A radiation source generating device for lightning detection system positioning accuracy verification

Abstract

This utility model discloses a radiation source generating device for verifying the positioning accuracy of a lightning detection system, within the field of lightning detection technology. The device includes a central control unit connected to an arbitrary waveform generator, a GPS receiver, and a radio frequency processing unit, which is connected to an antenna. This enables high-precision positioning accuracy verification of the lightning detection system with adjustable three-dimensional spatial position. Furthermore, the radiation source transmitting device can simulate lightning radiation sources of corresponding frequency bands according to the requirements of different frequency band lightning detection systems. It can accurately record the precise time and spatial position of the lightning radiation source used for network accuracy verification, significantly improving verification accuracy. The device is flexible and lightweight, and can be equipped with a drone, allowing accuracy verification experiments to be conducted at any location within the detection network without involving actual lightning discharge events, thus providing excellent safety.

Description

Technical Field

[0001] This utility model relates to a radiation source generating device for verifying the positioning accuracy of a lightning detection system in the field of lightning detection technology. Background Technology

[0002] Lightning, a common natural disaster, poses a serious threat to social production and safety. To improve lightning protection and research on lightning discharge, higher requirements are placed on the accuracy of lightning discharge process observation. Currently, lightning detection methods mainly rely on multi-station network observation systems, and the system's positioning accuracy directly affects its stability assessment. Therefore, efficient accuracy verification methods for lightning detection systems play a crucial role in the construction of lightning detection system networks.

[0003] Currently, the primary method for verifying the accuracy of lightning detection systems is through artificially triggered lightning experiments. These experiments involve using rocket-triggered lightning to initiate lightning strikes, recording the precise coordinates of the known trigger point and the time of successful triggering as the lightning's spatiotemporal location information, and comparing this information with the positioning results obtained from the lightning detection system. Its main advantage is the clear location of the lightning trigger point, resulting in relatively accurate verification results, making it the primary method for verifying the accuracy of lightning detection systems. However, it also has significant drawbacks. For example, it can only verify the two-dimensional planar spatial positioning accuracy within the detection range of the station network, and cannot provide altitude positioning errors. Furthermore, the verification experiments require specific thunderstorm weather and site conditions, and the suitable weather windows are usually limited, restricting the number and diversity of lightning samples. The required equipment includes rocket-triggered lightning devices, high-speed cameras, and high-precision radar, involving factors such as manpower scheduling and safety assurance, resulting in high experimental costs. In addition, the experiments are usually conducted within a specific, small area, and the results may only apply to that specific region, failing to verify the system's positioning accuracy across the entire area, multiple dimensions, and a wide frequency band. Utility Model Content

[0004] The purpose of this invention is to provide a radiation source generating device for verifying the positioning accuracy of a lightning detection system. The device is delivered into the observation range of the station network using a drone as a carrier, enabling the verification of positioning accuracy at any spatial location within the lightning detection system of different frequency bands.

[0005] To achieve the above objectives, this utility model provides a radiation source generating device for verifying the positioning accuracy of a lightning detection system, comprising a central control unit, which is connected to an arbitrary waveform generator, a GPS receiver, and a radio frequency processing unit, and the radio frequency processing unit is connected to an antenna.

[0006] Compared with existing technologies, the advantages of this invention are as follows: when the UAV delivers the radiation source generator to a designated spatial location, the generator emits lightning pulse signals of a specific frequency band and records the spatiotemporal location information of the actual lightning pulses. After the lightning signal is transmitted to the lightning detection system, it is received by multiple detection substations and the lightning radiation source location is calculated using a lightning positioning algorithm. The error between the radiation source location calculated by the lightning detection system and the actual radiation source location is the positioning accuracy error of the lightning detection system. This achieves high-precision positioning accuracy verification of the lightning detection system with adjustable three-dimensional spatial position. Furthermore, the radiation source transmitter can simulate lightning radiation sources of corresponding frequency bands according to the requirements of different frequency band lightning detection systems. It can accurately record the precise time and spatial location of lightning radiation sources used for station network accuracy verification, significantly improving verification accuracy. The overall design is flexible and lightweight, and equipped with a UAV, it can conduct accuracy verification experiments at any location within the detection network without involving actual lightning discharge events, thus providing excellent safety.

