CN104678385A - High-frequency over-the-horizon radar station selection auxiliary system and method - Google Patents

Abstract

The invention discloses an auxiliary system and method for high-frequency over-the-horizon radar station selection. The auxiliary system includes an antenna, a transceiver switch, a transmitting module, a receiving module, a signal processing and transmission module, and a display and control module. The method utilizes the high-frequency over-the-horizon The radar station selection auxiliary system simulates the working mode of the radar to comprehensively test the environmental conditions of the radar station location, analyze the influence of environmental factors on the radar work by detecting the echo, and finally select the appropriate station location according to the measurement results; The invention provides a light, portable, and low-power high-frequency radar station selection auxiliary system. By simulating the actual radar working mode and combining the on-site electromagnetic environment for evaluation, the station selection is more scientific and effective, and the efficiency of station selection is improved. Success rate.

Description

A high-frequency over-the-horizon radar station selection assistance system and method

technical field

The invention belongs to the field of high-frequency over-the-horizon radar, and in particular relates to a station selection auxiliary system and method for high-frequency over-the-horizon radar.

Background technique

High-frequency over-the-horizon radar usually works in the 3-30MH high-frequency band. With the help of sky wave or ground wave propagation mode, it can realize the remote sensing of dynamic parameters such as wind, wave, and current on the sea surface in a large range, and the effective detection of targets such as ships and low-altitude aircraft. In the detection of sea surface targets, the cost of high-frequency over-the-horizon radar is much lower than that of spaceborne radar systems; It has the advantages of large range, all-weather, and good real-time performance, so it has been widely used in many coastal countries.

High-frequency over-the-horizon radar stations are generally built along the coast. It is necessary to build computer rooms, erect antennas, and lay cables on the seashore. According to functional requirements and relevant regulations on site selection and construction of high-frequency over-the-horizon radar stations, the difficulty of erecting antennas needs to be considered before building the station. , the influence of different positions on the performance of the antenna and the influence of the surrounding working environment, etc. Therefore, before setting up the radar station, it is necessary to do a good job of measurement and evaluation, and evaluate whether the electromagnetic environment of the site and the terrain characteristics of the site are suitable for the construction of the radar station and the radar station. Whether the expected detection effect can be achieved, etc., provide guarantee for the normal operation of the radar after the station is built. In addition, the signals in the working frequency band of high-frequency over-the-horizon radar are very crowded, and the surrounding electromagnetic environment must be monitored before the station is built. However, at present, there are many technologies and researches on monitoring the electromagnetic environment test system of high-frequency over-the-horizon radar at home and abroad. The research on the station selection technology of over-the-horizon radar is still blank. However, it is unable to monitor the quality of radar echoes and the spectral characteristics of interference. At present, most station selections rely on field surveys and on-site observations by relevant professional and technical personnel, and use experience evaluation to select sites and build stations. This will consume a lot of manpower and material resources, and what is more serious is that there is no auxiliary equipment for monitoring In the process of building a high-frequency over-the-horizon radar network, there have been many examples of station selection failures, resulting in a lot of waste and loss of manpower, material and financial resources. Therefore, the rationality of station selection has a great influence on the detection performance of ground wave radar, and designing a light and practical auxiliary system for station selection and giving a method for ground wave radar station selection based on this system will provide a high-frequency over-the-horizon radar The selection station provides great help and support.

Contents of the invention

In order to solve the above technical problems, the present invention provides a high-frequency over-the-horizon radar station selection assistance system and method.

