Atmospheric optical parameter real-time inversion device and method based on ZYNQ

Abstract

The application discloses a kind of based on ZYNQ atmospheric optical parameter real-time inversion device and method, device includes ZYNQ chip, the ZYNQ chip module includes the programmable logic system PL and processor system PS that information interaction is realized by bus, the programmable logic system PL is used to obtain after sampling point number real-time acquisition the cumulative data corresponding to the sampling point number, and the cumulative data is transmitted into processor system PS, the processor system PS is used to send control signal to programmable logic system PL control acquisition cumulative data, and original signal is obtained by correcting cumulative data, and atmospheric optical parameter is obtained based on the original signal inversion, and original signal and inversion result are transmitted or stored.The application is based on the board card system of ZYNQ chip on the basis of laser radar echo signal acquisition, cumulative data obtained in real time is inverted, and inversion result and original signal are output simultaneously, so as to improve the real-time performance of data.

Description

Technical Field

[0001] This invention belongs to the field of atmospheric sounding, and particularly relates to a real-time inversion device and method for atmospheric optical parameters based on ZYNQ. Background Technology

[0002] After acquiring atmospheric echo signals, lidar obtains atmospheric optical parameters through data inversion and analysis. Lidar systems based on this detection method have high spatiotemporal resolution and high detection accuracy.

[0003] Currently, the inversion calculations for atmospheric sounding lidar echo signals all involve using pre-written host computer inversion software to perform inversion operations on the acquired echo signals, or using custom-written inversion algorithms in numerical calculation software to perform signal inversion calculations, ultimately obtaining optical parameter information of various particles in the atmosphere. The former requires pre-written inversion software adapted to the operating system, while the latter requires inversion calculations in numerical calculation software after acquiring raw atmospheric data, and cannot obtain real-time atmospheric optical parameter information, making it unsuitable for different application scenarios and causing inconvenience in engineering applications. Existing atmospheric sounding lidar acquisition systems only achieve the acquisition and transmission of raw signals, and cannot perform real-time inversion of the raw signals to obtain real-time atmospheric optical parameter information and transmit this information in real time. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a real-time atmospheric optical parameter inversion device and method based on ZYNQ, the specific technical solution of which is as follows:

[0005] A real-time atmospheric optical parameter inversion device based on ZYNQ includes a ZYNQ chip. The ZYNQ chip module includes a programmable logic system (PL) and a processor system (PS) that interact via a bus. The PL is used to acquire the number of sampling points and then acquire the accumulated data corresponding to the number of sampling points in real time, and transmit the accumulated data to the processor system (PS). The PS is used to send control signals to the PL to control the acquisition of the accumulated data, perform correction processing on the accumulated data to obtain the original signal, obtain the inversion result based on the original signal, and store the original signal and the inversion result.

[0006] Optionally, the programmable logic system PL includes:

[0007] The data acquisition control unit interacts with the processor system PS to acquire the control signal including the number of acquisition points and the cumulative number of times N; and determines the acquisition status based on the externally input trigger signal, the acquisition status including acquisition, idle and delay.

[0008] A real-time accumulation unit is connected to the acquisition control unit to obtain the acquisition status, number of acquisition points, and cumulative count N; and is connected to the sampling data conversion module to obtain the sampling data when the acquisition status is acquisition; and obtains the accumulated data based on the number of acquisition points, cumulative count N, and sampling data.

[0009] The cache unit is used to retrieve the accumulated data corresponding to the Nth accumulation.

[0010] Optionally, the processor system PS includes an APU, DDR3 memory, and port units, wherein the APU includes:

[0011] The first correction subunit is used to acquire the accumulated data in the programmable logic system PL and correct the accumulated data to obtain the original signal;

[0012] A storage controller is used to control the DDR3 memory to acquire and store the original signal and the inversion result;

[0013] The inversion unit is used to perform atmospheric optical parameter inversion on the original signal to obtain inversion results including extinction coefficient and backscattering coefficient;

[0014] The DDR3 memory is used to store the original signal and the inversion results;

[0015] The port unit is connected to the DDR3 memory and is used to obtain external instructions, specify the number of sampling points and the number of accumulations N, and also to output the original signal and the inversion result to the outside.

[0016] Optionally, the processor system PS further includes an SD NAND storage controller, which is connected to the DDR3 memory to obtain DDR3 memory data. The processor system PS also includes an Ethernet controller ENET, which interacts with the DDR3 memory to exchange information and outputs the raw data and inversion results stored in the DDR3 memory.