[0007] As a further improvement of this utility model, the arbitrary waveform generator includes a main control FPGA, which is connected to multiple baseband waveform memories. The multiple baseband waveform memories are connected to a high-speed digital-to-analog converter, the high-speed digital-to-analog converter is connected to an output amplifier, the output amplifier is connected to an SMA bus, and the SMA bus is connected to a radio frequency processing unit.

[0008] In this way, the main control FPGA sends instructions to multiple baseband waveform memories, which in turn select a specified waveform from the memory and send it to the high-speed digital-to-analog converter to generate a lightning waveform in a preset frequency band. The waveform is then sent to the radio frequency processing unit via the output amplifier 2.34 and the SMA bus for radio frequency processing.

[0009] As a further improvement of this utility model, the main control unit includes an ARM host, which is connected to a DC power supply and a memory, and is also connected to a main control FPGA and a radio frequency processing unit.

[0010] In this way, the DC power supply is connected to the ARM host and supplies power to the entire device. The ARM host is also responsible for sending instructions to the main control FPGA to generate waveforms, and it also receives the waveform signals output by the radio frequency processing unit and stores them in the memory.

[0011] As a further improvement of this utility model, the radio frequency processing unit includes a frequency synthesizer, which is connected to the ARM host and a mixer respectively. The mixer is connected to the SMA bus and a filter respectively. The filter is connected to a power amplifier. The power amplifier is connected to the ARM host and an antenna respectively.

[0012] In this way, the arbitrary waveform generator sends the output waveform to the mixer, which mixes the waveform with the local oscillator signal generated by the frequency synthesizer to generate the target radio frequency signal. Then, the target radio frequency signal is filtered to remove noise and harmonic interference before being sent to the power amplifier. The power amplifier then transmits the amplified radiation source signal to the ground receiving station through the antenna.

[0013] As a further improvement of this utility model, the GPS receiver is connected to both the ARM host and the main control FPGA.

[0014] In this way, the GPS receives GPS satellite signals and provides a precise timestamp and a 1PPS clock. The time information is sent to the ARM host to synchronize the device's time, which facilitates the subsequent recording of the spatial location and time information corresponding to the lightning radiation source. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the device structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the composition and structure of the arbitrary waveform generator of this utility model.

[0017] Figure 3 This is a schematic diagram of the structure of this utility model installed on a drone.

[0018] Among them, 1 is a drone and 2 are radiation source generating devices. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings: like Figure 1-3 The radiation source generating device shown is used for verifying the positioning accuracy of a lightning detection system. It includes a central control unit, which is connected to an arbitrary waveform generator, a GPS receiver, and a radio frequency processing unit. The radio frequency processing unit is connected to an antenna.

[0020] The arbitrary waveform generator includes a main control FPGA, which is connected to multiple baseband waveform memories. The multiple baseband waveform memories are connected to a high-speed digital-to-analog converter, which is connected to an output amplifier. The output amplifier is connected to an SMA bus, which is connected to an RF processing unit.

[0021] The main control unit includes an ARM host, which is connected to a DC power supply and a memory. The ARM host is also connected to the main control FPGA and the radio frequency processing unit.

[0022] The radio frequency processing unit includes a frequency synthesizer, which is connected to the ARM host and a mixer. The mixer is connected to the SMA bus and a filter. The filter is connected to a power amplifier. The power amplifier is connected to the ARM host and an antenna.

[0023] The GPS receiver is connected to both the ARM host and the main control FPGA.