The technical solution adopted by the system of the present invention is: a high-frequency over-the-horizon radar station selection auxiliary system, which is characterized in that it includes an antenna, a transceiver switch, a transmitting module, a receiving module, a signal processing and transmission module, and a display and control module. The antenna is connected to the transceiver switch, the other two ends of the transceiver switch are respectively connected to the output terminal of the transmitting module and the input terminal of the receiving module, the input terminal of the transmitting module is connected to the signal processing and transmission module, and the output terminal of the receiving module is connected to the signal processing and The transmission module is connected, and the display and control module is connected with the signal processing and transmission module; the antenna is a common antenna for sending and receiving, and is controlled by the sending and receiving switch to be in the transmitting or receiving state; the receiving module is used to The signal received by the antenna is pre-processed and digitally processed; the signal processing and transmission module includes a signal processing circuit and a data transmission circuit, which are used for mixing, extracting, filtering and uploading to the digitally processed signal of the receiving module A display and control module; the display and control module is mainly used for mode control and data processing of the auxiliary system; the mode control includes two modes: spectrum monitoring mode and transceiver simulation mode.

Preferably, the transmitting module includes a signal synthesis circuit and a power amplification circuit, and the output end of the signal synthesis circuit is connected to the input end of the power amplification circuit.

Preferably, the signal synthesis circuit is realized by an FPGA-based DDS module and a DAC digital-to-analog conversion circuit.

Preferably, the output signal power of the power amplifying circuit is about 1W, and transmission can be realized without a high-power transmitter.

Preferably, the receiving module includes a bandpass filter circuit, an amplifier circuit and an ADC sampling circuit, the output terminal of the bandpass filter circuit is connected to the input terminal of the amplifier circuit, and the output terminal of the amplifier circuit is connected to the input terminal of the ADC sampling circuit end connected.

Preferably, the signal processing and transmission module mainly includes FPGA-based digital down-conversion, extraction and filtering modules, and the data transmission adopts USB interface or network interface.

Preferably, the display and control module is a mobile terminal such as a notebook computer or a mobile phone.

The technical scheme adopted by the method of the present invention is: a method for selecting a station for a high-frequency over-the-horizon radar, using the described working mode of the high-frequency over-the-horizon radar station selection auxiliary system to simulate the radar to comprehensively test the environmental conditions of the radar station site selection , analyzing the impact of environmental factors on the radar work by detecting echoes, and finally selecting a suitable location for building a station according to the measurement results; it is characterized in that it includes the following steps:

Step 1: Utilize the transceiving simulation mode of the high-frequency over-the-horizon radar station selection auxiliary system to simulate the working mode of the radar, and evaluate the echo quality of the proposed site location in the determined site area; its specific implementation process It is to use the high-frequency over-the-horizon radar station selection auxiliary system to simulate the working state of the high-frequency over-the-horizon radar in this frequency band, transmit the waveform of the same system, and evaluate the echo distance-Doppler spectrum received by it. Comparative analysis determines that the place with relatively high echo quality is the place where the station can be built, and provides a quantitative basis for the site selection of high-frequency over-the-horizon radar stations;

Step 2: Utilize the spectrum monitoring mode of the high-frequency over-the-horizon radar station selection auxiliary system to detect the electromagnetic environment at the proposed site; at this time, the high-frequency over-the-horizon radar station selection auxiliary system does not launch, but only receives echoes; according to Spectrum detection mode receives environmental noise and interference signals, through spectrum analysis, makes statistics on noise and interference data, and gives a spectrum distribution map, which provides a basis for the high-frequency over-the-horizon radar to select a working frequency with relatively small noise and interference;

Step 3: Combining the results of the first two steps and comprehensively evaluating other environmental factors, determine a suitable site for site construction.

Preferably, other environmental factors mentioned in step 3 include natural environment (including marine geographic environment), electromagnetic environment and water source, power supply, transportation and communication.

Compared with the existing high-frequency over-the-horizon radar station selection method, the present invention has the following advantages:

1. By simulating the actual radar working mode and evaluating it in combination with the on-site electromagnetic environment, the site selection is more scientific and effective, and the success rate of station selection is improved;

2. Provide a light, portable, low-power high-frequency radar station selection auxiliary system. The system adopts all-digital transmission and reception technology, which has scalability and versatility. By replacing the antenna, the system can also be used for Site selection for VHF over-the-horizon radar;

3. Make full use of auxiliary equipment to reduce the complexity of ground wave radar station construction;

4. It adopts low power consumption and portable design method, adopts battery power supply, and can work in spectrum monitoring mode and transceiver simulation mode.

