects in an array of recognizable objects remains unresolved based on comparing the frequency of falling estimates of the height of recognizable objects in space above the average value of the array of estimated heights of the conditional surface object with a threshold value equal to the frequency of falling estimates of the height of the conditional surface object in space above the average values of the array of estimated heights of the conditional surface object moving at a given height along the projection of the trajectory recognizing the object to the horizontal surface. In this case, as a known surface object, we consider a conditional surface object that in physical reality does not exist, but we introduced it into the situation under consideration to provide controlled conditions for comparison, when we specify the height of the conditional surface object and, therefore, we know other characteristics ( the trajectory in the horizontal plane) of the conditional surface object coincides with the characteristics (the trajectory in the horizontal plane) of the recognized object, which ensures the situation when two compared objects (recognizable and conditional surface) differ only in the height of movement, which allows statistically (based on a comparison of the frequencies of falling height estimates) to establish a difference in the heights of their (recognized and conditional surface) movement and formulate a conclusion regarding the belonging of the recognized object to the class of air objects.

 The absence of recognition of distant air objects in marine traffic control systems based on a comparison of the frequency of falling estimates of the height of recognizable objects in space above the average value of the array of estimated heights of the conditional surface object with a threshold value equal to the frequency of falling estimates of the height of the conditional surface object in space above the average value of the array of estimated heights of the conditional surface object moving at a given height along the projection of the trajectory of the recognized object on g rizontalnuyu surface narrows the space reliable detection of air objects (exclusive domain of large deletions).

 The presence of recognition of an air target based on a comparison of the frequency of falling estimates of the height of recognizable objects in space above the average value of an array of estimated heights of a conditional surface object with a threshold value equal to the frequency of falling estimates of the height of a conditional surface object in space above the average value of an array of estimated heights of a conditional surface object moving on a given height on the projection of the trajectory of the recognized object on a horizontal surface, allows in an array of recognizable objects to recognize remote aerial objects in the case when the frequency of falling estimates of the height of recognizable objects in space is higher than the average value of the array of estimated heights of the conditional surface object exceeds the threshold value equal to the frequency of falling estimates of the height of the conditional surface object in space above the average value of the array of estimated heights of the conditional surface object moving at a given height on the projection of the trajectory of the recognized object on a horizontal plane.

 Ultimately, the presence of recognition of distant airborne objects based on a comparison of the frequency of occurrence of estimates of the height of recognizable objects in space above the average value of the array of estimated heights of the conditional surface object with a threshold value equal to the frequency of the occurrence of estimates of the height of the conditional surface object in space above the average value of the array of estimated heights of the conditional surface object a surface object moving at a given height according to the projection of the trajectory of the recognized object on a horizontal surface, It allows you to expand the recognition space of airborne objects (including areas of large distances) and to recognize distant airborne objects.

 A device is known "three-coordinate radar system" [1], which implements a method based on the calculated height of the object, containing two two-coordinate radar, with which (based on the measurement of azimuth and distance to the object) the third coordinate is calculated - the height of the object.

 The main disadvantage of the method implemented using the "Three-coordinate radar system" device is that they determine the height of movement of objects based on trigonometric calculations and, therefore, determine with significant errors the height of movement of distant objects, for which the ratio of their height to distance from radar system (which is typical for remote recognizable objects) due to the increasing influence of measurement errors performed by two-coordinate radar nnym stations, the accuracy of calculating the height of distant objects For this reason, the computed altitude motion of remote air and surface objects take comparable values that excludes significant separation recognizable on distant objects and aspirating air (surface). At the same time, this method does not provide the ability to recognize remote aerial objects by comparing the frequency of falling estimates of the height of recognizable objects in space above the average value of the array of estimated heights of the conditional surface object with a threshold value equal to the frequency of falling estimates of the height of the conditional surface object in space above the average value an array of estimated heights of the conditional surface object moving at a given height according to the projection of the trajectory of the recognized object on the horizontal level ground.

 Therefore, this method, implemented by the analog device "three-coordinate radar system", for this reason, cannot be used to recognize remote air objects in the array of recognizable objects and does not allow to expand the recognition space of air objects (including areas of large distances).

 There is also known a method of “combining estimates of two-dimensional search sensors” [2], based on a comparison of the estimated height of the movement of recognized objects with the estimated height of surface objects. The method includes measuring the azimuth and distance to a recognizable object by two radar stations, estimating from the measurement data the coordinates (including height) of the object.

 According to this method, the height of the movement of an air object is estimated by the algorithmic method, which is the optimal combination of estimates by two Kalman filters using the same model, but different sets of measurements of the position of the object. Kalman filters work on measurements from two radar stations, and their outputs are combined in a non-linear optimal way.