[0017] Optionally, the inversion unit includes the following components arranged sequentially:

[0018] The noise removal subunit is used to denoise the accumulated data and remove background noise;

[0019] The data smoothing subunit performs multi-point smoothing of the accumulated data after removing background noise using a triangular smoothing method.

[0020] The distance square correction subunit is used to square the distance of the data output by the data smoothing subunit in order to eliminate the influence of distance on signal strength;

[0021] Determine the calibration point sub-unit to obtain the calibration point where the aerosol scattering ratio is set to the set value;

[0022] The inversion calculation subunit performs backward integration on the atmospheric space before the calibration point and forward integration on the data points after the calibration point to obtain inversion results including extinction coefficient and backscattering coefficient.

[0023] Optionally, the ZYNQ chip is an FPGA chip, and the device further includes components mounted on the FPGA board:

[0024] A trigger module, connected to the acquisition and control unit, is used to send a trigger signal to the acquisition and control unit;

[0025] The AD sampling module is connected to the real-time accumulation unit and the acquisition control unit. It is used to collect external signals, process the signals and send them to the real-time accumulation unit, and send the DCO clock signal to the acquisition control unit and obtain the ENC clock signal of the acquisition control unit.

[0026] Optionally, the triggering module includes a gating circuit, an optocoupler triggering circuit connected to the gating circuit, and a comparator triggering circuit.

[0027] Optionally, the AD sampling module includes the following components configured sequentially:

[0028] The filtering circuit, including a Bessel filter, is used to filter the signal obtained by the lidar detection.

[0029] The gain adjustment circuit is an inverting proportional amplifier circuit used to adjust the gain of the filtered circuit.

[0030] A single-ended to differential circuit is used to convert a single-ended signal into a differential signal.

[0031] The analog-to-digital conversion circuit includes a multi-channel multi-bit analog-to-digital converter for converting analog signals into digital signals, and each channel outputs a corresponding DCO clock signal, which is used to ensure that the receiving logic has the correct latching timing.

[0032] The method using the ZYNQ-based real-time atmospheric optical parameter inversion device described above includes:

[0033] The processor system PS receives external control commands, obtains the specified number of sampling points and the number of accumulations, and transmits them to the programmable logic system PL via the bus; the programmable logic system PL detects whether there is an external trigger signal input, and determines the acquisition status of the programmable logic system PL based on the detection result;

[0034] When the acquisition status is a trigger signal indicating acquisition, the programmable logic system (PL) acquires the acquired data and the previously accumulated data stored internally in real time. Based on the acquired data, it accumulates the data again based on the previously accumulated data, repeating the accumulation step until the accumulation number is N. Then, the accumulated data is stored and sent to the processor system (PS) via the bus. After calibration, the original signal is obtained and stored in the DDR3 memory under the control of the storage controller. At the same time, the processor system (PS) performs atmospheric optical parameter inversion on the original signal and stores the inversion result in the DDR3 memory under the control of the storage controller.

[0035] Furthermore, after accumulating N times, the accumulated data is stored and sent to the processor system PS via the bus. After calibration, the original signal is obtained. The original signal is stored in the storage controller of the processor system PS. After storing the inversion result in the storage controller of the processor system PS, the process also includes:

[0036] The storage controller in the APU determines whether the Ethernet is normal. When it is normal, the storage controller in the APU outputs the raw signal and atmospheric optical parameters stored in the DDR3 memory through the Ethernet port. When it is abnormal, the storage controller in the APU stores the raw signal and atmospheric optical parameters stored in the DDR3 memory into the SD NAND memory, and outputs them after the network is restored to normal.

[0037] (1) Based on the acquisition of atmospheric lidar echo signals, this invention corrects the accumulated signals acquired in real time in the board system to obtain the original signal, and then performs inversion. The atmospheric optical parameters obtained by inversion are output together with the original signal. The programmable logic system (PL) and the processor system (PS) work in parallel. When the PL is acquiring and accumulating data, the PS is simultaneously performing inversion. After the PL completes the accumulation, it sends an interrupt request to the PS. The PS reads the accumulated data for subsequent processing, while the PL continues to execute the next round of acquisition and accumulation. This obtains real-time atmospheric optical parameters, improving the real-time performance of the data.

[0038] (2) The acquisition and inversion are integrated into a single circuit board card, which can realize the inversion function without the need for an operating system. There is no need to worry about software crashes caused by the complexity of the operating system, which improves the system's integration, working stability and portability, and enables the system to adapt to more application scenarios.

