RU2460084C1 - Apparatus for processing radar signals - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: disclosed apparatus has a receiver with a large field of vision, a transmitting beam rotating sensor, four subtractors, three read-only memory devices, a display, an analyser of amplitude values lying equidistant from the maximum amplitude, connected to each other in a certain manner.

EFFECT: high accuracy of determining range and direction.

1 dwg

Description

The invention relates to the field of radar and can be used in search and tracking radars.

A device for processing radar signals, which is part of the radar set forth by the author in patent No. 2337374, is known. In it, the direction can be determined using a receiving device with an increased field of view. However, the accuracy of determining the direction with increasing viewing speed and the radiation frequency of the probe pulses decreases and range determination is not provided. A device for determining the direction, which can also be represented as a device for processing radar signals, is described in patent No. 2421749 (author A. Chasovskaya). It increases the accuracy of determining the direction with an increased radiation frequency of the probe pulses.

The principle of its work is as follows.

A receiving device with an increased field of view receives electromagnetic signals reflected from objects and converts them into electrical signals, which are further distinguished according to the expected characteristics. Further, the signals are distinguished by two amplitudes equally spaced from the maximum. Amplitudes are converted into codes and subtracted when following each other. The difference will characterize the angular position of the object relative to the Central axis of the antenna of the receiving device, as well as the range. In this case, the receiving antenna is rigidly connected with the transmitting one.

This difference then goes to the permanent storage device, where for each group of values certain angular and range values are sewn up, the number of which depends on the resolution in the direction.

The selected angular values come from the group of outputs of the permanent storage device to the first group of inputs of the subtracter, the second group of inputs of which receives information about the central axis of the transmitting beam at the moment of arrival of the maximum amplitude in the receiving device.

This information comes from the transmitting beam rotation sensor and is delayed for a time between the arrival of the second and maximum amplitudes.

The difference from the group of outputs of the subtractor will characterize the direction to the object. It is displayed on the indicator, where range can also be displayed. However, the accuracy of determining the coordinates does not always satisfy the requirements, including due to the distortion of the amplitudes of the signals and the values of the rotation angles, including due to the distortion of the amplitudes of the signals and the values of the rotation angles when passing through the delay lines. In addition, the accuracy of determining the direction depends on the resolution in the direction, which reduces the accuracy characteristics in range. Using the proposed device increases the accuracy of determining the range and direction. This is achieved by introducing an amplitude analyzer equally spaced from the maximum, three subtractors and two read-only memory devices, while the output of the receiving device with an increased field of view is connected to the input of the amplitude analyzer equally spaced from the maximum, having the first, second and third groups of outputs, respectively connected to the first the group of inputs of the third subtractor, with the second group of inputs of the third subtractor, the second group of inputs of the first read-only memory device and the group of inputs of the second post a storage device, the first group of inputs of the first read-only memory connected to the group of outputs of the third subtracter, and the group of outputs of the second read-only memory connected to the second group of inputs of the fourth subtractor, the first group of inputs of which and the group of outputs are respectively connected to the group of outputs of the transmitting beam rotation sensor and with the first groups of inputs of the first and second subtracters, the group of outputs and the second group of inputs of the latter are respectively connected to Ora group indicator inputs and via a third constant storage device with outputs of the first subtractor group.

In figure 1 and in the text the following notation:

1 - receiving device with an increased field of view,

2 - sensor rotation of the transmitting beam,

3 - analyzer of amplitudes equally spaced from the maximum,

4, 5, 6, 7 - subtractors,

8, 9 - read-only memory,

10 - indicator

11 - read-only memory device,

wherein the group of outputs of the subtractor 4 is connected to the first group of inputs of the subtractor 7, which has a second group of inputs and a group of outputs, respectively connected to the group of outputs of the permanent memorizing device 8, with the first group of inputs of the indicator 10 and, via the read-only memory 9, with the second group of inputs of the subtractor 6 having a first group of inputs connected to a group of outputs of a subtractor 4 having a first group of inputs connected to a group of outputs of a rotation sensor of a transmitting beam 2 and having a second group of inputs, connected through a permanent storage device 11 with a third group of outputs of the amplitude analyzer equally spaced from the maximum 3 and a second group of inputs of a permanent storage device 8, the first group of inputs of which are connected to the group of outputs of the subtractor 5, the first and second groups of inputs of which are respectively connected to the first and second the group of outputs of the analyzer 3 having an input connected to the output of the receiving device with an increased field of view 1.