 For unrecognized recognized objects, the error in estimating the height is small and does not affect the reliability of the results of object recognition: the estimated altitudes of the movement of the air and surface objects are clearly distinguished. However, with increasing distance of the recognized object from radar stations, the ratio of its true height to distance decreases. This leads to a violation of the optimal modes of the estimation algorithm and, accordingly, to an increase in height estimation errors. For this reason, the obtained estimates of the height of movement of remote air and surface objects take comparable values, which excludes a reliable separation of the detected remote objects into surface and air. However, at the same time, a device that implements the method of “combining estimates of two-dimensional search sensors” does not provide the ability to recognize remote aerial objects based on a comparison of the frequency of falling estimates of the height of recognizable objects in space above the average value of the array of estimated heights of the conditional surface object with a threshold value equal to the frequency of falling estimates heights of the conditional surface object into space above the average value of the array of estimated heights of the conditional surface object moving to the rear the given height on the projection of the trajectory of the recognized object on a horizontal surface, which eliminates reliable recognition when implementing the analogue method of remote air objects and, as a result, narrows the recognition space of air objects, i.e. areas of large deletions are excluded.

 Thus, the known method of “combining estimates of two-dimensional search sensors” for this reason cannot be used to recognize remote marine and airborne objects in an array of recognizable objects and does not allow to expand the recognition space of airborne objects (including areas of large distances).

 The known method of "combining estimates of two-dimensional search sensors", in its technical essence, functionality and technical result achieved, is closest to the claimed invention for a method for recognizing remote air objects and will be considered hereinafter as a prototype method.

 The basis of the invention is the creation of a method for recognizing remote airborne objects based on a comparison of the frequency of occurrence of estimates of the height of recognizable objects in space above the average value of an array of estimated heights of a conditional surface object with a threshold value equal to the frequency of occurrence of estimates of the height of a conditional surface object in space above the average value of an array of estimated surface objects heights of the conditional surface object moving at a given height along the projection of the trajectory of the recognized object on the mountain ontalnuyu surface, in order to increase recognition of air space objects, thus including areas of large deletions.

 The problem is solved in that in the method of recognition of remote airborne objects, in which the azimuth and distance to the recognized object are measured by two two-coordinate radar stations, the coordinates of the recognized object are estimated from the measurement data, data on the trajectory of the conditional surface object are additionally entered by recalculating the estimated horizontal coordinates of the recognized object in azimuth and distance from each radar station to a conventional surface object moving at a given height along the projection of the trajectory of the recognized object on a horizontal plane, form and store a vector of measurement data from two radar stations about the azimuth and distance to the recognizable object containing all measurements from the moment of detection to the current moment, as well as a vector containing all recalculated data from the moment of detection of a recognized object up to the current moment about the azimuth and distance from two radar stations to a conventional surface object moving at a given height along the projection and the trajectories of the recognizable object on a horizontal surface, form a vector of random measurement errors, the structure and length of which is consistent with the stored data vectors, form the sum of the stored data vectors and the vector of random measurement errors and perform them on the basis of multiple calculations, after each new measurement of the coordinates of the recognized object , the formation of an array of estimated heights of movement of a recognized object, as well as an array of estimated heights of movement of a conditional surface object, motion After projecting the estimated trajectory of the recognized object onto the horizontal plane, at each given height, after each new measurement of the coordinates of the recognized object, histograms of the arrays of the estimated movement heights of the recognizable and conditional surface objects are built, and the frequency of estimates of the height of the recognized object falling into space above the average value is determined and compared based on the histograms an array of estimated heights of a conditional surface object with a threshold value equal to the frequency of falling height estimates conditional surface object into space above the average value of the array of estimated heights of the conditional surface object moving at a given height along the projection of the trajectory of the recognizable object on a horizontal surface, and form a conclusion on the recognition of an air object in a remote object in the case when the frequency of falling estimates of the height of the recognizable object in the space above the average value of the array of estimated heights of the conditional surface object exceeds a threshold value equal to the frequency of the fall of sc Conditional knock freeboard height of the object in the space above the medium array value estimated conditional freeboard heights of an object moving at a predetermined height on the projection trajectory recognized object on a horizontal surface.

In the claimed method for the recognition of remote air objects, the common essential features for him and for his prototype method are:
- measurement of azimuth and distance to a recognized object by two two-coordinate radar stations;
- estimation according to the measurement data of the coordinates of the recognized object.

