RU2510772C1 - Device of determination of distance to ionosphere - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: device of determination of distance to ionosphere can be used in over-the-horizon radars and for research of a status of an air bed of Earth. The specified result is reached with the help of a synchroniser, a pulse transmitter, an antenna switch, an aerial, a receiver, a clock generator, a decoder, a block of secondary processing, an indicator, a peak selector, a variable line of delay, a block of fixing of a certain duration of a forward part of a signal, an analyser of the smallest range, an adder, a panel of delivery of a code of the delay, connected among themselves definitely.

EFFECT: increase in accuracy of determination of distance without reduction of reliability of detection.

1 dwg

Description

The invention relates to the field of radar and can be used in horizontal radars and to study the state of the air layer of the Earth.

A device for determining the range, including to the ionosphere, which can be included in the radar set forth in the book "Radio Engineering Systems", M .: Higher school, 1990, Yu.M. Kazarinov, p. 195, 228. In it, the antenna can radiate electromagnetic energy vertically and be stationary. The synchronizer issues a command to the pulse transmitter to generate probing pulses, which may have a carrier frequency of the long wavelength range necessary for reflection from the ionosphere, and the pulse duration may be, for example, 500 μs.

The signal from the transmitter, passing through the antenna switch, enters the antenna. The reflected electromagnetic energy again enters the antenna and then through the aforementioned antenna switch passes into the receiver. In the latter, electromagnetic energy is converted into electrical energy and the expected signals are extracted. The height to the ionosphere can be measured in the range converter, which determines the mismatch between the clock pulse and the leading edge of the signal from the receiver, while clock pulses from the clock generator, which is triggered by the clock pulse from the synchronizer and stops transmitting pulses before the next clock pulse arrives at the moment the pulse is issued, can be input to the converter input. from the decoder, fixing the code for the end of the count of clock pulses from the Converter. The latter determines the distance from the antenna along its central axis to the ionosphere. The distance can vary and tracking is carried out using the secondary processing unit, from the group of outputs of which information is sent to the indicator for display. However, the accuracy of determining the distance to the ionosphere is not always sufficient. A device for determining the distance to the ionosphere, which can be part of the horizontal radar, described in patent No. 2073881, by A. Chasovskaya, BI No. 5 of 02.20.1997, It uses the same nodes as in the above analogue. However, the accuracy of determining the range is also not always sufficient. Using the proposed device increases the accuracy of determining the range without reducing the reliability of detection.

This is achieved by introducing a block for determining the duration of the front of the signal, a variable delay line, an analyzer of the shortest range, an adder and a panel for issuing a delay code, while the output of the receiver is connected via an amplitude selector, through a block for fixing a certain duration of the front of the signal with a second input of the range converter, which has group of outputs connected through the analyzer of short range to the first group of inputs of the adder, the second group of inputs of which and the group of outputs respectively but connected to: a group of panels issuing code delay outputs and a group of secondary inputs of the processing unit, and a synchronizer output is connected to the input of the clock generator via a variable delay line.

In figure 1 and in the text the following notation:

1 - pulse transmitter

2 - antenna switch

3 - antenna

4 - synchronizer

5 - receiver

6 - variable delay line

7 - amplitude selector

8 - range converter

9 - block fixation of a certain duration of the front of the signal

10 - clock generator

11 - decoder

12 - shortest range analyzer

13 - adder

14 - panel issuing a delay code

15 - block secondary processing

16 - indicator

wherein the synchronizer 4 is connected via a variable delay line 6 to the first input of the clock generator 10 having a second input and output, respectively connected to the output of the decoder 11 and the first input of the range converter 8 having a group of outputs connected to the group of inputs of the decoder 11 and through the analyzer the shortest range 12 with the first group of inputs of the adder 13 having a second group of inputs and a group of outputs, respectively, connected to the group of outputs of the panel issuing the delay code 14 and through the secondary processing unit 15 with g the indicator inputs 16, in addition, the aforementioned synchronizer 4 output is connected via a pulse transmitter 1 to the input of the antenna switch 2, having a combined second input with a second output and a first output, respectively connected to a combined input and output of the antenna 3 and through the receiver 5, through the amplitude selector 7, through the block fixing a certain duration of the front of the signal 9 with the second input of the range converter 8.