[0039] (3) This invention combines two triggering methods. The optocoupler triggering circuit has the characteristics of electrical isolation and strong anti-interference ability, while the comparator triggering circuit has the characteristics of fast response speed and high time resolution. The appropriate triggering method can be selected by the gating circuit in different scenarios, which improves the reliability and anti-interference ability of the system and expands the application scenarios of the system.

[0040] (4) The filtering circuit uses a Bessel filter. The bandwidth of the Bessel filter and the parameters of the devices used are determined according to the frequency characteristics of the signal to be acquired. The bandwidth and device parameters are adjustable. Without affecting the signal to be acquired, out-of-band noise is filtered out, and the anti-interference capability of the acquisition system is improved.

[0041] (5) The accumulated data and inversion results of this application are transmitted to an external receiving end via Ethernet. In the event of network failure, the information is stored in the SD NAND memory in real time to avoid data loss in the event of failure to transmit in real time. Attached Figure Description

[0042] Figure 1 This is a hardware circuit diagram of a ZYNQ-based real-time atmospheric optical parameter inversion device.

[0043] Figure 2 This is a flowchart of the data collection process.

[0044] Figure 3 The logic block diagram for the data acquisition and inversion module.

[0045] Figure 4 This is a flowchart of the real-time inversion module. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In the description of the embodiments of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0047] Currently, there are two main approaches to inverting atmospheric optical parameters from lidar echo signals. The first involves using pre-written host computer inversion software to perform the inversion calculations on the acquired echo signals. The second involves using a custom-written inversion algorithm on a personal computer's numerical calculation software to perform the signal inversion calculations. The first approach requires an industrial control computer within the lidar system, where the inversion process is implemented. This reduces the system's reliability, security, and portability. The second approach also relies on numerical calculation software on a personal computer's operating system and cannot acquire atmospheric optical parameter information.

[0048] To solve the above problems, such as Figure 1 and Figure 3 As shown, this application discloses a real-time atmospheric optical parameter inversion device based on ZYNQ, including a ZYNQ chip. The ZYNQ chip module includes a programmable logic system (PL) and a processor system (PS) that interact via a bus. The PL is used to acquire the number of sampling points and then acquire the accumulated data corresponding to the number of sampling points in real time, and transmit the accumulated data to the processor system (PS). The PS is used to send control signals to the PL to control the acquisition of the accumulated data, perform correction processing on the accumulated data to obtain the original signal, obtain the inversion result based on the original signal, and store the original signal and the inversion result.

[0049] In one embodiment, the ZYNQ chip is a ZYNQ-7000 series SoC FPGA chip. The real-time inversion unit in this invention is located within the ARM Cortex-A9 of the ZYNQ chip. The chip is programmed using Verilog hardware description language in the programmable logic system (PL), and its processor system (PS) is programmed using C language to implement the acquisition function of the acquisition module and the inversion operation function of the real-time inversion module in this invention.

[0050] Specifically, the programmable logic system (PL) includes a data acquisition control unit, a real-time accumulation unit, and a cache unit. The data acquisition control unit is connected to the processor system (PS) and is used to acquire the number of acquisition points and the cumulative count N; and to determine the acquisition state based on a trigger signal, whereby the acquisition state includes acquisition, idle, and delay. The real-time accumulation unit is connected to the data acquisition control unit and is used to acquire the acquisition state, the number of acquisition points, and the cumulative count N; it is also connected to a sampled data conversion module and is used to acquire sampled data when the acquisition state is acquisition; and to obtain accumulated data based on the number of acquisition points, the cumulative count N, and the sampled data; the cache unit is used to acquire the accumulated data corresponding to the Nth cumulative count.

[0051] like Figure 3As shown, in one embodiment, the programmable logic system PL further includes a control register disposed between the acquisition control unit and the bus AXI, for storing the number of acquisition points and the cumulative number of acquisitions from the processor system PS to the acquisition control unit.

[0052] like Figure 3 As shown, in one embodiment, the cache unit includes BRAM0, BRAM1, and an AXI BRAM controller. BRAM0 is used to write the i-th accumulated data (where i is the accumulation count, ranging from 1 to N-1), and returns the i-th accumulated data to the real-time accumulation unit to obtain the (i+1)-th accumulated data. BRAM1 is used to write the N-th accumulated data, and the AIX BRAM controller controls the transmission of the accumulated data to the processor system PS via the AXI bus.