A comparative analysis of the essential features of the claimed method and the prototype method shows that the first, in contrast to the prototype method, has the following significant distinguishing features:
- data input on the trajectory of a conditional surface object by recalculating the estimated horizontal coordinates of the recognized object in azimuth and the distance from each radar station to the conditional surface object moving at a given height along the projection of the trajectory of the recognized object on a horizontal plane,
- the formation and storage of a vector of measurement data from two radar stations about the azimuth and distance to the recognizable object containing all measurements from the moment of detection to the current moment, as well as a vector containing all recalculated data from the moment of detection of the recognizable object to the current moment about azimuth and distance from two radar stations to the conditional surface object moving at a given height according to the projection of the trajectory of the recognized object on a horizontal surface,
- the formation of a vector of random measurement errors, the structure and length of which is consistent with the stored data vectors,
- the formation of the sum of the stored data vectors and the vector of random measurement errors and performing them on the basis of multiple calculations, after each new measurement of the coordinates of the recognized object, the formation of an array of estimated heights of movement of the recognized object, as well as an array of estimated heights of movement of the conditional surface object moving at a given height on the projection of the estimated trajectory of the recognized object on the horizontal plane,
- building after each new measurement of the coordinates of the recognizable object histograms of arrays of estimated heights of movement of the recognizable and conditional surface objects,
- determining and comparing, based on histograms, the frequency of falling estimates of the height of a recognizable object in space above the average value of an array of estimated heights of a conditional surface object with a threshold value equal to the frequency of falling estimates of the height of a conditional surface object in space above the average value of an array of estimated heights of a conditional surface object moving on a given height on the projection of the trajectory of the recognized object on a horizontal surface and the formation of a conclusion on recognition in the distance an airborne object in the case when the frequency of the estimated height of the recognized object falling into space above the average value of the array of estimated heights of the conditional surface object exceeds the threshold value equal to the frequency of the estimated height of the conditional surface object falling into space above the average value of the array of estimated heights of the conditional surface object, moving at a given height on the projection of the trajectory of the recognized object on a horizontal surface.

The set of features that ensure the achievement of a technical result:
- measurement of azimuth and distance to a recognizable object by two two-coordinate radar stations,
- evaluation according to measurements of the coordinates of the object,
- data input on the trajectory of a conditional surface object by recalculating the estimated horizontal coordinates of the recognized object in azimuth and the distance from each radar station to the conditional surface object moving at a given height along the projection of the trajectory of the recognized object on a horizontal plane,
- the formation and storage of a vector of measurement data from two radar stations about the azimuth and distance to the recognizable object containing all measurements from the moment of detection to the current moment, as well as a vector containing all recalculated data from the moment of detection of the recognizable object to the current moment about azimuth and distance from two radar stations to the conditional surface object moving at a given height according to the projection of the trajectory of the recognized object on a horizontal surface,
- the formation of a vector of random measurement errors, the structure and length of which is consistent with the stored data vectors,
- the formation of the sum of the stored data vectors and the vector of random measurement errors and performing them on the basis of multiple calculations, after each new measurement of the coordinates of the recognized object, the formation of an array of estimated heights of movement of the recognized object, as well as an array of estimated heights of movement of the conditional surface object moving at a given height on the projection of the estimated trajectory of the recognized object on the horizontal plane,
- building after each new measurement of the coordinates of the recognizable object histograms of arrays of estimated heights of movement of the recognizable and conditional surface objects,
- determining and comparing, based on histograms, the frequency of falling estimates of the height of a recognizable object in space above the average value of an array of estimated heights of a conditional surface object with a threshold value equal to the frequency of falling estimates of the height of a conditional surface object in space above the average value of an array of estimated heights of a conditional surface object moving on a given height on the projection of the trajectory of the recognized object on a horizontal surface and the formation of a conclusion on recognition an airborne object in the case when the frequency of the estimated height of the recognized object falling into space above the average value of the array of estimated heights of the conditional surface object exceeds the threshold value equal to the frequency of the estimated height of the conditional surface object falling into space above the average value of the array of estimated heights of the conditional surface object, moving at a given height on the projection of the trajectory of the recognized object on a horizontal surface.

 The technical result from the application of the claimed method for recognizing remote air objects is to expand the recognition space of remote air objects (the areas in which remote air objects move are included in the recognition space of air objects) by including in the number of recognized remote air objects, the calculated frequency of which height estimates fall into space above the average value of the array of estimated heights of the conditional surface object exceeds the threshold e value equal to the frequency of falling estimates of the height of the conditional surface object in space above the average value of the array of estimated heights of the conditional surface object moving at a given height along the projection of the trajectory of the recognized object on a horizontal plane.

 This set of known and distinctive essential features is sufficient and necessary to achieve the claimed technical result.

 Based on the foregoing, it can be concluded that the set of essential features of the claimed invention has a causal relationship with the technical result achieved, those due to this set of essential features of the invention, it became possible to solve the problem.

 Therefore, the claimed invention is new, has an inventive step, that is, it clearly does not follow from the prior art and is suitable for industrial use.