The device operates as follows

The antenna 3 emits electromagnetic energy vertically on the earth's surface and can be placed motionless or move horizontally on a moving medium. The synchronizer 4 issues a command to the pulse transmitter 1 to generate probing pulses, which may have a carrier frequency in the long wavelength range necessary for reflection from the ionosphere. The pulse duration in the transmitter may be, for example, 500 μs. The signal from the transmitter, passing through the antenna switch 2, enters the antenna 3. Thanks to the antenna switch, the passage of the received signals from the antenna 3 to the receiver 5 stops at the moment of passing this signal. In this case, the antenna emits electromagnetic energy and can have a beam width of 30-60 degrees . The electromagnetic energy reflected from the ionosphere again enters the antenna 3 and then through the aforementioned antenna switch 2 it enters the receiver 5, where it is converted into electrical signals, which then through the amplitude selector 7, which selects signals that exceed the ambient level and are characteristic of the ionosphere, enter the fixation unit a certain duration of the front of the signal 9. The latter, after passing through the signal for, for example, 1 ms and isolating it as a signal from the ionosphere, gives a pulse to the converter 8. minute time 1 ms exceeds the duration of the signal reflected from any object in the processed range converter 8, the area closer ionosphere but on uncultivated areas. The zones are processed using a range converter 8, where a pulse arrives 1 ms after the ionosphere is fixed by block 9. At the same time, pulses from a clock generator 10, triggered by a clock from synchronizer 4, delayed by a variable delay line 6, are received at the other input of the converter by 4 ms, corresponding to the minimum expected range to the ionosphere. The Converter 8 calculates the range and its issuance at the moment of arrival of the pulse from block 9. At the same time, for example, 4 ms, the processing of signals from other objects stops. At the end of the count, the converter 8 issues the end count code to the decoder 11, which is triggered and gives a pulse to the clock to stop issuing clock pulses until the next clock pulse arrives through the variable delay line 6.

However, due to the instability of the ionosphere and due to phase displacement of the carrier frequency of the meter band, the range information from the converter 8 will change. Therefore, the most optimal range will be the minimum range when reflecting the maximum amplitude closest to the leading edge of the signal.

The analyzer of the smallest amplitude 12, analyzing the successive information from the transducer 8, determines this smallest range. Further, the delay line can be adjusted 6. The shortest-range analyzer 12 and the block for fixing a certain duration of the front of signal 9 perform the functions of a secondary processing unit, presented, for example, in the book “Radio Engineering Systems”, V. Pestryakov. et al., 1985, p. 219.

An example of the performance of the range converter is presented in the book "Reference book of tasks on radar," Vasin VV, Stepanov BM, M .: 1977, p. 214, Fig.9.7. Thus, the information from the transducer 8 will differ from the actual information, for example, by 3 ms. Therefore, the panel for issuing the delay code 14 can output to the adder 13 a delay code equal to the difference of the aforementioned delay time in the variable delay line 6 and the signal extraction time in block 9. A code from the analyzer 12 is received to another group of inputs of the adder 13, and a code characterizing the updated value range to the ionosphere from the group of outputs of the adder 13, enters the group of inputs of the secondary processing unit 15, where temporarily appearing levels of similar durations of signals from moving space objects are excluded, for example At ranges closer to the ionosphere, but more uncultivated areas. An example of a specific implementation of the secondary processing unit 15 is noted in the aforementioned source. From the group of outputs of the secondary processing unit, the corrected updated information about the distance to the ionosphere is sent to indicator 16 for display.

The proposed device can be used in systems that include horizontal radars. This ensures the determination of the height of the ionosphere in different areas. The device can also be used for research purposes and in a global ground-based navigation system. Thus, the use of the proposed device will improve the performance characteristics of products where reflections from the ionosphere are used.

Claims (1)

A device for determining the distance to the ionosphere, consisting of a synchronizer, a pulse transmitter, an antenna switch, an antenna, a receiver, a clock generator, a decoder, a secondary processing unit and an indicator, where the clock generator has a second input and output, respectively connected to the output of the decoder and the first input of the converter range having a group of outputs connected to a group of inputs of the decoder, in addition, the output of the synchronizer is connected through a pulse transmitter to the input of the antenna switch, I have the first output and the combined second input with the second output, respectively connected to the input of the receiver and the combined input and output of the antenna, and the group of outputs of the secondary processing unit is connected to the group of inputs of the indicator, characterized in that the amplitude selector, a variable delay line, a certain fixation unit are introduced the duration of the front of the signal, the analyzer of the shortest range, the adder, the panel issuing a delay code, while the output of the receiver is connected through an amplitude selector, through a block fixing a certain the duration of the front of the signal with the second input of the range converter having a group of outputs connected via the shortest range analyzer to the first group of inputs of the adder, the second group of inputs of which and the group of outputs are respectively connected to the group of outputs of the delay code issuing panel and to the group of inputs of the secondary processing unit, and the synchronizer output is connected to the first input of the clock through a variable delay line.