[0053] Specifically, the processor system PS includes an APU, a DDR3 memory, and port units. The APU includes a first correction subunit, a memory controller, and an inversion unit. The first correction subunit is used to acquire accumulated data in the programmable logic system PL and correct the accumulated data to obtain the original signal. The memory controller is used to control the DDR3 memory to acquire and store the original signal and the inversion result N. The inversion unit is used to perform atmospheric optical parameter inversion on the original signal to obtain inversion results including extinction coefficient and backscattering coefficient. The DDR3 memory is connected to the memory controller and is used to store the original signal and the inversion result. The port units are connected to the DDR3 memory and are used to acquire external instructions, specifying the number of sampling points and the number of accumulations N, and also to output the original signal and the inversion result to the outside.

[0054] Specifically, the inversion unit includes, in sequence, a noise removal subunit, a data smoothing subunit, a distance squared correction subunit, a calibration point determination subunit, and an inversion calculation subunit. The noise removal subunit denoises the accumulated data to remove background noise; the data smoothing subunit performs multi-point smoothing on the noise-removed accumulated data using triangular smoothing; the distance squared correction subunit squares the distance in the data output by the data smoothing subunit to eliminate the influence of distance on signal strength; the calibration point determination subunit obtains calibration points with a set aerosol scattering ratio; and the inversion calculation subunit performs backward integration on the atmospheric space before the calibration point and forward integration on the data points after the calibration point to obtain the inversion result including the extinction coefficient and the backscattering coefficient.

[0055] The first correction subunit includes an acquisition control and read / write section and an accumulated data correction section. It is used to acquire accumulated data from the programmable logic system (PL) via the AXI bus, correct the accumulated data using the accumulated data correction section to obtain the original signal, and then store the original signal in the storage controller. Additionally, the acquisition control and read / write section transmits external signals input via the processor system's PS connection port to the PL. These external signals include the number of sampling points and the number of accumulations N.

[0056] In one embodiment, the processor system PS further includes an SD NAND storage controller connected to the DDR3 memory to acquire DDR3 memory data. The processor system PS also includes an Ethernet controller ENET, which interacts with the DDR3 memory to output the raw data stored in the DDR3 memory and the inversion results. In one scheme, both the SD NAND storage controller and the Ethernet controller ENET are connected to external devices via MIO ports.

[0057] like Figure 1 As shown, the ZYNQ chip is an FPGA chip, and the device also includes a trigger module, an AD sampling module, and a real-time clock module mounted on the FPGA board. The trigger module is connected to the acquisition control unit and is used to send a trigger signal to the acquisition control unit; the AD sampling module is connected to the real-time accumulation unit and the acquisition control unit, and is used to acquire external signals, process the signals and send them to the real-time accumulation unit, and send a DCO clock signal to the acquisition control unit and acquire the ENC clock signal of the acquisition control unit.

[0058] The trigger module includes a gating circuit, an optocoupler trigger circuit connected to the gating circuit, and a comparator trigger circuit. The core component of the optocoupler trigger circuit is a logic output optocoupler, consisting of a light-emitting diode (LED) and a photosensitive receiver (such as a phototransistor, photodiode, or phototransistor). These two parts are encapsulated in a black package to prevent external light interference, and there is no electrical connection between them; they interact only through light signals. When a logic high-level signal (or logic low-level signal, depending on the type of optocoupler) is received at the input, the LED lights up, and the emitted light signal propagates inside the optocoupler. The photosensitive receiver (such as a phototransistor) receives the light signal and converts it into a corresponding electrical signal based on the light intensity, realizing the "electrical-optical-electrical" conversion of the input trigger signal and outputting a standard digital logic level to trigger the acquisition. The output electrical signal is logically consistent with (or designed to be the opposite of) the input electrical signal, but they are electrically isolated, effectively isolating the trigger input and acquisition end of the acquisition control system and protecting the acquisition control system from interference from the trigger input signal. The core component of a comparator trigger circuit is the comparator itself. In this circuit, a stable reference voltage is set as the trigger threshold. The input signal is fed into the non-inverting input (usually the "+" input) of the comparator, and the inverting input (usually the "-" input) is connected to the set reference voltage. When the input signal voltage is higher than the reference voltage, the comparator outputs a high-level signal (usually close to the power supply voltage). When the input signal voltage is lower than the reference voltage, the comparator outputs a low-level signal (usually close to ground or zero voltage). Changes in the output signal level can serve as a trigger event, controlling the data acquisition action of the connected FPGA. Depending on the settings, the gating circuit can meet the triggering requirements of various scenarios. For example, a comparator trigger circuit can be used for high-speed data acquisition, while an optocoupler trigger circuit can be used to achieve electrical isolation when external interference needs to be avoided.

