RU2078350C1 - Automatic device which capture traced trajectory - Google Patents

Abstract

FIELD: radars, devices for secondary processing of radar information from on-board radars which run scanning of observed space. SUBSTANCE: device implement criteria for detection of traced trajectories of target kinds of l/m, where m is number of scanning cycles, l is number of lines in scanned area which contain target. EFFECT: increased functional capabilities. 4 dwg

Description

 The invention is intended for use in radar technology, in particular in the secondary processing of radar information survey radar stations.

 It is intended to make a decision about the existence of a target path when analyzing information obtained over several review cycles (Kuzmin S.Z. Digital processing of radar information. M. Sov. Radio, 1967, p. 255). The algorithms on the basis of which the trajectory auto-capture devices are built is based on the detection criteria l from m (l / m). The trajectory occurs with the appearance of one target mark and is transmitted for tracking when hit in the corresponding gates (communication zones) of the target marks in l viewing periods from m neighboring viewing periods. For example, when applying the 3/4 criterion, the trajectory is transmitted for tracking if there are detections (target marks) in three viewing periods in a row or when three target marks appear in a sliding window in four viewing periods (Kuzmin SZ Digital processing of radar information. M. Sov.radio, 1967, p. 280). Algorithms based on 3/4 criteria can be implemented in the form of computer programs, or in the form of devices (Samsonenko S.V. Digital methods for optimal processing of radar signals. M. Military Publishing House of the USSR Ministry of Defense, 1968, p. 102, Fig. 4.19). The latter device is adopted as a prototype of the invention. The prototype device consists of series-connected delay lines for the period of review and logical elements AND or OR, instead of which summing and threshold devices can be used (Samsonenko S.V.Digital methods for optimal processing of radar signals. M. Military Publishing House of the USSR Ministry of Defense, 1968, p. 106.108 Fig. 4.21). Instead of delay lines, memory elements (triggers) can be used that are connected in series to a shift register (Kuzmin SZ Digital processing of radar information. M. Sov. Radio, 1967, p. 211-212, Fig. 3.18).

 The use of a device synthesized using the l / m criterion makes it possible to detect the target path in a minimum time equal to lT, where T is the viewing time and the maximum time for detecting the target path is mT. Typically, the number l is taken equal to 2-3, and m 3-5, the time period of the survey is 3.5-7 s. Hence, the minimum time for capturing the trajectory of an escorted target lies within 7-21 s, which is quite acceptable when capturing a target at long ranges, and at the same time it is completely unacceptable when detecting a target at short ranges when tracking targets in the front hemisphere.

 The objective of the invention is the creation of devices that reduce the time spent on the capture of the target by airborne radar (radar).

 The task is achieved by the fact that in the device "Automatic capture of the followed trajectory", which implements the criterion l / m, consisting of (m-1) series-connected delay lines for the period of review, the outputs of which are connected to the (m-1) inputs of the first adder, output the adder is connected to the input of the threshold device, the threshold of which is given by the number l, the second adder and (k-1) series-connected delay lines for the line time, where K is the number of lines of the field of view, the outputs of these delay lines are connected to the (K-1) input of the second adder output to connected to the m-th input of the first adder and to the input of the first delay line for the review period, the input of the device is connected to the input of the second adder and the first delay line for the time of the line.

 The reduction in time to capture the trajectory due to the introduction of delay lines for the period of review is due to the fact that modern radar systems use a line-by-line survey of space (L.I. Dudnik and Cheresov Yu.I. Aircraft radar devices. / Edited by L.I. Dudnik. Edition VVIA named after N.E. Zhukovsky, 1986, p. 374, Fig. 12.10).

The beam moves in azimuth, at the boundary of the field of view it is shifted in elevation by Δ _c (Δ _c line spacing). To prevent missed targets should be less than the beam width of the antenna in elevation.

 From here, at long ranges (target detection ranges), the target is detected once per review cycle. As the distance decreases, the power of the signal reflected from the target increases, the probability of detecting the target increases, and it begins to be detected not only on one line, but also on two adjacent lines, and at short ranges, target marks and three adjacent lines may appear during one review period .

 The output of the radar carrier to the radio contact area for the purpose can be carried out depending on tactics both at large and medium and short ranges.