The essence of the claimed method for recognizing remote air objects is illustrated by the drawings:
figure 1 - diagram of operations that implement the method of recognition of remote air objects;
FIG. 2 is a diagram of the estimated movement height of a recognized object and the variance of its estimation errors for the prototype method;
FIG. 3 is a diagram of estimated elevations of movement obtained using the prototype method for a recognizable aerial object and a conditional surface object moving at a given height along the projection of the trajectory of the recognized object on a horizontal plane;
figure 4 is a histogram of an array of estimated heights of the conditional surface object for a certain distance r _j and a diagram of the average value of the estimated height of movement. Illustration of the excess of the shaded part of the diagram of the average value of the array of estimated heights of the conditional surface object;
FIG. 5 is a histogram of an array of estimated heights of a recognizable object for a certain distance r _j . Illustration of the excess of the shaded part of the diagram of the average value of the array of estimated heights of the conditional surface object;
FIG. 6 - frequency diagrams of falling estimates of the height of the recognizable and conditional surface objects in the space of heights above the average value of the array of estimated heights of the conditional surface object
The claimed method for recognizing remote airborne objects is implemented by operations 1 and 2 (Fig. 1) of measuring the azimuth and distance to a recognized object by two two-coordinate radar stations; operation 3 evaluation according to the measurement data of the coordinates of the recognized object; step 4 of entering data on the trajectory of a conditional surface object by recalculating the estimated horizontal coordinates of the recognized object in azimuth and the distance from each radar station to the conditional surface object moving at a given height along the projection of the trajectory of the recognized object on a horizontal plane; operation 5 of forming and storing a vector of measurement data from two radar stations about the measurement time, azimuth and distance to a recognizable object containing all measurements from the moment of detection to the current moment, as well as a vector containing all recalculated data from the moment of detection of the recognizable object to the current moment about recalculation time, azimuth and distance to the conditional surface object moving at a given height according to the projection of the trajectory of the recognized object on a horizontal plane ; step 6 of forming a vector of random measurement errors, the structure and length of which is consistent with the stored data vectors, and forming the sum of the stored data vectors and the vector of random measurement errors; an operation 7 of performing on the basis of the stored sums of vectors by repeated calculations after each new measurement of the coordinates of the recognizable object an array of estimated elevations of the recognized object’s motion, as well as an array of estimated elevations of the conditional surface object moving at a given height on the projection of the estimated path of the recognized object on a horizontal plane; step 8 of constructing, after each new measurement of the coordinates of the recognizable object, a histogram of an array of estimated elevations of the conditional surface object and determining after each new measurement of the coordinates of the recognizable object on the basis of the histogram of the frequency of the loss of estimates of the height of the conditional surface object in the height space above the average value of the array of estimated heights of the conditional surface object; step 9 of constructing, after each new measurement of the coordinates of the recognizable object, a histogram of an array of estimated elevations of the movement of the recognizable object and determining, after each new measurement of the coordinates of the recognizable object, based on the histogram of the frequency of falling estimates of the height of the recognizable object in the height space above the average value of the array of estimated heights of the conditional surface object; operation 10 of comparing the frequency of falling estimates of the height of the recognized object in space above the average value of the array of estimated heights of the conditional surface object with a threshold value equal to the frequency of falling estimates of the height of the conditional surface object in space above the average value of the array of estimated heights of the conditional surface object moving at a given height along the projection the trajectory of the recognized object on the horizontal plane and the formation of a conclusion on the recognition of an object in the case when the frequency of falling estimates of the height of the recognizable object in space above the average value of the array of estimated heights of the conditional surface object exceeds a threshold value equal to the frequency of falling estimates of the height of the conditional surface object in space above the average value of the array of estimated heights of the conditional surface object moving at a given height according to the projection of the trajectory of the recognized object on a horizontal surface.

 Implementation of the claimed method for the recognition of remote air objects by the motion control systems of marine vessels is as follows.

Two two-coordinate radar stations (radars) (operation 1 and 2, Fig. 1) detect a remote object at the limit for the radar data that needs to be recognized for its relationship to the class of airborne objects (hereinafter referred to as: "recognizable object"), and measure in exact time points of azimuth and distance to the object (φ $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pj}}$ , r $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pj}}$ , t $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pj}}$ - azimuth, distance and time, respectively, measured by the i-th radar, (i = 1,2), index p relates the measured parameters to the recognizable object, index j is the ordinal number of the space survey by the antenna of the corresponding radar from the moment of detection of the recognizable object, t _рj ^{( i)} = t ⁽ⁱ⁾ + jT ⁽ⁱ⁾ , where t ⁽ⁱ⁾ is the time of the first measurement of the parameters of the detected recognizable object of the i-th radar, T ⁽ⁱ⁾ is the period of the space survey of the i-th radar antenna), based on which ( step 3) a special algorithm is performed estimation coordinates _pj X, Y _pj (a rectangular stationary ICI Birmingham coordinates associated with RLS) recognizable object. Operations 1 and 2, as well as 3 are common to the prototype method and the claimed method.

