CN109063302B

CN109063302B - High-resolution solar radio data processing system and method for self-adaptive outbreak judgment

Info

Publication number: CN109063302B
Application number: CN201810820718.3A
Authority: CN
Inventors: 杜清府; 陈昌硕; 李昕; 程仁君; 张巧曼; 陈耀
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2018-07-24
Filing date: 2018-07-24
Publication date: 2022-11-04
Anticipated expiration: 2038-07-24
Also published as: CN109063302A

Abstract

The invention discloses a high-resolution solar radio data processing system and method for self-adaptive outbreak judgment, wherein the system comprises a parabolic antenna, a high-speed ADC (analog to digital converter) collector, an FPGA (field programmable gate array) and a computer; the parabolic antenna receives the solar radio signals and outputs two paths of antenna signals to the high-speed ADC collector; the high-speed ADC collector converts the signals into high-speed digital signals and transmits the high-speed digital signals to the FPGA; the FPGA intercepts and segments the high-speed digital signal, performs FFT operation on each segment respectively, performs digital polarization synthesis in a frequency domain to obtain circularly polarized left-handed and right-handed solar radio signals, calculates the power of the solar radio signals, performs integral operation on the power of the solar radio signals according to time resolution to obtain solar radio frequency spectrum signals, and uploads the solar radio frequency spectrum signals to a computer; the computer carries out self-adaptive explosion judgment and processing on the solar radio frequency spectrum signal, and stores the data containing the solar explosion event according to high resolution.

Description

High-resolution solar radio data processing system and method for self-adaptive outbreak judgment

Technical Field

The invention relates to the field of solar radio data processing, in particular to a high-resolution solar radio data processing system and method for self-adaptive outbreak judgment.

Background

The solar radio data with high time resolution and high frequency resolution is beneficial to accurately and precisely measuring solar radio burst driving shock waves, high-energy electron energy, shock waves and electron arrival time, and can better provide more reliable data for solar physics research and space weather monitoring. Therefore, the time and frequency resolution is an important index for the solar radio observation system, and is an important index sought by each solar radio observation station in the world. For example, juanjuan of Wang Shu of Chinese academy of sciences adds a new super high resolution observation mode to the national astronomical table Huairo radio spectrometer, and the time resolution can be as high as 1.25ms and the frequency resolution can be 4MHz in the frequency band of 1.10-1.34GHz, and the solar radio fine structure event is observed, so that the coronage substance ejection can be related to the drifting pulse structure in lower coronage.

DU introduces an observation system for realizing solar radio by using a high-speed acquisition card in 2017, wherein the system acquires solar radio signals quantitatively at intervals, and time domain data is directly stored and analyzed off-line. However, the high-speed AD sampling rate is 1Gsps, the ADC bit number is 12 bits, 2 channels are adopted, the high-speed data flow is 4GB/s, and the PCIe speed and the hard disk speed of the computer cannot keep up with the speed. In addition, the capacity of the computer disk array is limited, and it is difficult to store all data (14.4T/H). Therefore, with the use of interval quantitative acquisition data, the reduction in the amount of data sacrifices the sensitivity of the system, which may result in a reduction in image resolution at high temporal resolution and high frequency resolution due to the reduction in the amount of data. Although the scheme of judging the outbreak event in the FPGA is adopted, the data can be densely acquired during the outbreak and sparsely acquired at other times, the FPGA is hardware operation, the capacity is limited, a complex judging algorithm is difficult to implement, the change of the solar radio signal is complex, a large number of interference signals exist in the space in practical application, the judgment of the outbreak event is greatly influenced, the storage data volume cannot be effectively reduced, the data occupy a large storage space, the service life of a disk is reduced by frequently reading and writing the deleted data for multiple times, and the huge data analysis needs a machine time, so that the effective judgment of the outbreak event and the reduction of the non-outbreak data storage volume are particularly important. The Yunnan astronomical stage adopts an 11m parabolic antenna to receive 70-700MHz solar radio signals, the time resolution reaches 2ms, the frequency resolution is 200KHz, in order to reduce the cost, an electronic switch is adopted to switch left and right polarization signals to a frequency spectrograph for collection in a time-sharing manner, so that left-handed signals are collected in one period, right-handed signals are collected in the next period, the left-handed signals are not circularly polarized synthetic signals in the same time in strict meaning, 50% of data are lost, and the sensitivity of the system is reduced by 50%.

At present, the international metric wave radio observation system with more advanced technical indexes belongs to AMATERAS developed in 2010 by Tohoku university in japan (Iwai et al, 2012). AMATERAS observed over a frequency range of 150-500MHz with time and frequency resolution up to 10ms and 61kHz (16384 spectrometer channels) can observe left and right hand polarization signals using an IPRT (ii site planar Raido Telescope) antenna system consisting of two identical rectangular parabolas of 16.5 x 31 meters. The system appears to perform well, however, the station was originally built for monitoring the Jupiter radio signals and was not specifically built for solar radio observation; the local (fukushima area) radio frequency interference is severe, which can be clearly seen from the observation data of the system; perhaps to avoid these interferences, the system can observe the lowest frequency of 150MHz, and cannot observe the highest frequency partial region of type II storm events (e.g., mine & Erickson,2005 subramanian &ebenezer, 2006), so that many burst events cannot be completely recorded.