Description of drawings

Fig. 1: is the overall system structural block diagram of the embodiment of the present invention.

Fig. 2: It is a structural block diagram of the transmitting module of the embodiment of the present invention.

Fig. 3: It is a structural block diagram of the receiving module of the embodiment of the present invention.

Fig. 4: is a structural block diagram of the signal processing and transmission module of the embodiment of the present invention.

Fig. 5: is a flow chart of the method of the embodiment of the present invention.

Detailed ways

In order to facilitate those of ordinary skill in the art to understand and implement the present invention, the present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the implementation examples described here are only used to illustrate and explain the present invention, and are not intended to limit this invention.

Referring to Fig. 1, it is a system structure block diagram of the high-frequency over-the-horizon radar station selection auxiliary system of the embodiment of the present invention, and the auxiliary system adopts a fully digital design mode. It includes an antenna, a transceiver switch, a transmitting module, a receiving module, a signal processing and transmission module, and a display and control module. The input terminal of the module is connected to the signal processing and transmission module, the output terminal of the receiving module is connected to the signal processing and transmission module, and the display control module is connected to the signal processing and transmission module; the system adopts low power consumption design and is powered by batteries.

The antenna is a common antenna for sending and receiving, and the sending and receiving switch is used to control whether it is in the transmitting or receiving state; when the auxiliary system needs to transmit signals, the sending and receiving switch makes the transmitting module and the antenna conduct, and the system is in the transmitting state. When the system needs to receive signals, the transceiver switch makes the receiving module and the antenna conduct, the system is in the receiving state, and receives echoes or environmental noises. The switching of the transceiver switch is controlled by the synchronous control pulse generated by the signal processing and transmission module.

The receiving module is used to pre-process and digitize the signal received through the antenna; the signal processing and transmission module includes a signal processing circuit and a data transmission circuit, which are used to mix, extract, filter and Upload to the display and control module; the display and control module is mainly used for mode control and data processing of the auxiliary system; mode control includes two modes: spectrum monitoring mode and transceiver simulation mode.

Referring to FIG. 2 , it is a structural block diagram of a transmitting module according to an embodiment of the present invention. The transmitting module includes a signal synthesis circuit and a power amplifier circuit, the output terminal of the signal synthesis circuit is connected with the input terminal of the power amplifier circuit; the signal synthesis circuit can be implemented by a DDS chip, or by an FPGA+DAC chip. In this embodiment, the signal synthesis circuit is realized by an FPGA-based DDS module and a DAC digital-to-analog conversion circuit. According to the transmission timing parameters, transmission waveform parameters and synchronous control pulse, the FPGA synthesizes a certain timing signal by the DDS module, and then converts it into an analog waveform by the DAC chip, and sends it to the transmitting antenna after power amplification. The output signal power is about 1W, and does not require a large The power transmitter can realize the transmission. The DAC chip of this embodiment uses 14-bit chip AD9746; the power amplifier circuit adopts adjustable gain amplification.

Referring to FIG. 3 , it is a structural block diagram of a receiving module according to an embodiment of the present invention. The receiving module completes the preprocessing and digital processing of the signal received by the antenna, and is mainly composed of a band-pass filter circuit, a preamplifier circuit and an ADC sampling circuit. The output end of the band-pass filter circuit is connected to the input end of the amplifier circuit to The output end of the circuit is connected with the input end of the ADC sampling circuit. You can also choose an ADC chip with its own amplification function, so the preamplifier circuit can be used. In this embodiment, the AFE5805 chip is selected. The chip is equipped with a programmable gain amplifier PGA and a sequential linear phase low-pass filter LPF. It adopts radio frequency direct sampling, and the frequency can be set to 60MHz.

