X-band active atmospheric waveguide beyond-visual-range detection system and method

Abstract

The invention provides an X-band active atmospheric waveguide beyond visual range detection system and method. The system comprises a waveguide transmitting antenna, a waveguide receiving antenna, a satellite positioning receiving antenna, a transmitter, a receiver, a data processor, a computer and a power supply system. The transmitter is connected to the waveguide transmitting antenna, the waveguide transmitting antenna is used for transmitting X-band signals, the waveguide receiving antenna is used for receiving shore-based radar signals and echo signals and is connected to the receiver, and the satellite positioning receiving antenna is used for receiving navigation satellite signals and is connected to the receiver. The receiver is connected to the data processor, the data processor is connected to the computer, and the power supply system is respectively connected to the transmitter and the receiver. The method has the beneficial effects that the sea clutter interference resistance is improved; the detection precision is improved; the reliability of the detection capability is improved; the calculation capability is improved; and the calculation complexity is reduced.

Description

Technical Field

[0001] The invention belongs to the field of atmospheric waveguide over-the-horizon detection, and in particular relates to an X-band active atmospheric waveguide over-the-horizon detection system and method. Background Art

[0002] Atmospheric waveguides mainly include evaporation waveguides, surface waveguides (also called ground waveguides), suspended waveguides (also called lift waveguides), etc. Evaporation waveguides are formed due to the large water vapor gradient near the ground layer caused by the evaporation of water vapor from a large area of ​​water. Surface waveguides and suspended waveguide structures are special atmospheric stratifications formed by the combined effect of atmospheric temperature inversion or atmospheric temperature inversion and a sharp decrease in humidity with height.

[0003] The research on atmospheric ducts can be traced back to the 1930s. Due to the development and gradual use of radar technology at that time, the over-the-horizon phenomenon gradually attracted the attention of various countries. Later it was proved that these over-the-horizon phenomena were caused by atmospheric ducts. The detection capability of traditional system design is limited. It can only achieve over-the-horizon detection of offshore evaporation ducts, but cannot effectively achieve over-the-horizon detection for surface ducts and suspended ducts.

[0004] From the perspective of atmospheric duct detection, accurate regionalization and high-time resolution detection cannot be achieved, and the problems of atmospheric duct horizontal inhomogeneity, rapid detection and passive detection cannot be completely solved, which directly affects the effective application of atmospheric ducts. Summary of the invention

[0005] In view of this, the present invention aims to propose an X-band active atmospheric duct over-the-horizon detection system and method to solve the problems of the inability to achieve accurate regionalization and high time resolution detection, the inability to completely solve the problems of atmospheric duct horizontal inhomogeneity, rapid detection and passive detection.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows: In a first aspect, the present invention provides an X-band active atmospheric waveguide over-the-horizon detection system. The invention comprises a waveguide transmitting antenna, a waveguide receiving antenna, a satellite positioning receiving antenna, a transmitter, a receiver, a data processor, a computer and a power supply system, wherein the transmitter is connected to the waveguide transmitting antenna, the waveguide transmitting antenna is used to transmit an X-band signal, the waveguide receiving antenna is used to receive a shore-based radar signal and an echo signal, and the waveguide receiving antenna is connected to the receiver, the satellite positioning receiving antenna is used to receive a navigation satellite signal, and the satellite positioning receiving antenna is connected to the receiver, the receiver is connected to the data processor, the data processor is connected to the computer, the power supply system is connected to the transmitter and the receiver respectively, the receiver is provided with three independent channels, the three independent channels are channel one, channel two and channel three respectively, the channel one is used to receive an echo signal, the channel two is used to receive an intermediate frequency signal, the channel three is used to receive a shore-based radar signal, and the data processor is used to receive signals from channel one, channel two and channel three.

[0007] Furthermore, the transmitter includes a filter module circuit, an amplifier module circuit and an up-conversion module circuit. The main control chip inside the transmitter generates a pulse signal, and the pulse signal is transmitted to the waveguide transmitting antenna after passing through the filter module circuit, the amplifier module circuit and the up-conversion module circuit.