[0059] In one embodiment, the AD sampling module includes a filtering circuit, a gain adjustment circuit, a single-ended to differential circuit, and an analog-to-digital converter (ADC) circuit arranged sequentially. The filtering circuit includes a Bessel filter for filtering the signal obtained from the lidar detection; the gain adjustment circuit is an inverting amplifier circuit for adjusting the gain of the filtered circuit; the single-ended to differential circuit converts the single-ended signal into a differential signal; the ADC circuit includes a multi-channel multi-bit analog-to-digital converter (ADC) for converting the analog signal into a digital signal, and each channel outputs a corresponding DCO clock signal, which ensures the receiving logic has correct latching timing. Specifically, the AD acquisition module includes a filtering circuit, a gain adjustment circuit, a single-ended to differential circuit, and an ADC circuit. The filtering circuit uses an LC-type Bessel filter, which has very small gain variation in the passband, remaining almost flat, and a fast attenuation rate in the stopband, quickly suppressing unwanted frequencies and possessing linear phase characteristics, which helps maintain the signal waveform. This circuit consists of series-connected LC resonant circuits, forming a π-shaped structure. The selection of LC components depends on the required filter characteristics. In this application, by performing spectral analysis on typical signals acquired by the system board, the frequency characteristics and spectral information of the time-domain details of the signal to be acquired are obtained. The bandwidth of the Bessel filter and the required device parameters are determined. By adjusting the parameters of the components used, the bandwidth of the filter is changed, filtering out-of-band noise without affecting the signal to be acquired, thus improving the signal's anti-interference capability. The gain adjustment circuit and the single-ended to differential circuit consist of a fully differential operational amplifier and its peripheral circuits. The single-ended signal is first input to one input terminal of the differential amplifier, and the other input terminal is connected to ground or a reference voltage. The internal circuit of the fully differential operational amplifier compares the voltages of the two input terminals (non-inverting input terminal and inverting input terminal). The output of the differential amplifier is two signals with opposite voltages, i.e., differential signals. The difference between these two output signals is the result of amplifying the input signal. In this circuit, the gain adjustment of the input signal is achieved by adjusting the ratio between the feedback resistor and the input resistor of the differential operational amplifier. The input signal passes through an input resistor (R). in ) is connected to the inverting input of the operational amplifier, while the feedback resistor (R) f The inverting input is connected between the inverting input and the non-inverting input. According to the virtual short and virtual open principles of operational amplifiers, the voltage difference between the inverting and non-inverting inputs is close to zero; therefore, the voltage at the inverting input is close to the voltage at the non-inverting input. Ideally, the gain (A) of the inverting amplifier is... v ) can be achieved through A v =-R f / R inThe calculation is performed where the negative sign indicates that the output signal is out of phase with the input signal. In a fully differential operational amplifier, the input signal typically passes through two equal input resistors (R0, R0, R0). in The inputs are respectively fed to the two input terminals (non-inverting and inverting input terminals) of the operational amplifier, while the feedback resistor (R) f Then it is connected between the two input resistors, and R is adjusted. f and R in The gain of the differential amplifier is adjusted by the ratio. The output signal of this operational amplifier circuit is a differential signal, which enters the analog-to-digital converter (ADC). The ADC circuit includes a dual-channel 14-bit ADC. This chip adopts a multi-stage differential pipeline architecture, using a single differential clock input to control all internal conversion cycles. The digital output data format is offset binary, Gray code, or two's complement. Each ADC channel has a data output clock (DCO) to ensure that the receiving logic has correct latching timing. The differential signal output from the single-ended to differential circuit enters the ADC, is converted into a 14-bit digital output signal, and then enters the FPGA chip for processing.

