RU2186406C2 - Transmitter of azimuthal marks - Google Patents

Abstract

FIELD: radiolocation, circular scanning. SUBSTANCE: transmitter of azimuthal marks includes divider, panel generating constants of azimuthal resolution, counter, OR gate, intermediate register, decoder of presence of code, comparison element and delay line. Determination of azimuth is carried out by finding center of pulse burst so that azimuthal position of signals at start and finish of burst is fixed. In this case presence of determination of azimuth does not depend on recurrence rate of azimuthal marks. EFFECT: provision for required azimuthal resolution with irregular scanning of antenna without use of complex additional units. 1 dwg

Description

 The invention relates to the field of radar and can be used in all-round visibility systems.

 Known sensor azimuth marks included in the radar set forth in the book "Radio systems". M., Kazarinov Yu.M. 1990, p. 196.

 In it, azimuth marks are issued after converting the voltages that change as the antenna rotates. However, the device does not provide sufficient azimuth resolution.

 A known azimuth mark sensor is described in the aforementioned source on page 414. It consists of a disk rotating synchronously with the antenna with holes through which light from a slit light source passes to a photodetector. The latter converts light into electrical signals. Thus, the number of azimuthal marks depends on the number of holes in the disk, which does not exceed the final discreteness of the location of the marks and causes quantization errors, which also does not provide the necessary resolution in azimuth (for example, 1 min).

 However, when the disk is rotated uniformly using a time interval to code converter that measures the time interval between two marks, the required azimuth resolution is provided and additional marks are generated between signals from the photodetector. But in most cases, the antenna does not rotate uniformly, which violates the reliability of the issuance of additional azimuth marks in the periods between signals from the photodetector without the use of additional complex nodes that cause the accumulation of failures, and therefore the required azimuth resolution is not provided.

 Using the proposed device provides the necessary azimuthal resolution with uneven rotation of the antenna without the use of additional complex nodes.

 This is achieved by introducing a divider, a panel for outputting a constant, counter, OR element, an intermediate register, a code availability decoder, a comparison element and a delay line, while the group of outputs of the time interval to code converter is connected to the group of inputs of the code availability decoder and the first group of divider inputs, the second the group of inputs and the group of outputs of which are respectively connected to the group of outputs of the constant output panel and to the group of inputs of the intermediate register, a separate input of which is connected to the output of the decoder the presence of codes and with the first input of an OR element having a second input connected through a delay line to the output of the comparison element, the first and second group of inputs of which are respectively connected to the group of outputs of the intermediate register and to the group of outputs of the counter having the first and second separate inputs connected respectively with the output of the OR element and with a separate output of the time interval to code converter.

 The following notation is used in the drawing and in the text.

1 - slotted light source;
2 - a rotating disk with holes;
3 - photodetector;
4 - time slot to code converter;
5 - divider;
6 - panel issuing constants;
7 - counter;
8 - element OR;
9 - intermediate register;
10 - code decoder;
11 - element of comparison;
12 - delay line
wherein the slit light source I is optically coupled through the openings through the openings of the rotating disk with the openings 2 to the optical input of the photodetector 3, the output of which is connected to a separate input of the time interval converter into code 4, having a group of outputs connected to the group of inputs of the code 10 decoder and the first the group of inputs of the divider 5, the second group of inputs and the group of outputs of which are respectively connected to the group of outputs of the output panel of the constant 6 and to the group of inputs of the intermediate register 9, a separate input of which is inen with the output of the code 10 decoder and with the first input of the OR element 8 having a second input connected via a delay line 12 to the output of the comparison element 11, the first and second group of inputs of which are respectively connected to the group of outputs of the intermediate register 9 and to the group of outputs of the counter 7 having the first and second separate inputs connected respectively to the output of the OR element 8 and with a separate output of the time interval converter to code 4.

 The operation of the device is as follows.