[0008] Furthermore, the receiver also includes a filter module circuit, an amplifier module circuit and a down-conversion module circuit. The satellite positioning receiving antenna actively receives multi-frequency direct signals from GPS, BDS, GLONASS, and GALILEO navigation constellations. The multi-frequency direct signals become intermediate frequency signals after passing through the filter module circuit, the amplifier module circuit and the down-conversion module circuit and are transmitted to channel two of the receiver.

[0009] Furthermore, the receiver also includes an ADC data acquisition module, and the echo signal is transmitted to a data processor after being processed by the ADC data acquisition module.

[0010] Furthermore, the interior of the power supply system is an isolated structure to achieve independent power supply for each unit in the system.

[0011] Furthermore, the computer realizes real-time monitoring of the target signal and completes the issuance of relevant instructions to control the operation and shutdown of the system.

[0012] In a second aspect, based on the same concept, the present invention also provides an X-band active atmospheric waveguide over-the-horizon detection method, comprising the following steps: The X-band active atmospheric waveguide over-the-horizon detection system receives the work instruction from the upper computer of the computer, and the transmitter responds to the work instruction and generates a pulse signal, which is transmitted to the waveguide transmitting antenna after passing through the filter module circuit, the amplifier module circuit, and the up-conversion module circuit; The satellite positioning antenna actively receives the direct signals of GPS, BDS, GLONASS, and GALILEO navigation. The direct signals are filtered, amplified, and down-converted to become intermediate frequency signals. The intermediate frequency signals are transmitted to channel 2 of the receiver, and the navigation messages are obtained after modulation and demodulation. The navigation messages are analyzed to obtain the meteorological parameter profiles. The waveguide receiving antenna receives the echo signal of the object under test, and the echo signal is transmitted to channel 1 of the receiver. Then, the ADC acquisition module completes data acquisition and down-conversion processing, and the processed echo signal is transmitted to the data processor; The waveguide receiving antenna receives the reflected electromagnetic wave signal and infers whether there is a waveguide in the atmosphere and its related parameters by analyzing the signal strength, propagation time and frequency characteristics; The data processor receives the signal of channel 1 and combines it with the atmospheric vertical surface layer correction model to obtain the precise value of the evaporation duct height, which is recorded as Data0. The data processor receives the signal of channel 2, combines it with the satellite observation network of the GNSS system, obtains the satellite elevation and azimuth information data, and determines whether the atmospheric duct exists, then obtains the marine meteorological parameter profile, and stores the processed data, which is recorded as Data1; The data processor receives the signal from channel 3 and performs convolutional neural network learning on the shore-based radar data, which is recorded as Data2; The data processor fuses Data1 and Data2, and corrects the data in real time through the Kalman filter algorithm. Then the convolution layer slides the convolution kernel on the data to perform convolution operations and automatically extracts local features related to atmospheric waveguides in the data, while the pooling layer filters and compresses the features extracted by the convolution layer.

[0013] Furthermore, the establishment condition of the atmospheric vertical surface layer model is a non-neutral layer structure, and the formula of the modified model is: ; In the formula, is a function related to stability, is the friction speed, is the Karman coefficient, is the roughness length, is the height, stability parameter , where L is the Monin-Obukhov length and wind speed physical quantity.

[0014] Compared with the prior art, the X-band active atmospheric waveguide over-the-horizon detection system and method described in the present invention has the following advantages: (1) The X-band active atmospheric duct over-the-horizon detection system and method described in the present invention adopts active detection, giving full play to the regional detection advantages of satellites and air-based detection to achieve accurate detection of atmospheric ducts, improve the ability to resist sea clutter interference, detection accuracy and reliability.