в азимут φ $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{vj}}$ и расстояние r_vj ⁽ⁱ⁾ до условного надводного объекта, движущегося на заданной высоте Z_v по проекции оцененной траектории (X_pj,Y_pj, Z_v, t_vj ⁽ⁱ⁾) на горизонтальную плоскость (именуемого далее кратко: "условный надводный объект") Индекс v относит параметры к условному надводному объекту. Высота центра радиолокационных отражателей над уровнем моря условного надводного объекта задается и принимается равной Z_v.The values of the estimated coordinates X _pj , Y _pj in the horizontal plane of the recognized object are recalculated (operation 4) for time instants t _vj ⁽ⁱ⁾ , where (t _vj ⁽ⁱ⁾ = t _pj ⁽ⁱ⁾ ), relative to the coordinates of the installation of the i-th radar ( X ₀ ⁽ⁱ⁾ , Y ₀ ⁽ⁱ⁾ , 0) in accordance with the expressions

to azimuth φ $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{vj}}$ and the distance r _vj ⁽ⁱ⁾ to the conditional surface object moving at a given height Z _v according to the projection of the estimated trajectory (X _pj , Y _pj , Z _v , t _vj ⁽ⁱ⁾ ) on the horizontal plane (hereinafter referred to briefly as: “conditional surface object ") Index v relates the parameters to a conditional surface object. The height of the center of the radar reflectors above sea level of the conventional surface object is set and taken equal to Z _v .

- вектор пересчитанных азимутов, расстояний и моментов времени, к которым они относятся для условного надводного объекта, содержащий все пересчитанные азимуты, расстояния и время от момента обнаружения t_pj ⁽ⁱ⁾=t_p1 ⁽ⁱ⁾ до текущего момента t $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pj}}$ = t $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pξ}}$ ,

где

j = ξ - текущий момент измерения, J - максимальное число измерений азимута, расстояния до распознаваемого объекта (оборотов антенны), при котором принимается решение о распознавании объекта.Then they are formed and stored (operation 5):
is the vector of the measured azimuth values, the distance to the recognized object and the measurement time points, containing all measurements from the moment of detection t _pj ⁽ⁱ⁾ = t _p1 ⁽ⁱ⁾ to the current moment t $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pj}}$ = t $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pξ}}$ ,

is the vector of the converted azimuths, distances and times to which they relate to the conditional surface object, containing all the converted azimuths, distances and time from the moment of detection t _pj ⁽ⁱ⁾ = t _p1 ⁽ⁱ⁾ to the current moment t $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pj}}$ = t $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pξ}}$ ,

Where

j = ξ is the current measurement moment, J is the maximum number of azimuth measurements, the distance to a recognized object (antenna revolutions), at which a decision is made to recognize the object.

Thus, with each new revolution j of the i-th radar antenna, the length of the vectors I _p and I _v increases, they are replenished with new elements, while the elements corresponding to the previous measurements are stored in the vectors I _p and I _v .

The vector I _p has the character of an array of measured data (φ $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pj}}$ , r $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pj}}$ , t $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{pj}}$ ) along the entire trajectory of the recognized object, starting from the moment of detection corresponding to j = 1, and including the current measurement moment corresponding to j = ξ. Measurements continue until the moment corresponding to j = J, at which a decision is made to recognize the object.

The vector I _v has the character of an array of elements (φ $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{vj}}$ , r $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{vj}}$ , t $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{vj}}$ ), simulating the measurement of azimuth and distance from two radars to a conditional surface object along the entire trajectory of its movement, starting from the moment corresponding to j = 1, and including the current moment of simulation, corresponding to j = ξ. The simulation of measurements continues until the moment corresponding to j = J, at which a decision is made on the recognition of the object.

Both vectors I _p and I _v have the same structure and length, increasing in connection with the formation of their synchronous movement of recognizable and conditional surface objects. As the implementation of the new review of the space vector I _p and I _v replenished with new elements, the previous entries in the vector I _p and I _v are stored, which ensures the preservation of the vectors I _p, and I _v of all the information on the trajectories of movement to recognize and conditional surface objects .

Ошибки измерения моментов времени принимаются равными нулю.According to operation 6, a vector of random measurement errors ε is formed, whose elements (ε $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{φj}}$ - azimuth measurement errors, ε $\genfrac{}{}{0ex}{}{\text{(i)}}{\text{rj}}$ - measurement errors of the distance of the i-th radar) are selected according to the distribution law and statistical parameters of random measurement errors characteristic of measurements in steps 1 and 2. The vector of random errors ε corresponds to the structure and length of the vectors I _p and I _v

Errors of measurement of time instants are taken equal to zero.

формируются суммы I_p+ε и I_v+ε.
В соответствии с операцией 7 по алгоритму, идентичному алгоритму оценивания координат в операции 3, для каждого j=ξ выполняется многократное (k раз) оценивание по вектору I_p+ε высоты движения распознаваемого объекта и многократное (k раз) для каждого j=ξ оценивание по вектору I_v+ε высоты движения условного надводного объекта.Next, at the end of step 6 for each

the sums of I _p + ε and I _v + ε are formed.
In accordance with step 7, according to an algorithm identical to the coordinate estimation algorithm in step 3, for each j = ξ, multiple (k times) estimation is performed using the vector I _p + ε of the height of the recognized object’s movement and multiple (k times) for each j = ξ according to the vector I _v + ε the height of the movement of the conditional surface object.