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, signals following one after the other, including with an increased repetition rate, are fed to an amplitude analyzer equally spaced from the maximum 3. The last method logic processing determines the value of the amplitudes of the envelope signals at equal intervals from the maximum amplitude, moreover, there can be several amplitudes, and in the form of codes it outputs from the first and second groups of outputs, respectively, to the first and the second group of inputs of the subtractor 5, where these codes are subtracted and the difference from the group of outputs of the subtractor 5, which characterizes the angular position of the object relative to the central axis and the distance, goes to the first group of inputs of the permanent storage device 8. The analyzer 3 also provides a code from the third group of outputs characterizing half the envelope duration, to the second group of inputs of the read-only memory device 8 and to the group of inputs to the read-only memory device 11. Moreover, as shown in the above Patent ohm regardless of the magnitude of the amplitudes of difference will have a constant value.

It should be noted that the longer the envelope, the greater the interval between the amplitudes coming from the analyzer 3, which determines one or another interval. The amplitudes and duration of the envelope can be determined by analyzing the envelope as shown in the book "Radio Engineering Systems" (Yu.M. Kazarinov, 1990, p. 383). In the read-only memory 8, to each of the groups of differences and the envelope duration, certain angular values are sutured relative to the central axis of the diagram and certain range values, the number of angular values depending on the resolution in the direction.

The selected angular value arrives from the group of outputs of the permanent storage device 8 to the first group of inputs of the subtractor 7, the second group of inputs of which receives information about the position of the central axis of the transmitting beam at the time the maximum amplitude in the packet of reflected signals arrives at the receiver. This information comes from the group of outputs of the subtractor 4, the first group of inputs of which is connected to the group of outputs of the rotation sensor of the transmitting beam 2, and the second group of inputs with the group of outputs of the permanent storage device 11, where depending on the code of the duration of the envelope received by the group of its inputs from the third group of outputs of the analyzer 3, a certain number of angular values, for example five, are filed during the time between the maximum and second amplitudes. From the difference from the subtractor 4, the code from the read-only memory 8 is deducted, which enters the second group of the input of the subtractor 7. Thus, the code from the group of outputs of the subtractor 4 characterizes the current angular values at the moment the maximum envelope arrives at receiver 1 and at the moment the second amplitude code arrives at subtractor 5. Information from the sensor 2 may have a second resolution at a strictly constant speed of rotation of the antenna.

An example of the execution of the beam rotation sensor is presented in the book of Yu.M. Kazarinov "Radio Engineering Systems", p. 414.

Information from the group of outputs of the subtractor 7 also characterizes the direction to the object, which is displayed on the indicator 10, where an in-depth range with continuous radiation can also be displayed. The difference from the group of outputs of the subtractor 7 goes to the group of inputs of the permanent storage device 9, where with an increased frequency of radiation of the probe pulses for each group of differences, the corresponding directions of radiation are sewn. The selected direction enters the subtractor 6, where it is subtracted from the current direction coming from the subtractor 4, and the difference representing the value of the specified range is displayed on indicator 10.

An example of the performance of the analyzer of amplitudes equally spaced from the maximum is shown in figure 2, where the following notation is accepted:

12 - block determining the maximum envelope,

13 is a block of elements of matches,

14 - subtractor,

15 - read-only memory device

16 - block counting the duration of the envelope,

17 - random access memory,

18 - adder

19 is a block conversion of the amplitude of the envelope in the code,

20 is a block comparison codes

21 - block matching elements,

22 is a block of matching elements.