[0015] (2) In the X-band active atmospheric duct over-the-horizon detection system and method described in the present invention, the convolution layer of the data processor performs a convolution operation by sliding the convolution kernel on the data, thereby automatically extracting local features related to the atmospheric duct in the data, and the pooling layer of the data processor screens and compresses the features extracted by the convolution layer, thereby reducing the amount of data and the complexity of calculation while keeping the translation of the features unchanged. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 The signal flow diagram of the overall system according to the embodiment of the present invention; Figure 2 A signal flow diagram of a receiver subsystem according to an embodiment of the present invention; Figure 3 A schematic diagram of a data fusion signal Kalman filtering process according to an embodiment of the present invention; Figure 4 Schematic diagram of the data fusion signal convolution pooling process described in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0018] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0019] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0020] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0021] like Figures 1 to 4 As shown, an X-band active atmospheric waveguide over-the-horizon detection system includes a waveguide transmitting antenna, a waveguide receiving antenna, a satellite positioning receiving antenna, a transmitter, a receiver, a data processor, a computer and a power supply system, wherein the transmitter is connected to the waveguide transmitting antenna, the waveguide transmitting antenna is used to transmit X-band signals, the waveguide receiving antenna is used to receive shore-based radar signals and echo signals, and is connected to the receiver, the satellite positioning receiving antenna is used to receive navigation satellite signals, and is connected to the receiver, the receiver is connected to the data processor, the data processor is connected to the computer, the power supply system is connected to the transmitter and the receiver, respectively, the receiver is provided with three independent channels, namely channel one, channel two and channel three, and channel one is used to receive echo signals , the channel 2 is used to receive navigation satellite signals, the channel 3 is used to receive shore-based radar signals, the data processor receives signals from the receiver channels 1, 2 and 3 in real time, and obtains corresponding data Data0, Data1 and Data2 respectively after processing the signals of the independent channels, the data Data1 is stored in the memory, the data processor fuses the data Data1 and Data2, and corrects the data in real time through the Kalman filter algorithm, so as to obtain information data such as temperature, humidity, atmospheric refraction profile, vertical profile of water vapor pressure and coordinates, the information data enters the convolution layer of the data processor, the convolution layer processes the data and transmits it to the pooling layer of the data processor, the pooling layer processes the data and transmits it to the computer.

[0022] Advantages of the present invention: (1) Active detection is adopted to give full play to the regional detection advantages of satellites and airborne bases to achieve accurate detection of atmospheric waveguides, improve the ability to resist sea clutter interference, detection accuracy and reliability.

[0023] (2) The convolution layer of the data processor performs convolution operations by sliding the convolution kernel on the data, thereby automatically extracting local features related to atmospheric waveguides in the data. The pooling layer of the data processor filters and compresses the features extracted by the convolution layer, thereby reducing the amount of data and the computational complexity while keeping the features unchanged in translation.

[0024] In a preferred embodiment of the present invention, the internal main control chip of the transmitter generates a pulse signal, and the pulse signal is transmitted to the waveguide transmitting antenna after passing through the filter module circuit, the amplifier module circuit and the up-conversion module circuit. The satellite positioning receiving antenna actively receives multi-frequency direct signals from GPS, BDS, GLONASS, and GALILEO navigation constellations. The signal becomes an intermediate frequency signal after passing through the filter module circuit, the amplifier module circuit and the down-conversion module circuit and is transmitted to the second channel of the receiver. The echo signal becomes an intermediate frequency signal after passing through the ADC data acquisition module and is transmitted to the data processor. After receiving the signal from the receiver channel one, the data processor combines the atmospheric vertical surface layer correction model to obtain data Data0, and the Data0 is the precise value of the evaporation waveguide height. After receiving the signal from the receiver channel two, the data processor combines the existing GNSS system satellite observation network to obtain information such as satellite elevation angle and azimuth angle, thereby determining whether the atmospheric waveguide exists, and then obtaining the marine meteorological parameter profile. The Data1 is the data after the above information is processed. After receiving the signal from receiver channel three, the data processor performs convolutional neural network learning on the shore-based radar data, and Data2 is the above-mentioned processed data. The convolution layer of the data processor performs convolution operation by sliding the convolution kernel on the data, thereby automatically extracting local features related to atmospheric waveguides in the data, and the pooling layer of the data processor screens and compresses the features extracted by the convolution layer. The power supply system adopts an isolated design to achieve independent power supply for each unit in the system. The computer realizes real-time monitoring of the target signal and completes the issuance of relevant instructions to control the operation and shutdown of the entire system.