[0060] In one embodiment, the analog-to-digital converter (ADC) chip is an AD9251. The acquisition control unit of the programmable logic system (PL) controls the ADC circuit via the ENC clock output. The output data of the ADC circuit, along with the DCO clock input, is added to the acquisition control unit in the PL. Before acquisition begins, the external control terminal sends instructions via MIO, specifying the number of sampling points and the number of accumulations. The acquisition control unit inside the PL receives the input of an external trigger signal, detects whether a trigger signal is input, and determines the acquisition state of the PL based on the detection result. When the trigger signal has not arrived, the acquisition part of the PL is in an idle state. After the trigger signal is detected, the PL enters the acquisition state. After one acquisition is completed, the system is in a delay state until the next trigger signal arrives. When the rising edge of the trigger signal is detected, the real-time accumulation module reads the 14-bit data input from the ADC circuit and the previously accumulated data stored in BRAM0, accumulates the two data at once, and writes the accumulation result into BRAM0. When the specified accumulation count N is reached, the result of the last accumulation is stored in BRAM1. Simultaneously, the control unit of the programmable logic system (PL) sends an interrupt request to the processor system (PS). The processor system (PS), through the AXI BRAM controller (which acts as an output transmission unit), controls the AXI bus to read the accumulated data from BRAM1. The processor system (PS) corrects the accumulated data and obtains the raw signal, which is then stored in the memory controller. At the same time, the application processor unit (APU) of the processor system (PS) performs atmospheric optical parameter inversion on the raw signal. The final inversion result is stored in the memory controller, and the processor system (PS) controls the storage of the raw signal and the inversion result in the DDR3 memory. Under normal network conditions, the Ethernet reads the raw signal and the inversion result stored in the DDR3 memory and transmits them to the external receiving end via Ethernet. Under network abnormal conditions, the raw signal and the inversion result in the DDR3 memory are sent to the on-chip SD NAND memory controller. When the network connection is restored or conditions permit, the acquisition and inversion module reads the data from the SD NAND memory and re-attempts to transmit the data to the external device via Ethernet.

[0061] In another embodiment, a method for using the aforementioned ZYNQ-based real-time atmospheric optical parameter inversion device is also disclosed, comprising:

[0062] The processor system PS receives external control commands, obtains the specified number of sampling points and the number of accumulations, and transmits them to the programmable logic system PL via the bus; the programmable logic system PL detects whether there is an external trigger signal input, and determines the acquisition status of the programmable logic system PL based on the detection result;

[0063] When the acquisition status is a trigger signal indicating acquisition, the programmable logic system (PL) acquires the acquired data and the previously accumulated data stored internally in real time. Based on the acquired data, it accumulates the data again based on the previously accumulated data, repeating the accumulation step until the accumulation number is N. Then, the accumulated data is stored and sent to the processor system (PS) via the bus. After calibration, the original signal is obtained and stored in the DDR3 memory under the control of the storage controller. At the same time, the processor system (PS) performs atmospheric optical parameter inversion on the original signal and stores the inversion result in the DDR3 memory under the control of the storage controller.

[0064] Specifically, after the cumulative count reaches N, the accumulated data is stored and sent to the processor system PS via the bus for correction to obtain the original signal. The original signal is then stored in the storage controller of the processor system PS, and the inversion result is also stored in the storage controller of the processor system PS. The process further includes:

[0065] The storage controller in the APU determines whether the Ethernet is normal. When it is normal, the storage controller in the APU outputs the raw signal and atmospheric optical parameters stored in the DDR3 memory through the Ethernet port. When it is abnormal, the storage controller in the APU stores the raw signal and atmospheric optical parameters stored in the DDR3 memory into the SD NAND memory, and outputs them after the network is restored to normal.

[0066] like Figure 2 As shown, before the acquisition begins, the number of sampling points and the number of accumulations are transmitted to the system board via Ethernet. The board parses the information transmitted via Ethernet and sets the number of sampling points and the number of accumulations on the FPGA. After both parameters are set, acquisition begins, waiting for a trigger signal. If the trigger signal does not arrive, the board remains in a waiting acquisition state. After the trigger signal arrives, acquisition begins. The signal passes through the AD acquisition module and is acquired and accumulated in the programmable logic system (PL) of the ZYNQ. Before reaching the last accumulation count, the result of each accumulation is stored in the BRAM0 of the buffer unit. After reaching the set accumulation count, the result of the last accumulation is stored in the BRAM1 of the programmable logic system (PL). The processor system (PS) in the ZYNQ reads the data stored in the BRAM1 of the programmable logic system (PL) and performs subsequent inversion calculations on the corrected accumulated data.

[0067] Specifically, such as Figure 4 As shown, the processor system PS performs atmospheric optical parameter inversion on the accumulated data, including:

[0068] Import the US Standard Atmospheric Model data before starting the calculation. When the interrupt of the programmable logic system (PL) occurs, the processor system (PS) reads the accumulated data corresponding to the Nth accumulation of the programmable logic system (PL).