For each next kth assessment, all elements of the random error vector ε are updated and take on new values. Since at each kth estimation from the vectors I _p + ε and I _v + ε, which contain information about the entire trajectory, the elements of the vector ε take new random values, this simulates the process of repeated (k times) measurements (from the moment of detection of the recognizable object to the present moment) azimuths and distances to the recognizable and the process of repeated (k times) simulation of measurements (from the moment of detection of the recognizable object to the present moment) azimuth and distance to the conditional objects, i.e. repeated (k times) repeated movement of recognized and conditional surface objects along the initial trajectory from its beginning to the current moment of estimation is simulated. Information on the change of the number k is generated during operation 7 and is taken into account in operation 6 when updating the elements of the vector ε.

где значение величины К ограничивается сверху условием сходимости статистических параметров указанных массивов.At the end of operation 7, for each j = ξ, the {Z _pk } _jth array (dimension K) of random values of the estimated height of movement Z _{pk of the} recognized object and {Z _vk } _jth array (dimension K) are formed of random values estimated height of movement Z _{vk of a} conventional surface object. The dimension of the mentioned arrays is determined by the value

where the value of K is limited from above by the condition for the convergence of the statistical parameters of the indicated arrays.

A conditional surface object, the height of movement of which we have set and, therefore, is known, was introduced to ensure the formation of a model comparison situation when the compared objects (in this case, a recognizable object and a conditional surface object) differ only in the height of movement. The height of movement of the conditional surface object is set by us (known), and the height of movement of the recognized object is unknown. Moreover, other characteristics of the recognized object and the conditional surface object are the same:
- the conditional surface object moves on a projection onto the horizontal plane of the trajectory along which the recognizable object moves, i.e. the trajectories in the horizontal plane of both objects are the same and synchronous;
- the vectors I _p and I _v have the same structure, length and are formed synchronously, while the formation of the elements of the vectors (for a recognizable object - by measurements, for a conditional surface object "by simulating a measurement, i.e. recounting) is relative to the same radar position;
- the same measurement errors are added to the vectors I _p and I _v .

Затем вычисляется оценка степени принадлежности условного надводного объекта к классу воздушных объектов для каждого j=ξ по массиву {Z_vk}_j, которая характеризуется частотой F_vj выпадения значений оцененных высот условного надводного объекта в пространство высот выше среднего значения

массива оцененных высот условного надводного объекта

где суммирование в числителе отношения производится по всем элементам массива Z_vμ, для которых выполняется условие

Для распознаваемого объекта для каждого j=ξ выполняется (операция 9) вычисление гистограммы массива {Z_pk}_j, после чего вычисляется оценка степени принадлежности распознаваемого объекта к классу воздушных объектов для каждого j= ξ по массиву {Z_pk}_j, которая характеризуется частотой F_pj выпадения значений оцененных высот распознаваемого объекта в пространство высот выше среднего значения

массива оцененных высот условного надводного объекта

где суммирование в числителе отношения производится по всем элементам массива Z_pη, для которых выполняется условие

Информация о величине

сформированная в ходе операции 8, учитывается в операции 9 при вычислении F_рj.Next (operation 8) for a conditional surface object for each j = ξ, the histogram [3] of the array {Z _vk } _j is calculated,
as well as its average value

Then, an estimate is calculated of the degree of belonging of the conditional surface object to the class of air objects for each j = ξ in the array {Z _vk } _j , which is characterized by the frequency F _{vj of} falling values of the estimated heights of the conditional surface object in the height space above the average value

array of estimated heights of the conditional surface object

where the summation in the numerator of the ratio is performed over all elements of the array Z _vμ for which the condition

For a recognized object for each j = ξ, the histogram of the {Z _pk } _j array is calculated (step 9), and then an estimate is made of the degree of belonging of the recognized object to the class of air objects for each j = ξ from the array {Z _pk } _j , which is characterized by the frequency F _{pj the} fall of the values of the estimated heights of the recognized object in the space of heights above the average value

array of estimated heights of the conditional surface object

where the summation in the numerator of the ratio is performed over all elements of the array Z _pη for which the condition

Value Information

generated during operation 8, is taken into account in operation 9 when calculating F _pj .

т.е. операция 10 повторяется многократно (J раз), то процесс сравнения и результат формирования соответствующего заключения имеют статистический характер.The above recognition process of distant objects ends with a comparison (operation 10) for each value j = ξ of frequency F _pj with frequency F _vj acting as a threshold value and forming a conclusion about recognition of an air object in a remote object. Because

those. operation 10 is repeated many times (J times), then the comparison process and the result of the formation of the corresponding conclusion are statistical in nature.