[0025] The present invention also proposes an X-band active atmospheric waveguide over-the-horizon detection method, comprising the following steps: The X-band active atmospheric waveguide over-the-horizon detection system receives work instructions from the computer host. The transmitter in the system generates a pulse signal according to the work instructions and responds quickly. The pulse signal is transmitted to the waveguide transmitting antenna after passing through the filter module circuit, the amplifier module circuit and the up-conversion module circuit.

[0026] The satellite positioning antenna actively receives the direct signal of GPS, BDS, GLONASS, and GALILEO navigation. The signal first enters through filtering and amplification, and then is down-converted into an intermediate frequency signal, which is transmitted to channel 2 of the receiver for modulation and demodulation to obtain the navigation message, which is analyzed to obtain the meteorological parameter profile.

[0027] The waveguide receiving antenna receives the echo signal of the object under test and the shore-based radar signal. Channel 1 of the receiver receives the echo signal and completes data acquisition through the ADC acquisition module. After the data acquisition is completed, the ADC module will down-convert it to the intermediate frequency, and finally transmit the signal to the data processor.

[0028] The data processor receives the signal from receiver channel 1 and combines it with the atmospheric vertical surface layer correction model to obtain the precise value of the evaporation duct height, which is recorded as Data0.

[0029] The establishment condition of the atmospheric vertical surface layer model is a non-neutral layer structure, and the modified model is: ; In the formula, is a function related to stability, is the friction speed, is the Karman coefficient, is the roughness length, is the height, stability parameter , L is the Morning-Obukhov length, wind speed and other physical quantities.

[0030] The data processor receives the signal of receiver channel 2, and combines the existing GNSS system satellite observation network to obtain information such as satellite elevation angle and azimuth angle to determine the existence of atmospheric ducts, and obtain the marine meteorological parameter profile, and stores the processed data as Data1. The principle is to determine whether the satellite is within the line of sight range by the elevation angle information of the received satellite. If the satellite information is received outside the line of sight range, it means that duct propagation has occurred, and then the length of the atmospheric duct can be determined based on the ray geometric relationship between them.

[0031] The data processor receives the signal from receiver channel 3, performs convolutional neural network learning on the shore-based radar data and records it as Data2, and reads the Data1 data stored in channel 2. The principle is that the shore-based radar emits electromagnetic waves, which propagate in the atmosphere. If it encounters an atmospheric waveguide, its propagation trajectory will undergo special changes.

[0032] The waveguide receiving antenna receives the reflected electromagnetic wave signal and analyzes the signal strength, propagation time, frequency and other characteristics to infer whether there is a waveguide in the atmosphere and the relevant parameters of the waveguide.

[0033] The data processor fuses Data1 and Data2, and uses the Kalman filter algorithm to correct the data in real time. At the same time, the convolution layer performs convolution operations by sliding the convolution kernel on the data, automatically extracting local features related to atmospheric waveguides in the input data. The pooling layer filters and compresses the features extracted by the convolution layer, reducing the amount of data and the complexity of calculation, while keeping the translation of the features unchanged, providing support for beyond-visual-range detection and target recognition.

[0034] The invention discloses an X-band active atmospheric waveguide over-the-horizon detection system and method. The radar wave propagates along the curvature of the earth's surface at a limited height by utilizing the super-refractive effect between seawater and atmosphere, and can detect sea surface and low-altitude targets over-the-horizon.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An X-band active atmospheric waveguide over-the-horizon detection system, characterized in that: The invention comprises a waveguide transmitting antenna, a waveguide receiving antenna, a satellite positioning receiving antenna, a transmitter, a receiver, a data processor, a computer and a power supply system, wherein the transmitter is connected to the waveguide transmitting antenna, the waveguide transmitting antenna is used to transmit an X-band signal, the waveguide receiving antenna is used to receive a shore-based radar signal and an echo signal, and the waveguide receiving antenna is connected to the receiver, the satellite positioning receiving antenna is used to receive a navigation satellite signal, and the satellite positioning receiving antenna is connected to the receiver, the receiver is connected to the data processor, the data processor is connected to the computer, the power supply system is connected to the transmitter and the receiver respectively, the receiver is provided with three independent channels, the three independent channels are channel one, channel two and channel three respectively, the channel one is used to receive an echo signal, the channel two is used to receive an intermediate frequency signal, the channel three is used to receive a shore-based radar signal, and the data processor is used to receive signals from channel one, channel two and channel three.