[0069] The accumulated data is corrected using the first correction subunit; firstly, a certain data space is allocated to the accumulated data, the accumulated data is corrected, and the magnitude of the corrected data value corresponds to the actual voltage value. The corrected data value is the original data, which corresponds to the voltage value of the actual echo signal.

[0070] The noise removal subunit is used to remove background from the original data. The background noise is subtracted from the original signal to obtain a signal with a baseline of 0.

[0071] The signal is triangularly smoothed using a data smoothing subunit, where any number of odd points can be selected for triangular smoothing; this improves the signal-to-noise ratio of the signal.

[0072] The smoothed signal is corrected by square distance using a distance square correction subunit, which multiplies the smoothed signal by the square of the distance.

[0073] The calibration point is determined using a specific calibration point sub-unit. The selection of the calibration point follows conventional experience: the range-squared correction signal is divided by the US standard atmospheric model to obtain a profile. The minimum value of this profile within a certain range is the calibration point. The determination of this range needs to be based on the hardware parameters of the lidar.

[0074] Using the inversion calculation subunit, the atmospheric optical parameters here are inverted using the extinction coefficient and backscattering coefficient of aerosol particles as examples. The inversion is based on the Fernald method. Back-integration is performed on the atmospheric space before the calibration point, and forward integration is performed on the data points after the calibration point. According to the lidar equation and the Fernald method inversion formula, the values ​​at calibration point Z are directly obtained. C The backscattering coefficient β1(Z) and extinction coefficient α1(Z) of the following aerosol particles are as follows:

[0075]

[0076]

[0077] At calibration point Z C The backscattering coefficient β1(Z) and extinction coefficient α1(Z) of the above aerosol particles are as follows:

[0078]

[0079] In the above formula, α2(Z) and β2(Z) are the extinction coefficient and backscattering coefficient of air molecules, respectively. It is the aerosol extinction backscattering ratio. In the inversion calculation, for stratospheric and tropospheric aerosols during the background period, S1 = 50. The extinction backscattering ratio of air molecules is generally taken as... X(Z c ) represents the value of the squared distance correction signal at the calibration point.

[0080] After the inversion calculation in the ARM is completed, the calculated extinction coefficient and backscattering coefficient are stored and transmitted along with the original signal. If the system receives a stop acquisition command at this time, the entire acquisition and inversion calculation process will stop. If no end acquisition command is received, the acquisition system will work normally, continuously acquiring signals and performing inversion calculations.

[0081] The inversion algorithm in the acquisition and inversion module of the above embodiments takes the inversion of aerosol optical parameters of aerosol lidar as an example. The acquisition and inversion process and framework protected by this application are also applicable to other atmospheric detection lidars, such as water vapor lidar and ozone lidar.