[0024] In this invention, the main body of the radiation source generating device 2 consists of a GPS receiver, an ARM host, an arbitrary waveform generator, a frequency synthesizer, a mixer, a filter, a power amplifier, an antenna, a DC power supply, and a memory. The ARM host is responsible for coordinating the work of all hardware components, such as: reading the GPS receiver; controlling the mixer clock frequency to set the transmitter's operating frequency band; and storing the current location and time information of the transmitter. The GPS receiver is used to receive GPS satellite signals and provide a precise timestamp and a 1PPS clock (one pulse signal per second). The GPS signal can provide system time synchronization with an accuracy of ±20 nanoseconds, ensuring accurate timing of the transmitted signal. The arbitrary waveform generator, based on the 1PPS clock signal from GPS, triggers the generation of the intermediate frequency output of the equivalent arbitrary waveform excitation required by the subsequent system, used to simulate lightning pulse waveforms or other excitation signals. According to the station network detection frequency band requirements, multiple baseband waveforms required can be pre-synthesized and stored in the arbitrary waveform generator. The radio frequency processing module (frequency synthesizer, mixer, filter, power amplifier): the frequency synthesizer is used to generate the local oscillator signal required by the system. The mixer is primarily responsible for mixing the baseband signal generated by the arbitrary waveform generator with the local oscillator signal to produce the desired target RF signal. A suitable local oscillator frequency is selected based on the design goals, ensuring the output frequency covers 27~60 MHz. The filter ensures the signal is pure in the target frequency band, reducing unnecessary harmonics and spurious signals. The power amplifier amplifies the low-power RF signal output from the mixer, outputting a 10Watt (+40dBm) RF power signal to drive the antenna to transmit the signal. The antenna transmits the lightning signal as electromagnetic waves.

[0025] After the UAV 1 delivers the radiation source generator 2 to the designated spatial location, the radiation source generator 2 emits a lightning pulse signal in a specific frequency band and records the spatiotemporal location information of the actual lightning pulse. The lightning signal is transmitted to the lightning detection system, where multiple detection substations receive it and, combined with a lightning positioning algorithm, calculate the location of the lightning radiation source. The error between the radiation source location calculated by the lightning detection system and the actual radiation source location is the positioning accuracy error of the lightning detection system.

[0026] The main workflow of radiation source generating device 2 includes two parts: preparation before radiation source generation and radiation source generation itself. The preparation workflow before radiation source generation is as follows: The GPS receiver in radiation source generating device 2 receives GPS satellite signals and provides a precise timestamp and a 1PPS clock. This time information is sent to the ARM host for system time synchronization, facilitating subsequent recording of the spatial location and time information corresponding to the lightning radiation source. The ARM host communicates with the arbitrary waveform generator, frequency synthesizer, and power amplifier to set the pre-emission state of the radiation source: determining the type of baseband waveform emitted by the arbitrary waveform generator, setting the frequency range of the local oscillator signal generated by the frequency synthesizer, and determining the operating range of the power amplifier. Simultaneously, the operating status of the above components is monitored.

[0027] Lightning source generation process: Each time a 1PPS pulse arrives, the 1PPS signal generated by the GPS receiver is sent to the waveform generator, triggering the arbitrary waveform generator to generate a preset lightning baseband waveform in the 25MHz±3 high-frequency band. The arbitrary waveform generator can preset various possible transmission waveforms and store them in the waveform generator, awaiting waveform specification commands from the ARM host. This waveform can be used for research and algorithm improvement. The ARM host uses the GPS receiver signal and timestamp data at the time of the lightning source transmission to record the spatial location and time information corresponding to the lightning radiation source. The arbitrary waveform generator sends the generated waveform to the mixer, preparing for subsequent RF processing. The frequency synthesizer generates the local oscillator signal required by the system, providing a highly stable and low-phase-noise local oscillator signal output. The mixer mixes the signal output from the arbitrary waveform generator with the local oscillator signal generated by the frequency synthesizer to generate the target RF signal. The signal is then filtered to remove clutter and harmonic interference before being sent to the power amplifier. The amplified lightning source signal is then transmitted through the antenna by the power amplifier, thus completing the complete lightning radiation source signal simulation transmission process. The time and space information of each VHF lightning radiation source signal transmitted is stored in the memory, and the device is powered by a DC power supply.