 Using the number of lines on which the target was detected, instead of using the number of surveys during which the target was detected, in the synthesis of a device that implements the l / m criterion, it can drastically reduce the time it takes to capture the target's trajectory at medium and short ranges.

 So when using devices using 3/5 criteria, this time is reduced from 3T to 1T when a target is detected on three lines.

 In FIG. 1 shows a block diagram of an automatic trapping machine capture.

 The machine for capturing the followed trajectory contains the first delay line for the line time L.Z. str-1, the second L.Z. page-2, (K-1) -th LZ.str-3, second adder 4, the first delay line for the review period L.Z.t-5, the second L.Z.t-6, the third L.Z .t-7, (m-1) -th LZ.t-8, first adder 9, threshold device with a threshold of l-10.

 We will describe the operation of the automatic machine for capturing the trajectory using the example of the device that implements criterion 3/5, with the number of lines of the field of view K = 4.

 The action of the proposed device will be considered in three situations that simulate the detection process at large, medium and small distances. In the first situation, target detection is performed in the first, third, and fifth review cycles, respectively, on the second, third, and second lines. In the second situation, target detection is performed on the third line of the first review cycle and on the second, third lines of the third review cycle. In the third situation, detection is performed on the second, third and fourth lines of the first review cycle.

 In FIG. 2,3,4 are time charts illustrating the operation of the proposed device that implements 3/5 criteria in the three above situations.

 In these figures, the position, for example, 24 corresponds to the time interval of the existence of 4 lines of the second review period. "1" at the input indicates the appearance of the mark of the detected target on the corresponding line. Vertical digits 1-9 indicate the outputs of the device blocks corresponding to the numbers. At the output of adder 4, the sum of detections for the first review cycle is formed, and at the output of adder 3, the sum of detections for 5 review cycles.

 In FIG. 2 shows the timing diagrams in the first situation. The target detection signal appears at positions 12, 33, 52 at the input of devices in the form of "1". At the output of devices 1, 2, 3, this signal appears with a delay corresponding to the lifetime of one, two, three lines.

 At the output of adder 4, a sequence of units is formed, which with a delay of 1, 2, 3, 4 review periods appears at the output of blocks 5, 6, 7, 8.

 From the moment the first detection mark appears at the output of the adder 9, a sequence of units is formed, which, after the second transformation into a sequence of "2", which is replaced by "3" at the moment of the appearance of the third measurement, which leads to the triggering of the threshold device.

 The device in the conditions of the second situation (figure 3) at time 32 works similarly to work in the first situation.

 At time 33, the target is detected on an adjacent line, which leads to the appearance of "2" at the output of the adder 4 and 3 at the output of the adder 9.

 When the device is operating in the conditions of the third situation, when detection is performed on three adjacent lines, at the output of the adder 4 and 9, "1", "2", "3" are sequentially formed, leading to the triggering of the threshold device 10, during the existence of one period.

 From the above it is seen that at long ranges, when the detection is carried out in one review cycle, the time to capture the target path corresponds to the time of capture of the target by the prototype. When approaching the target, the signal begins to be detected on adjacent lines, which reduces the time it takes to capture the target at short and medium ranges.

 When a target is detected on 3 lines at short ranges (3 situations), the time to capture the target decreases to the time of one review period.

 It follows that the use of the number of lines instead of using the number of surveys during which the target was detected during the synthesis of devices implementing the l / m criterion can drastically reduce the time it takes to capture the target trajectory at medium and short distances.

 A prototype of the proposed device has passed flight tests.

Claims (1)

 An automatic trajectory capture machine that implements the criterion l / m, where l is the number of target detections, m is the number of review periods, consisting of m 1 series-connected delay lines for the review period, the outputs of which and the input of the first delay line for the review period are connected to m inputs of the first the adder, the output of the adder is connected to the input of a threshold device, the threshold of which is given by the number l, characterized in that the second adder and K 1 are connected in series to the delay lines for the line time, where K is the number of lines of the field of view, the output These delay lines are connected to the (K 1) -th inputs of the second adder, whose output is connected to the input of the first delay line to review period, followed by capture of the machine input path connected to the K-th input of the second adder and the input of the first delay line at a time line.

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