[0082] In the description of this specification, references to terms such as "some embodiments" or "example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0083] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A real-time atmospheric optical parameter inversion device based on ZYNQ, characterized in that, The system includes a ZYNQ chip. The ZYNQ chip module includes a programmable logic system (PL) and a processor system (PS) that interact with each other via a bus. The programmable logic system (PL) is used to acquire the number of sampling points and then acquire the accumulated data corresponding to the number of sampling points in real time. The accumulated data is then transmitted to the processor system (PS). The processor system (PS) is used to send control signals to the programmable logic system (PL) to acquire the accumulated data, perform correction processing on the accumulated data to obtain the original signal, obtain the inversion result based on the original signal, and store the original signal and the inversion result. The programmable logic system (PL) includes: The data acquisition control unit interacts with the processor system PS to acquire the control signal including the number of acquisition points and the cumulative number of times N; and determines the acquisition status based on the externally input trigger signal, the acquisition status including acquisition, idle and delay. A real-time accumulation unit is connected to the acquisition control unit to obtain the acquisition status, number of acquisition points, and cumulative count N; and is connected to the sampling data conversion module to obtain the sampling data when the acquisition status is acquisition; and obtains the accumulated data based on the number of acquisition points, cumulative count N, and sampling data. The cache unit includes a first on-chip memory BRAM0, a second on-chip memory BRAM1, and an AXI BRAM controller. BRAM0 is used to write the accumulation results sequentially during the first to N-1 accumulation processes and feed back the accumulation results to the real-time accumulation unit to obtain the next accumulation data. BRAM1 is used to write the corresponding accumulation data only during the Nth accumulation. The processor system PS includes an APU, DDR3 memory, and port units. The APU includes: The first correction subunit is used to acquire the Nth accumulated data in the programmable logic system PL and correct the Nth accumulated data to obtain the original signal. A storage controller is used to control the DDR3 memory to acquire and store the original signal and the inversion result; The inversion unit is used to perform atmospheric optical parameter inversion on the original signal to obtain atmospheric optical parameters including extinction coefficient and backscattering coefficient; The DDR3 memory is used to store the original signal and the inversion results; The port unit is connected to the DDR3 memory and is used to obtain external instructions, provide the specified number of sampling points and accumulation times N, and also to output the original signal and inversion result to the outside. The ZYNQ chip is an FPGA chip, and the device also includes components mounted on the FPGA board: A trigger module, connected to the acquisition and control unit, is used to send a trigger signal to the acquisition and control unit; The AD sampling module is connected to the real-time accumulation unit and the acquisition control unit. It is used to collect external signals, process the signals and send them to the real-time accumulation unit, and send the DCO clock signal to the acquisition control unit and obtain the ENC clock signal of the acquisition control unit. The triggering module includes a gating circuit, an optocoupler triggering circuit connected to the gating circuit, and a comparator triggering circuit. The AD sampling module includes the following components configured sequentially: The filtering circuit, including a Bessel filter, is used to filter the signal obtained by the lidar detection. The gain adjustment circuit is an inverting proportional amplifier circuit used to adjust the gain of the filtered circuit. A single-ended to differential circuit is used to convert a single-ended signal into a differential signal. The analog-to-digital conversion circuit includes a multi-channel multi-bit analog-to-digital converter for converting analog signals into digital signals, and each channel outputs a corresponding DCO clock signal, which is used to ensure that the receiving logic has the correct latching timing.

2. The apparatus according to claim 1, characterized in that, The processor system PS also includes an SD NAND storage controller, which is connected to the DDR3 memory to obtain DDR3 memory data. The processor system PS also includes an Ethernet controller ENET, which interacts with the DDR3 memory to output the raw data and inversion results stored in the DDR3 memory.

3. The apparatus according to claim 1, characterized in that, The inversion unit comprises, in sequence: The noise removal subunit is used to denoise the original signal and remove background noise; The data smoothing subunit performs multi-point smoothing of the accumulated data after removing background noise using a triangular smoothing method. The distance square correction subunit is used to square the distance of the data output by the data smoothing subunit in order to eliminate the influence of distance on signal strength; Determine the calibration point sub-unit to obtain the calibration point where the aerosol scattering ratio is set to the set value; The inversion calculation subunit performs backward integration on the atmospheric space before the calibration point and forward integration on the data points after the calibration point to obtain inversion results including extinction coefficient and backscattering coefficient.

4. A method using the ZYNQ-based real-time atmospheric optical parameter inversion device according to any one of claims 1-3, characterized in that, include: The processor system PS receives external control commands, obtains the specified number of sampling points and the number of accumulations, and transmits them to the programmable logic system PL via the bus; the programmable logic system PL detects whether there is an external trigger signal input, and determines the acquisition status of the programmable logic system PL based on the detection result; When the acquisition status is a trigger signal indicating acquisition, the programmable logic system (PL) acquires the acquired data and the previously accumulated data stored internally in real time. Based on the acquired data, it accumulates the data again from the previous accumulation, repeating the accumulation step until the cumulative number is N. Then, the corresponding Nth accumulated data is stored in BRAM1 and sent to the processor system (PS) via the bus. After receiving an interrupt request, the processor system (PS) corrects the Nth accumulated data to obtain the original signal. The original signal is then stored in the DDR3 memory under the control of the storage controller. Simultaneously, the processor system (PS) performs atmospheric optical parameter inversion on the original signal and stores the inversion result in the DDR3 memory under the control of the storage controller.

5. The method according to claim 4, characterized in that, After the cumulative count reaches N, the Nth accumulated data is stored and sent to the processor system PS via the bus. After calibration, the original signal is obtained. The original signal is stored in the storage controller of the processor system PS. After storing the inversion result in the storage controller of the processor system PS, the process further includes: The storage controller in the APU determines whether the Ethernet is normal. When it is normal, the storage controller in the APU outputs the raw signal and atmospheric optical parameters stored in the DDR3 memory through the Ethernet port. When it is abnormal, the storage controller in the APU stores the raw signal and atmospheric optical parameters stored in the DDR3 memory into the SD NAND memory, and outputs them after the network is restored to normal.

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