RU2421749C1 - Direction finder - Google Patents

Abstract

FIELD: physics. ^ SUBSTANCE: method is realised owing to introduction of a unit of parallel delay lines, a unit for determining two amplitude values equidistant from a maximum, and a subtractor of successive codes, wherein the input of the receiving device with increase in field of vision is connected to the input of the unit for determining two amplitude values equidistant from the maximum, having a group of outputs connected through the subtractor of successive codes with a group of read-only memory inputs, and the group of outputs of the beam rotation sensor is connected through the unit of parallel delay lines to the second group of inputs of the subtractor. ^ EFFECT: high accuracy of measuring angular coordinates. ^ 3 dwg

Description

The invention relates to the field of radar and can be used in search and tracking radars. A device for determining the direction, which is part of the radar, described in patent No. 2161807. It determines the direction, including when the radiation frequency of the probe pulses is increased, using monopulse signal processing. In this case, the number of receiving devices should be at least two. And each receiving device has an increased field of view. Direction can also be determined using a single receiver, using analysis of the maximum envelope of the signals. However, with increased detection range and viewing speed, measurement accuracy decreases.

A device for determining the direction, which is part of the radar set forth by the author in patent No. 2337377, is known. In it, the direction can also be determined using one receiving device with an increased field of view. But unlike the aforementioned, the direction code enters the read-only memory where the selected directions are sewn. In this case, the direction that is closest to the wired direction is selected. Next, the selected direction code goes to the subtracter, and the difference is displayed on the indicator. The device may also include a beam rotation sensor, but with an increased viewing speed, the accuracy of measuring the angular coordinates decreases. Using the proposed device increases the accuracy of measuring angular coordinates. This is achieved by the introduction of a unit for determining two amplitudes equally spaced from the maximum, a subtracter, successive codes, and a block of parallel delay lines.

In this case, the output of the receiving device with an increased field of view is connected to the input of the unit for determining two amplitudes equally spaced from the maximum, having a group of outputs connected through a subtracter of successive codes with a group of inputs of a permanent storage device, and the group of outputs of the beam rotation sensor is connected through a block of parallel delay lines with the second group of inputs of the subtractor.

In figure 1 and in the text the following notation:

1 - receiving device with an increased field of view;

2 - beam rotation sensor;

3 - unit for determining two amplitudes equally spaced from the maximum;

4 - block of parallel delay lines;

5 - a subtracter of successive codes;

6 - subtractor;

7 - read-only memory;

8 - indicator.

In this case, the group of outputs of the permanent storage device 7 is connected to the first group of inputs of the subtractor 6, the group of outputs of which is connected to the group of inputs of the indicator 8, moreover, the output of the receiving device with an increased field of view 1 is connected to the input of the unit for determining two amplitudes equally spaced from the maximum 3, having a group of outputs connected through a subtracter of successive codes 5 to a group of inputs of a permanent storage device 7, and a group of outputs of a beam rotation sensor 2 is connected through a parallel delay lines 4 with the second set of inputs of a subtractor 6.

The operation of the device is as follows.

A receiving device with an increased field of view 1 receives electromagnetic signals reflected from objects in the form of bursts of pulses during the space survey and converts them into electrical signals, which are also distinguished by characteristics corresponding to the expected objects. From the output of the receiving device 1, the field of view of which is twice as large as that of the transmitting beam, for example, the signals following one after the other, including with an increased repetition rate, are sent to the unit for determining two amplitudes equally spaced from the maximum 3. The latter determines the values of the amplitudes of the envelope signals that are at equal intervals from the maximum amplitude. This can be done, for example, in the same way as in the envelope maximum analyzer presented in the book “Radio Engineering Systems” by Yu.M. Kazarinova, 1990, M., p. 383, which can determine the amplitude of the maximum signal and output it in the form code. The difference lies only in the fact that not the maximum amplitude is determined, but two amplitudes equally spaced from it.