If the recognizable object moves at the same height at which the conventional surface object moves, then the frequency values (F _vj and F _pj ) characterizing the degree of belonging of these objects to the class of air objects are close to each other, i.e. F _vj ≈F _pj . If the recognizable object moves above the conditional surface object, then the frequency F _pj characterizing the degree of belonging of the recognizable object to the class of air objects will exceed a threshold value equal to the frequency F _vj characterizing the degree of belonging of the conditional surface object to the class of air objects, and the value J is chosen from the sufficiency condition for the formation of the conclusion F _pj > F _vj . In the latter case, a conclusion is formed on recognition of an air object in a remote object.

 Thus, distant objects are recognized as airborne if the frequency of falling estimates of their height in space is higher than the average value of the array of estimated heights of the conditional surface object, which characterizes the degree of belonging of the recognized object to the class of air objects, exceeds the threshold value equal to the frequency of falling estimates of the height of the conditional surface object in space above the average value of the array of estimated heights of the conditional surface object characterizing the degree of belonging to the class of air The object of the conditioned surface objects.

The claimed method for recognizing airborne objects by marine traffic control systems provides a comparison of the frequencies F _pj and F _vj and respectively obtain one of the results:
- "a recognized object is not airborne" if F _vj ≈F _pj , or F _pj <F _vj
- "a recognizable object is air" if F _pj > F _vj ,
which leads to the property of recognizing remote air objects in an expanded (in comparison with the prototype method) space of the claimed method for recognizing remote air objects by including in the number of recognizable remote air objects the frequency of which the height estimates fall into space is higher than the average value of the array of estimated heights of the conditional surface object , characterizing the degree of belonging of remote air objects to the class of air objects, exceeds the threshold value equal to h The frequency of the loss of estimates of the height of the conditional surface object in space is higher than the average value of the array of estimated heights of the conditional surface object, which characterizes the degree of belonging to the class of air objects of the conditional surface object.

Currently, a device that implements the claimed method is in the stage of numerical simulation and includes:
- two radars are located in a fixed coordinate system at points of the radar station i = 1 with coordinates (-6000, 0, 0), radar station i = 2- (6000, 0, 0);
- radar antennas carry out a circular survey with a viewing period T ⁽ⁱ⁾ = 1 s;
- the recognizable object moves in the YOZ plane at an altitude of 500 m at a speed of 20 m / s (the speed of the recognizable object is close on the one hand to the speed of helicopters when they perform special work, and on the other to the speed of high-speed sea vessels, which excludes reliable identification of the class object (air or surface) in speed) in the direction to the origin from large distances (50 km),
- conditional surface object moves along the projection of the trajectory of the recognized object on the sea surface. The movement height of the center of the radar reflectors of this conditional surface object is taken equal to 30 m above sea level;
- the dimension of the arrays {Z _pk } and {Z _vk } is limited to K 500. A further increase in K (when reevaluated using the same vectors I _v and I _p for a given j) does not change the variance and the average value of the arrays [ Z _pk } _j and {Z _vk } _j , which indicates a sufficient value of the selected value of K and the condition for convergence of the statistical characteristics of the arrays {Z _pk } _j and {Z _vk } _j ;
- multiple assessment of the height of the recognized and conditional surface objects is carried out in exact accordance with the algorithm for estimating the coordinates of the prototype method.

 The simulation results are presented in FIGS. 2-6.

In FIG. Figure 2 shows a typical diagram of the estimated height Z _p (Z _source - true height) of the movement of an air object obtained in step 3. The diagram indicates a lack of a prototype method for recognizing air objects: for large distances of an object from the radar, the error in estimating the height of movement increases, which confirmed by the growth of its standard deviation σ _p with increasing distance from the radar to a recognizable object. This property is equally characteristic of a conditional surface object (Fig. 3), in which the center of radar reflectors is located at a certain height above sea level and, therefore, its height is estimated similarly (Z _v ), as is done for airborne objects. At small distances from objects to the radar, there is a pronounced difference between the values of the estimated heights Z _p and Z _v , which allows you to confidently recognize an air object. With increasing distance from objects to the radar, the charts of estimated heights Z _p and Z _v take comparable values and, starting with the removal of r _s , recognition (separation of Z _p and Z _v ) of an air object by a device that implements the prototype method is excluded.

которого обозначено точкой 13. Совокупность аналогичных средних значений для других j, соединенных между собой, представлено кривой 14. Заштрихованная часть 15 гистограммы (выше среднего значения

представляет собой площадь, нормированная величина которой ко всей площади гистограммы 12 является частотой F_vj, характеризующей степень принадлежности условного надводного объекта к классу воздушных объектов для данного значения j=ξ.
На фиг. 5 представлены результаты оценивания высоты воздушного объекта, истинная высота движения которого представлена прямой 16. В точке, соответствующей расстоянию r_j (для j=ξ), показана гистограмма 17 для массива оцененных высот {Z_pk}_j. Заштрихованная часть 18 гистограммы (выше среднего значения

представляет собой площадь, нормированная величина которой ко всей площади гистограммы 17 является частотой F_pj, характеризующей степень принадлежности распознаваемого удаленного объекта к классу воздушных объектов (для данного значения j=ξ), относительно уровня среднего значения