Referring to FIG. 4 , it is a structural block diagram of a signal processing and transmission module according to an embodiment of the present invention. The signal processing and transmission module mainly completes the digital down-conversion of the sampling signal and outputs the I/Q baseband data. This part is realized by the digital down-conversion, extraction and filtering modules based on FPGA. The data latched by the AD data is divided into two channels, and the FPGA generates two mutually orthogonal local oscillator signals by the numerically controlled oscillator NCO to mix with them, and the mixed data are intercepted and input to the integral cascaded comb filter CIC respectively. The extracted and filtered data is input to the FIR filter, the shaped and filtered data is stored in the FIFO, and finally uploaded to the display and control terminal through the data transmission interface, and the data transmission adopts the USB interface or the network port. The data transmission of this embodiment adopts USB2.0 interface, and FPGA selects Altera Cyclone IV EP4CE115 FPGA chip, and NCO, mixer, CIC and FIR are all completed by the IP core that Altera company provides.

The display and control module mainly completes the mode control and data processing of the auxiliary system. Mode control includes two modes: spectrum monitoring mode and transceiver simulation mode. In the spectrum monitoring mode, the user sets the spectrum range to be monitored. This range cannot exceed the receiving bandwidth of the antenna. The system will monitor the environmental noise in this frequency band and give a spectrum diagram. In this mode, the antenna does not transmit but only receives, and the display and control terminal obtains a real-time environmental spectrum map by performing fast Fourier transform (FFT) on the received data. In the transceiver simulation mode, the waveform system is linear frequency sweep interrupted continuous wave (FMICW), and the transmit power is about 1W. The user sets parameters such as operating frequency, bandwidth, and frequency sweep cycle. The transmitter synthesizes the transmit waveform according to these parameters and transmits. The control terminal obtains the range-Doppler spectrum of the echo signal by performing two FFTs on the received data.

Referring to Fig. 5, it is the flow process of the method of the present invention, and this method comprises the following steps:

Step 1: Use the transceiver simulation mode of the high-frequency over-the-horizon radar station selection auxiliary system to simulate the working mode of the radar, and evaluate the echo quality of the proposed site; the specific implementation process is to use the high-frequency over-the-horizon radar station selection auxiliary system to simulate the high-frequency over-the-horizon radar In the working state of the line-of-sight radar in this frequency band, the waveform of the same system is transmitted, and the received echo distance-Doppler spectrum is evaluated. Through comparative analysis, it is determined that the place with relatively high echo quality is the place where the station can be built. Provide quantitative basis for site selection of high-frequency over-the-horizon radar stations;

Step 2: Use the spectrum monitoring mode of the high-frequency over-the-horizon radar station selection auxiliary system to detect the electromagnetic environment of the proposed site; at this time, the high-frequency over-the-horizon radar station selection auxiliary system does not transmit, but only receives echoes; according to the spectrum detection mode received Environmental noise and interference signals, through spectrum analysis, the noise and interference data are counted, providing a basis for the high-frequency over-the-horizon radar to select a working frequency with relatively small noise and interference;

Step 3: Combining the results of the previous two steps and comprehensively assessing natural environment data (including marine geographic environment), electromagnetic environment and other environmental factors such as water source, power supply, transportation, communication, etc., determine the appropriate site for site construction.

It should be understood that the parts not described in detail in this specification belong to the prior art.

It should be understood that the above-mentioned descriptions for the preferred embodiments are relatively detailed, and should not therefore be considered as limiting the scope of the patent protection of the present invention. Within the scope of protection, replacements or modifications can also be made, all of which fall within the protection scope of the present invention, and the scope of protection of the present invention should be based on the appended claims.