From the group of outputs of block 3, the codes characterizing the amplitudes are sent to the subtracter of the successive codes 5, where these codes are subtracted. The difference from the group of outputs of the subtractor will characterize the angular position of the object relative to the central axis of the receiving diagram. In this case, regardless of the magnitude of the amplitudes, their difference will have constant values for the same angular directions. For clarification, we use FIG. 2, where the following designations are shown: 9 - receiving radiation pattern, 11-maximum amplitude, 10, 12 - amplitudes equally spaced from the maximum. The amplitude 12 exceeds the amplitude 10, since during the rotation of the receiving diagram 9 synchronously with the transmitting beam, it will shift by a value proportional to the range, and the amplitude 12 will become closer to the maximum at point F of the diagram, and the amplitude 10 will become further from the maximum. Let us draw two parallel segments AB and CD intersecting the receiving diagram 9. Let the object located in the same direction be removed a certain distance. Then, before deleting the object, the diagram will be characterized by the AFB figure, and after deleting the object, it will be characterized by the CFD figure. However, before and after the removal of the object, the difference in amplitudes 12 and 10 will not change.

From the group of outputs of block 5, the information enters the read-only memory 7, where to each of the groups of differences characterizing the angular position of the object relative to the central axis of the receiving diagram, certain angular values are sewn inside this diagram. Moreover, the number of angular values depends on the resolution in the direction. The selected angular value comes from the group of outputs of the permanent storage device 7 to the first group of inputs of the subtractor 6, the second group of inputs of which receives information about the position of the central axis of the transmitting beam, at the moment of arrival of the maximum amplitude in the receiving device 1 in the packet of reflected signals. This angular information is received from the beam rotation sensor 2 through a block of parallel delay lines. An example of a specific implementation of the beam rotation sensor is presented in the aforementioned book "Radio Engineering Systems" by Yu.M. Kazarinova, M., 1990, p. 414. The value of the code delay in block 4 is equal to the time between two pulses in a packet, in particular, between the maximum pulse and the subsequent pulse entering the subtracter of successive codes 5 plus the time for processing information in the subtractor 5. Since the receiving diagram synchronously rotates with the transmitting beam , then the difference from the group of outputs of the subtractor 6 will characterize the direction to the object, which is displayed on indicator 8.

The execution of the unit for determining two amplitudes equally spaced from the maximum 3 can be carried out as shown in figure 3, where the following notation:

13 - delay line;

14 - element of coincidence;

15 - block fixing the maximum amplitude;

16 - element of coincidence;

17 is an element or,

18 - delay line;

19 is a block conversion of the amplitude in the code.

His work is as follows.

The block of fixing the maximum amplitude 15 as a result of envelope analysis gives a signal of arrival of this amplitude from receiver 1 to coincidence element 16, allowing the signal to pass through it, from this receiver, previously delayed using delay line 18, through element or 17 to the amplitude conversion unit into code 19 , the value of the delay line 18 is equal to a certain number of pulse repetition periods. Block 15 also provides a signal through delay line 13 to coincidence element 14, allowing the signal to pass through it from receiver 1, through element or 17 to the aforementioned block for converting amplitude to code. The values of the delay lines 13 and 18 are selected so that the time mismatch between the first and maximum signals and between the maximum and second signals are equal. The unit for converting the amplitude to the code 19 converts the amplitudes into codes, which are sequentially fed into the subtracter of the successive codes 5.

The device ensures the preservation of the accuracy of determining the direction in the presence of one receiving channel, including at increased ranges and viewing speeds. This makes it possible to use the device to determine the range at increased radiation frequencies of the probe pulses, if the directions of the pulse radiation are known in advance.

Thus, the proposed device increases the performance characteristics of radars.

Claims (1)

A direction determining device, consisting of a receiving device with an increased field of view, read-only memory, beam rotation sensor, subtractor and indicator, where the group of outputs of the permanent storage device is connected to the first group of inputs of the subtractor, the group of outputs of which is connected to the group of indicator inputs, characterized in that a block of parallel delay lines, a block for determining two amplitudes equally spaced from the maximum, and a subtracter of the codes consecutively introduced, the output a receiver with an increased field of view is connected to the input of the unit for determining two amplitudes equally spaced from the maximum, having a group of outputs connected through a subtracter of successive codes to a group of inputs of a permanent storage device, and a group of outputs of a beam rotation sensor is connected through a block of parallel delay lines with the second group of inputs of the subtractor.

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