The operation of the analyzer 3 is as follows. The unit for determining the maximum amplitude 12, analyzing the presence of a decrease in the amplitudes of the signals, produces a signal some time after the arrival of the maximum signal, allowing the block of coincidence elements 13 to pass the codes from the unit for counting the envelope 16 to the subtractor 14 and to the read-only memory 15. In the subtractor from this The code from the device 15 is subtracted from the code, the value of which is selected depending on the code from block 13, that is, from the code characterizing half the envelope duration. For example, five codes can be sewn up. The longer the envelope, the greater the removal of amplitudes from the maximum amplitude. This increases accuracy characteristics. Codes of varying envelope amplitudes arrive at random access memory from the envelope amplitude conversion unit to code 19. The signals envelope enters the inputs of the aforementioned blocks 12, 16, and 19 from receiver 1. Counting is performed upon receipt of pulses from the receiver by the number of these pulses, and upon receipt of continuous signal - by the number of clock pulses. The selection of the first amplitude is as follows. The code from block 16 goes to the address group of RAM inputs 17. At this address, the corresponding envelope amplitude code is written from block 19, which is then read after the code is received at the second address group of RAM inputs 17 from the aforementioned subtractor 14. Read code value the first amplitude enters the subtractor 5, the second input of which receives the code of the second amplitude. It is formed after fixing the maximum envelope. In this case, from the second group of outputs of the permanent storage device 15, in which five codes can be sewn up, the selected code enters the adder 18. The value of this code is selected in the permanent storage device 15 so that after addition to the code at the time of fixing the maximum envelope from the block matching elements 13, the sum at the output of the adder 18 expressed the location of the second amplitude, spaced from the maximum amplitude, by the same amount as the first. This amount is stored in the code comparison unit 20, and when the code equal to it is fixed from block 16, it gives an impulse to pass the second amplitude code from block 19 through the block of coincidence elements 21 to the subtractor 5. The code comparison unit 20 also gives permission to the block of coincidence elements 22 to the passage of the filled amount from block 18 to read-only memory devices 8 and 11. Block 20 operates similarly to random-access memory, where the address from the adder 18 is simultaneously stored and at the time of reading gives a pulse to block 21.

An example of a specific implementation of the envelope amplitude determination unit is presented in the book “Functional devices on microcircuits” by V.Z.Nayderova, 1985, Moscow: Radio communication, p. 156.

An example of a specific implementation of the block for calculating the duration of the envelope and the block for determining its maximum is presented in the book "Radio Engineering Systems" by Yu.M. Kazarinova, M .: Higher School, 1990, p. 383.

The proposed device can be used in radars all-round visibility.

This creates the opportunity to reduce the viewing time in the process of improving the accuracy characteristics with pulsed radiation with an increased repetition rate and with continuous single-frequency unmodulated radiation. The accuracy of determining the direction also increases with an accelerated survey when using probe pulses with a normal, underestimated repetition rate, which, if there is only one receiving antenna, provides improved performance characteristics.

Claims (1)

A device for processing radar signals, consisting of a receiving device with an increased field of view, a rotation sensor of a transmitting beam, a subtracter, a permanent storage device and an indicator, where the group of outputs of a permanent storage device is connected to a group of inputs of a subtractor having a group of outputs connected to a group of indicator inputs, characterized by introducing an analyzer of amplitudes equally spaced from the maximum, three subtractors and two read-only memory devices, while the receiving device with an increased field of view it is connected to the input of an amplitude analyzer equally spaced from the maximum, having first, second and third groups of outputs, respectively connected to the first group of inputs of the third subtractor, the second group of inputs of the third subtractor, the second group of inputs of the first read-only memory and the group of inputs of the second read-only memory, and the first group of inputs of the first read-only memory is connected to the group of outputs of the third subtractor, and the group of outputs the second read-only memory is connected to the second group of inputs of the fourth subtractor, the first group of inputs of which and the group of outputs are respectively connected to the group of outputs of the rotation sensor of the transmitting beam and to the first groups of inputs of the first and second subtracters, the group of outputs and the second group of inputs of the latter are respectively connected to the second group indicator inputs and through a third read-only memory - with a group of outputs of the first subtractor.

Images