[0028] Lightning waveform generation is the core of this invention, achieved through the coordinated operation of an arbitrary waveform generator, a frequency synthesizer, and a mixer. For example... Figure 2As shown, the arbitrary waveform generator consists of a main control FPGA1, multiple baseband waveform memories, a high-speed digital-to-analog converter, an output amplifier, and an SMA bus. The preset analog lightning pulse baseband waveform is typically a short-duration, high-peak pulse signal, such as a Gaussian pulse signal. Multiple preset baseband waveforms with adjustable current waveform parameters (frequency, amplitude, duration) can be generated according to verification needs, then converted into intermediate frequency modulated signals and stored in the multiple baseband waveform memories. When a 1PPS signal arrives at the arbitrary waveform generator, the main control FPGA issues a control command to select a specified waveform from the multiple baseband waveform memories and send it to the high-speed digital-to-analog converter to generate a lightning waveform in the preset frequency band. This waveform is then sent to the mixer via the output amplifier and the SMA bus for RF processing. The arbitrary waveform generator generates arbitrary waveform signals in the preset frequency band through a high-speed digital-to-analog converter and digital processing technology. Compared to traditional analog signal generators, the arbitrary waveform generator can generate more complex and accurate waveforms and phases, making it suitable for various application scenarios. It also supports multiple signal modulation methods such as amplitude modulation, frequency modulation, and phase modulation to ensure effective transmission of the radiation source signal during propagation.

[0029] The frequency synthesizer employs digital phase-locked loop (PLL) technology to multiply or divide the reference frequency signal to generate the desired local oscillator signal. PLL technology enables high-precision frequency synthesis, offering advantages such as higher frequency stability and lower phase noise, thus meeting the demands of high-precision radio frequency signal processing.

[0030] The mixer, based on the nonlinear principle of diodes and transistors, transforms a preset waveform signal generated by an arbitrary waveform generator and a local oscillator signal generated by a frequency synthesizer into output signals of different frequencies. By setting an appropriate local oscillator frequency, an adjustable analog waveform in the 27~60 MHz frequency band can be output. The mixed analog waveform is then sent to the RF processing module for further signal processing.

[0031] This invention can accurately record the precise time and spatial location of lightning radiation sources used for station network accuracy verification, significantly improving verification accuracy. It is flexible and lightweight overall, and can be equipped with a drone, allowing accuracy verification experiments to be conducted at any location within the detection network. It can achieve positioning accuracy verification at any three-dimensional spatial location within the station network detection range. It can emit lightning radiation source signals with adjustable frequency bands, and can simulate lightning radiation sources of corresponding frequency bands according to the needs of different frequency band lightning detection systems. It does not involve real lightning discharge events, thus having excellent safety.

[0032] This utility model is not limited to the above embodiments. Based on the technical solutions disclosed herein, those skilled in the art can make some substitutions and modifications to some of the technical features without creative labor, and these substitutions and modifications are all within the protection scope of this utility model.

Claims

1. A radiation source generating device for verifying the positioning accuracy of a lightning detection system, characterized in that: It includes a central control unit, which is connected to an arbitrary waveform generator, a GPS receiver, and a radio frequency processing unit, and the radio frequency processing unit is connected to an antenna; The arbitrary waveform generator includes a main control FPGA, which is connected to multiple baseband waveform memories. The multiple baseband waveform memories are connected to a high-speed digital-to-analog converter. The high-speed digital-to-analog converter is connected to an output amplifier. The output amplifier is connected to an SMA bus. The SMA bus is connected to a radio frequency processing unit. The radio frequency processing unit includes a frequency synthesizer, which is connected to the ARM host and a mixer. The mixer is connected to the SMA bus and a filter. The filter is connected to a power amplifier. The power amplifier is connected to the ARM host and an antenna.

2. The radiation source generating device for verifying the positioning accuracy of a lightning detection system according to claim 1, characterized in that: The main control unit includes an ARM host, which is connected to a DC power supply and a memory. The ARM host is also connected to the main control FPGA and the radio frequency processing unit.

3. The radiation source generating device for verifying the positioning accuracy of a lightning detection system according to claim 2, characterized in that: The GPS receiver is connected to both the ARM host and the main control FPGA.

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