, массива оцененных высот {Z_vk}_j условного надводного объекта.Figure 4 presents the results of estimating the height of a conditional surface object, the true height of which is represented by a straight line 11. At a point corresponding to the distance r _j (for j = ξ), a histogram 12 of an array of estimated heights {Z _vk } _{j is} shown, the average value

which is indicated by point 13. The set of similar average values for the other j, interconnected, is represented by curve 14. The hatched part 15 of the histogram (above the average value

represents the area, the normalized value of which to the entire area of the histogram 12 is the frequency F _vj , characterizing the degree of belonging of the conditional surface object to the class of air objects for a given value j = ξ.
In FIG. Figure 5 shows the results of estimating the height of an air object, the true height of which is represented by straight line 16. At a point corresponding to the distance r _j (for j = ξ), histogram 17 is shown for the array of estimated heights {Z _pk } _j . The hatched portion of the histogram is 18 (above the average

represents the area, the normalized value of which to the entire area of the histogram 17 is the frequency F _pj characterizing the degree of belonging of the recognized remote object to the class of air objects (for a given value j = ξ), relative to the average value

, an array of estimated heights {Z _vk } _{j of a} conditional surface object.

Figure 6 presents the frequency diagram F _vj obtained by connecting the curve 19 of the values obtained for all values of ξ corresponding to the range of distances r = (5.50) km. Similarly, a diagram 20 is obtained for the frequency F _pj characterizing the degree of belonging of the recognized object to the class of air objects.

From the relation of diagrams 19 and 20 it follows that the condition F _pj > F _vj is fulfilled for r _j <r _d . Confident recognition of a remote air object occurs at r _j ≤r ' _d , which requires a total number of measurements of J≈1100.

From a comparison of the diagrams Z _p and Z _v (Fig. 3) and 19, 20 (Fig. 6), it follows that r ' _d > r _s , i.e., the implementation of the inventive method in comparison with the prototype method allows recognition of air objects at great distances.

 From the above it follows that the task set by the claimed method is realized, consisting in expanding the recognition space of airborne objects (including areas of large distances) and recognizing remote airborne objects.

 Thus, the results obtained indicate the achievement of a technical result from the application of the claimed method for recognizing remote air objects.

Sources of information
1. Patent DE 4123898 A1, July 18, 91. Three-coordinate radar system (ISM 85-08-94, page 8).

 2. Nabaa Nassib, Bishop Robert H. Estimste fusion For 2D search sensors / AIAA Guidance, Navig and Contr. Conf, Baltimore, Md, Aug. 7-10, 1995: Collect. Techn. Pap. Pt 1. - Washington (D. C.), 1995 .-- S. 677-684. (Russian Railways "Automation and Computer Engineering", 1997, 1A-431).

 3. Taylor J. Introduction to the theory of errors. Translated from English, Moscow: Mir, 1985.

Claims (1)

 A method for recognizing distant airborne objects, in which the azimuth and distance to a recognized object are measured by two two-coordinate radar stations, estimated from the measurement data, the coordinates of the recognized object, characterized in that they additionally enter data on the trajectory of the conditional surface object by recalculating the estimated horizontal coordinates of the recognized object in azimuth and distance from each radar station to a conventional surface object moving at a given height according to the project and the trajectories of the recognized object on the horizontal plane, form and store a vector of measurement data from two radar stations about the azimuth and distance to the recognizable object containing all measurements from the moment of detection to the current moment, as well as a vector containing all recalculated data from the moment of detection of the recognized object to the current moment about the azimuth and the distance from two radar stations to the conditional surface object moving at a given height along the projection of the trajectory of the of a known object on a horizontal surface, a vector of random measurement errors is formed, the structure and length of which is consistent with the stored data vectors, the sums of the stored data vectors and the vector of random measurement errors are formed and performed on the basis of multiple calculations, after each new measurement of the coordinates of the recognized object, formation an array of estimated heights of movement of a recognized object, as well as an array of estimated heights of movement of a conditional surface object moving at a given height according to the projection of the estimated trajectory of the recognizable object onto the horizontal plane, after each new measurement of the coordinates of the recognizable object, histograms of arrays of estimated motion heights of the recognizable and conditional surface objects are constructed, the frequency of estimating the height of the recognizable object in the space above the average value of the array of estimated heights of the conditional surface object with a threshold value equal to the frequency of falling estimates of the height of the conditional surface object into space above the average value of the array of estimated heights of the conditional surface object moving at a given height on the projection of the trajectory of the recognizable object onto a horizontal surface and form a conclusion on the recognition of an air object in a remote object in the case when the frequency of falling estimates of the height of the recognizable object in space is higher the average value of the array of estimated heights of the conditional surface object exceeds a threshold value equal to the frequency of falling estimates of the height of the conditional th object in the freeboard space above the mean value array estimated conditional freeboard heights of an object moving at a predetermined height on the projection trajectory recognized object on a horizontal surface.

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