RU2096798C1 - Device for processing of radar signals - Google Patents

Abstract

FIELD: radar equipment. SUBSTANCE: device has unit which counts ascension and decrease time of envelope, and unit which subtracts codes which follow one another. Output of envelope analysis unit is connected to input unit which counts ascension and decrease time of envelope. Group output of latter unit is connected to group input of subtraction unit which has group output which is connected to group input of indicator. EFFECT: possibility to measure distance using single-frequency continuous sounding signals and signals of greater rate. 2 dwg

Description

 The invention relates to the field of radar and can be used in search systems for objects.

 A device for processing radar signals [1, p. 260 - 265] In it, using a radar receiver, the electromagnetic energy reflected from the object is converted into electrical signals. Further, these signals are allocated above the level in the amplitude selector. The direction is determined by the maximum envelope of the signals and is displayed on the indicator. However, the device is not able to determine the range if the probing signals are continuous or follow with an increased frequency.

 A device for processing radar signals is known (1, p. 383]. A circular viewing process is carried out by converting reflected electromagnetic energy into electrical signals using a radar receiver. Next, these signals are extracted in amplitude above the noise level in the amplitude selector and fed to the signal envelope analysis unit , which determines by the maximum method the direction that is displayed on the indicator, however, the device is not able to determine the range if the probing signals are single-frequency, continuous They came or follow the increased frequency.

 Using the proposed device, the range is determined if the single-frequency sounding signals are continuous or follow with an increased frequency. This is achieved by introducing a block for counting the rise and fall times of the envelope and a subtracter of successive codes, while the output of the block of the envelope analyzer is connected to the input of the block for counting the rise and fall times of the envelope, the group output of which is connected to the group input of the subtracter of successive codes having group output connected to the group input of the indicator.

 In FIG. 1 and the following notation is used in the text: 1 radar receiver; 2 amplitude selector; 3 envelope analysis unit; 4 block counting the time of rise and fall of the envelope; 5 subtracter of successive codes; 6 indicator.

 In this case, the output of the radar receiver through the amplitude selector 2, the envelope analyzer unit 3 is connected to the input of the unit for counting the rise and fall times of the envelope 4 and to the first input of the indicator 6, the group input of which is connected to the group output of the subtractor of the subsequent codes 5 having a group input connected to the group output of the block counting the rise and fall times of the envelope 4.

 The operation of the device is as follows.

 The radar receiver 1 converts the reflected electromagnetic energy into electrical signals during a circular view and extracts signals whose characteristics correspond to the expected object, such as a moving airplane. Amplitude selector 2 selects the signal in amplitude, which exceeds the amplitude of noise and local objects. The extracted signals are sent to the envelope analysis unit 3, which selects the envelope of the signals and gives signals at the beginning and end of the envelope 4 at the time of its maximum amplitude to the unit for calculating the rise and fall times of the envelope 4. In addition, the signal at the time of the maximum amplitude of the envelope enters the indicator 6 to display the direction.

 In FIG. 2 shows the shape of the envelope. Curve AB characterizes the growth of the envelope, and curve BC its decline. Since the radiation pattern rotates in the circular viewing mode, during the delay time of the signal reflected from the object, it will rotate by a certain angle. Therefore, the shape of the envelope will be expressed not by the DBC curve, but by the ABC curve, and the difference of the segments a b d characterizes the distance to the object irradiated with sounding signals. Therefore, the difference between the decay and rise times of the envelope is range information. If the range were equal to zero, then the shape of the envelope would correspond to the DBC curve (the DE curve is shown by a dashed line). Thus, regardless of the width of the radiation pattern for the same ranges, the value of d will be constant. Therefore, we can conclude that the difference between the decay and rise times of the envelope does not depend on the width of the radiation pattern, but depends only on its rotation speed and on range. The rotation speed of the radiation pattern must be such that the value of d a is greater than zero, so that the condition b> о is satisfied.

 The absolute value between the decay and rise times of the envelope is determined in the subtracter of the successive codes 5, which are sequentially received from the counting block of the rise and fall times of the envelope 4, which determines the temporal mismatch between the two signals, namely, between the beginning of the envelope and its maximum, and then between the maximum and end of the envelope. The operation of block 4 is similar to the operation of the range converter.

From the output of the subtractor of successive codes 5, the difference value, directly proportional to the range, goes to indicator 6 for display. We give an example of a specific implementation. Let the radiation pattern rotate at a speed of 60 rpm. Then, with a width of 1 ^o at the location of the object, the intersection time of the object will be 2.8 ms. Fulfilling the above condition, (b> 0) the maximum detection range should not exceed 200 km. If we consider that there are no interfering objects near the rotating antenna that distort the radiation pattern, then the accuracy of determining the maximum envelope can be 1 min, which ensures accuracy in determining the range of 500 m.

 The device can be used in radars for the purpose of increasing the detection range in the process of searching for airborne objects, including in airborne, ship, mobile and portable vehicles.

Claims (1)

 A device for processing radar signals, consisting of a radar receiver, an amplitude selector, an envelope analysis unit and an indicator, where the output of a radar receiver through an amplitude selector, through an envelope analysis unit, is connected to an indicator input, characterized in that a unit for calculating the rise and fall times of the envelope and a subtractor are introduced of successive codes, while the output of the envelope analysis unit is connected to the input of the unit for counting the rise and fall times of the envelope, the group output of which is connected nen with the group input of the subtracter of successive codes having a group output connected to the group input of the indicator.

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