 A rotating disk with holes 2 rotates synchronously with the radar antenna. As the disk rotates through the holes, light passes from the slit light source 1 to the photodetector 3, which converts light energy into electrical signals and produces azimuthal labels, the number of which depends on the number of holes in the disk 2. The time interval converter in code 4 measures the time interval between the labels from the photodetector 3 and after the end of the count gives the code of this interval in the divider 5.

 The time interval to code converter works similarly to the range converter presented, for example, in the book by Vasin et al. "Radar Reference Book", 1977.

 In the divider 5, the code of the required number of azimuth marks between the signals from the photodetector, which comes from the panel issuing the constant 6, where it is pre-dialed, is divided into the interval code from the converter 4. For example, when the number of holes in the disk is 360, to ensure azimuthal resolution in one minute, the digital value of the code from the panel output should be 60. The quotient from the output of the divider is stored in intermediate register 9.

 Previously, the intermediate register 9 is set to its initial state by a pulse from the code 10 decoder, fixing the presence of the code at the output of the time interval converter 4 after the end of the time count.

 The intermediate register 9 stores the code for the time between the signals from the photodetector 3. Then, the time is counted again in the converter 4. As the counter is counted, the converter gives out clock pulses to counter 7. Counter 7 counts these pulses until the code at the output of counter 7 is equal with the code at the output of the intermediate register 9.

 At the time of the equality of these codes, the comparison element 11 will give an azimuth mark signal, which can be used for further processing.

 At the same time, this signal sets counter 7 through the delay line 12, through the OR element 8. The delay time is equal to the response time of the triggers of counter 7. In addition, at the end of the count, the counter is reset by the pulse from the code 10 decoder.

 When the rotation speed changes, the information stored in the intermediate register 10 changes, but the number of operations of the comparison element 11 does not change, that is, the azimuthal resolution specified on the panel for outputting the constant 6 is stored, namely, each time after the antenna is turned, for example, by an amount equal to one minute , the comparison element 11 produces an azimuthal mark.

 To ensure operation, high-speed integral elements are used, for example, with ESW logic. The reliability of the issuance of azimuthal marks depends on the stability of the transducer 4 and on the change in the speed of rotation of the antenna during the time between storing information in the intermediate register 9 and the moments of operation of the comparison element 11.

 Since this time is a value not exceeding 30 ms, it will not have time to violate the presented accuracy characteristics in azimuth.

 The proposed device can be used in radar all-round visions, including those that determine the azimuth, by determining the center of the pack.

 When measuring the azimuth, the azimuthal position of the signals at the beginning and end of the packet is recorded. Moreover, the accuracy of determining the azimuth does not depend on the repetition rate of azimuth marks. In this regard, the device can be used in air traffic control systems, in navigation and direction finding systems. The absence of complex nodes makes the manufacture of the product cheaper and, therefore, provides an economic effect.

Claims (1)

 The azimuthal mark sensor, consisting of a slit light source, a rotating disk with holes, a photodetector and a time interval to code converter, where a slit light source is optically coupled through the holes of a rotating disk with holes to an optical input of a photodetector, the output of which is connected to the input of a time interval converter into the code, characterized in that the divider is entered, the panel for issuing the azimuthal resolution constant, counter, OR element, intermediate register, code availability decoder, element there is a comparison line and a delay line, while the group of outputs of the time slot to code converter is connected to the group of inputs of the code availability decoder and the first group of inputs of the divider, the second group of inputs and the group of outputs of which are respectively connected to the group of outputs of the panel producing the azimuthal resolution constant and with the group of inputs register, a separate input of which is connected to the output of the code availability decoder and to the first input of an OR element having a second input connected via an delay line to the output of the element and a comparison that produces an azimuthal mark signal for further processing, as well as the first and second groups of inputs of which are respectively connected to the group of outputs of the intermediate register and to the group of outputs of the counter having the first and second separate inputs connected respectively to the output of the OR element and to a separate output time-to-code converter.