2. The X-band active atmospheric waveguide over-the-horizon detection system according to claim 1, characterized in that: The transmitter includes a filter module circuit, an amplifier module circuit and an up-conversion module circuit. The main control chip inside the transmitter generates a pulse signal, and the pulse signal is transmitted to the waveguide transmitting antenna after passing through the filter module circuit, the amplifier module circuit and the up-conversion module circuit.

3. The X-band active atmospheric waveguide over-the-horizon detection system according to claim 1, characterized in that: The receiver also includes a filter module circuit, an amplifier module circuit and a down-conversion module circuit. The satellite positioning receiving antenna actively receives multi-frequency direct signals from GPS, BDS, GLONASS, and GALILEO navigation constellations. The multi-frequency direct signals become intermediate frequency signals after passing through the filter module circuit, the amplifier module circuit and the down-conversion module circuit and are transmitted to channel 2 of the receiver.

4. The X-band active atmospheric waveguide over-the-horizon detection system according to claim 1, characterized in that: The receiver also includes an ADC data acquisition module, and the echo signal is transmitted to a data processor after being processed by the ADC data acquisition module.

5. The X-band active atmospheric waveguide over-the-horizon detection system according to claim 1, characterized in that: The interior of the power supply system is an isolated structure, which is used to realize independent power supply for each unit in the system.

6. The X-band active atmospheric waveguide over-the-horizon detection system according to claim 1, characterized in that: The computer realizes real-time monitoring of the target signal and completes the issuance of relevant instructions to control the operation and shutdown of the system.

7. An X-band active atmospheric duct over-the-horizon detection method, implemented based on an X-band active atmospheric duct over-the-horizon detection system according to any one of claims 1 to 6, characterized in that: The following steps are involved: The X-band active atmospheric waveguide over-the-horizon detection system receives the work instruction from the upper computer of the computer, and the transmitter responds to the work instruction and generates a pulse signal, which is transmitted to the waveguide transmitting antenna after passing through the filter module circuit, the amplifier module circuit, and the up-conversion module circuit; The satellite positioning antenna actively receives the direct signals of GPS, BDS, GLONASS, and GALILEO navigation. The direct signals are filtered, amplified, and down-converted to become intermediate frequency signals. The intermediate frequency signals are transmitted to channel 2 of the receiver, and the navigation messages are obtained after modulation and demodulation. The navigation messages are analyzed to obtain the meteorological parameter profiles. The waveguide receiving antenna receives the echo signal of the object under test, and the echo signal is transmitted to channel 1 of the receiver. Then, the ADC acquisition module completes data acquisition and down-conversion processing, and the processed echo signal is transmitted to the data processor; The waveguide receiving antenna receives the reflected electromagnetic wave signal and infers whether there is a waveguide in the atmosphere and its related parameters by analyzing the signal strength, propagation time and frequency characteristics; The data processor receives the signal of channel 1 and combines it with the atmospheric vertical surface layer correction model to obtain the precise value of the evaporation duct height, which is recorded as Data0. The data processor receives the signal of channel 2, combines it with the satellite observation network of the GNSS system, obtains the satellite elevation and azimuth information data, and determines whether the atmospheric duct exists, then obtains the marine meteorological parameter profile, and stores the processed data, which is recorded as Data1; The data processor receives the signal from channel 3 and performs convolutional neural network learning on the shore-based radar data, which is recorded as Data2; The data processor fuses Data1 and Data2, and corrects the data in real time through the Kalman filter algorithm. Then the convolution layer slides the convolution kernel on the data to perform convolution operations and automatically extracts local features related to atmospheric waveguides in the data, while the pooling layer filters and compresses the features extracted by the convolution layer.

8. The X-band active atmospheric duct over-the-horizon detection method according to claim 7, characterized in that: The establishment condition of the atmospheric vertical surface layer model is a non-neutral layer structure, and the formula of the modified model is: ； In the formula, is a function related to stability, is the friction speed, is the Karman coefficient, is the roughness length, is the height, stability parameter , where L is the Monin-Obukhov length and wind speed physical quantity.

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