Claims (9)

1. A high-frequency over-the-horizon radar station selection auxiliary system is characterized in that: comprise antenna, transceiver switch, transmitting module, receiving module, signal processing and transmission module, display and control module, described antenna links to each other with transceiver switch, and transceiver switch The other two ends of the transmission module are respectively connected to the output terminal of the transmitting module and the input terminal of the receiving module. The input terminal of the transmitting module is connected to the signal processing and transmission module. The output terminal of the receiving module is connected to the signal processing and transmission module. The processing and transmission modules are connected; the antenna is a common antenna for sending and receiving, and is controlled by the sending and receiving switch to be in the transmitting or receiving state; the receiving module is used to preprocess the signal received through the antenna and digital processing; the signal processing and transmission module includes a signal processing circuit and a data transmission circuit for mixing, extracting, filtering and uploading to the display and control module of the digitally processed signal of the receiving module; the display and control The module is mainly used for mode control and data processing of the auxiliary system; the mode control includes two modes: spectrum monitoring mode and transceiver simulation mode. 2. the high-frequency over-the-horizon radar station selection auxiliary system according to claim 1, is characterized in that: described transmitting module comprises signal synthesis circuit and power amplifier circuit, the output end of described signal synthesis circuit and the power amplifier circuit connected to the input. 3. the high-frequency over-the-horizon radar station selection auxiliary system according to claim 2, is characterized in that: described signal synthesis circuit is realized by DDS module and DAC digital-to-analog conversion circuit based on FPGA. 4. The high-frequency over-the-horizon radar station selection auxiliary system according to claim 2, characterized in that: the output signal power of the power amplifier circuit is about 1W, and the transmission can be realized without a high-power transmitter. 5. the high-frequency over-the-horizon radar station selection auxiliary system according to claim 1, is characterized in that: described receiving module comprises band-pass filter circuit, amplifying circuit and ADC sampling circuit, the output end of described band-pass filter circuit It is connected with the input terminal of the amplifying circuit, and the output terminal of the amplifying circuit is connected with the input terminal of the ADC sampling circuit. 6. the high-frequency over-the-horizon radar station selection auxiliary system according to claim 1, is characterized in that: described signal processing and transmission module mainly comprise the digital frequency down-conversion based on FPGA, extract, filter module, data transmission adopts USB interface or network port. 7. The high-frequency over-the-horizon radar station selection auxiliary system according to claim 1, characterized in that: the display and control module is a mobile terminal such as a notebook computer or a mobile phone. 8. a kind of method that utilizes the high-frequency over-the-horizon radar station selection auxiliary system described in claim 1 to carry out the high-frequency over-the-horizon radar station selection method, utilize the working mode of the described high-frequency over-the-horizon radar station selection auxiliary system to simulate radar, come comprehensive Test the environmental conditions of the site selection of the radar station, analyze the influence of environmental factors on the radar work by detecting echoes, and finally select a suitable station building location according to the measurement results; it is characterized in that it includes the following steps: Step 1: Utilize the transceiving simulation mode of the high-frequency over-the-horizon radar station selection auxiliary system to simulate the working mode of the radar, and evaluate the echo quality of the proposed site location in the determined site area; its specific implementation process It is to use the high-frequency over-the-horizon radar station selection auxiliary system to simulate the working state of the high-frequency over-the-horizon radar in this frequency band, transmit the waveform of the same system, and evaluate the echo distance-Doppler spectrum received by it. Comparative analysis determines that the place with relatively high echo quality is the place where the station can be built, and provides a quantitative basis for the site selection of high-frequency over-the-horizon radar stations; Step 2: Utilize the spectrum monitoring mode of the high-frequency over-the-horizon radar station selection auxiliary system to detect the electromagnetic environment at the proposed site; at this time, the high-frequency over-the-horizon radar station selection auxiliary system does not launch, but only receives echoes; according to Spectrum detection mode receives environmental noise and interference signals, through spectrum analysis, makes statistics on noise and interference data, and gives a spectrum distribution map, which provides a basis for the high-frequency over-the-horizon radar to select a working frequency with relatively small noise and interference; Step 3: Combining the results of the first two steps and comprehensively evaluating other environmental factors, determine a suitable site for site construction. 9. The method according to claim 8, characterized in that: other environmental factors mentioned in step 3 include natural environment (including marine geographical environment), electromagnetic environment and water source, power supply, transportation and communication.