In summary, in the prior art, an effective solution is still lacking for the problems that many outbreak events cannot be completely recorded, the outbreak events cannot be effectively judged, and the non-outbreak data storage amount cannot be reduced.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a high-resolution solar radio data processing system and method for self-adaptive outbreak judgment, all data acquired by high-speed AD are applied, namely the highest system sensitivity is kept, high-speed data flow is firstly preprocessed by FPGA (field programmable gate array), the speed of data flow transmitted to a computer is reduced, the method for judging the solar radio outbreak is realized in the computer, whether solar radio outbreak occurs or not is judged by radio flow of an interference-free frequency point, the time resolution during outbreak can reach 1ms or higher, and the frequency resolution reaches 16KHz; when the solar storm does not burst, the signals are subjected to integral accumulation processing, the time resolution is reduced to be 100ms or lower, the solar storm burst can be observed finely, and the data volume of the stored quiet solar radio signals is effectively reduced.

The technical scheme adopted by the invention is as follows:

the invention provides a high-resolution solar radio data processing system for self-adaptive outbreak judgment, which comprises a parabolic antenna, a frequency conversion card, a focal plane circuit, a high-speed ADC (analog to digital converter) collector, an FPGA (field programmable gate array) and a computer, wherein the frequency conversion card is connected with the computer;

the parabolic antenna is configured to receive a solar radio signal and output two paths of antenna signals to the frequency converter;

the frequency conversion card is configured to convert the two antenna signals into four antenna signals and transmit the four antenna signals to the focal plane circuit;

the focal plane circuit is configured to filter and amplify the antenna signal and transmit the processed signal to the high-speed ADC collector;

the high-speed ADC collector is configured to convert each path of antenna signal into a high-speed digital signal and transmit the high-speed digital signal to the FPGA;

the FPGA is configured to intercept and segment four-path high-speed digital signals according to a certain word length, perform FFT operation on each segment respectively, convert time domain solar radio signal data into frequency domain data, perform digital polarization synthesis in the frequency domain to obtain circularly polarized left-handed and right-handed solar radio signals, calculate the power of the solar radio signals, perform integral operation on the power of the solar radio signals according to time resolution to obtain solar radio frequency spectrum signals, and upload the solar radio frequency spectrum signals to a computer;

the computer is configured to perform adaptive explosion judgment on the solar radio frequency spectrum signal, store data containing solar explosion events according to high resolution, perform compression processing on the data not containing the solar explosion events, and store the data according to low resolution.

Further, the computer includes a PCIe interface, a virtual memory, a CPU, a memory, and a disk array, where data processed by the FPGA is uploaded to the virtual memory of the computer through the PCIe interface, the CPU of the computer detects whether a new data packet is generated in the virtual memory, and if a new data packet is generated in the virtual memory, reads an old data packet stored in the virtual memory into the memory, performs adaptive burst determination and processing, stores the processed data packet in the disk array, and deletes the data packet in the virtual memory.

Further, the focal plane circuit includes an amplifying circuit and a filtering circuit.

The second purpose of the invention is to provide a high-resolution solar radio data processing method for self-adaptive outbreak judgment, which comprises the following steps:

initializing, setting a compressed frame number and a solar burst amplitude;

collecting solar radio data, preprocessing the solar radio data to obtain solar radio frequency spectrum data, and forming a data packet;

detecting whether a new data packet is generated;

when detecting that a new data packet is generated, carrying out self-adaptive outbreak judgment on an old data packet;

if the old data packet has a solar burst event, storing the data packet to a disk array according to high time resolution;

and if the solar burst event does not exist in the old data packet, compressing the data according to the compressed frame number, and storing the compressed data packet into the disk array according to the low time resolution.

Further, the step of preprocessing the solar radio data comprises:

amplifying and filtering the solar radio data, and converting the solar radio data into a high-speed digital data stream;

the method comprises the steps of intercepting and dividing a high-speed digital data stream into a plurality of sections according to a certain word length, performing FFT (fast Fourier transform) operation on each section, converting time domain solar radio data into frequency domain data, performing digital polarization synthesis in a frequency domain to obtain circularly polarized left-handed and right-handed solar radio data, calculating the power of the solar radio data, and performing integral operation on the power of the solar radio data according to time resolution to obtain solar radio spectrum data.

Further, the method for detecting whether a new data packet is generated includes:

storing a data packet containing solar radio frequency spectrum data into a virtual memory disc of a computer;

the computer continuously detects whether a new data packet is generated in the virtual memory disk;

if the virtual memory disk has a new data packet, the computer reads the old data packet stored in the virtual memory disk into the memory, performs adaptive burst judgment and processing, stores the processed data packet into the disk array, and deletes the data packet stored in the virtual memory disk.

Further, the adaptive burst determination method includes:

analyzing the frequency spectrum of the solar radio frequency spectrum data packet, and averagely selecting a plurality of interference-free frequency points from the measurement frequency band according to a certain interval;

calculating the solar radio flow of all the selected frequency points;

comparing the difference of the solar radio current quantity of all the frequency points at intervals of a certain time with the solar burst amplitude;

if the difference value of the two frames before and after the solar radio flow of the frequency point exceeds the set solar burst amplitude value, judging that the data of the frequency point contains a solar burst event, calculating the average value of the two frames of solar radio flow of the frequency point, and taking the average value as the solar burst threshold value of the frequency point;

and in the subsequent time period, if the solar radio current value of the frequency point exceeds the set solar explosion threshold, judging that the data of the frequency point contains an explosion event.

Further, in all the selected frequency points, if the radio flow of one of the frequency points is greater than the set solar explosion threshold, the judgment is immediately stopped, the data packet is explosion data, the data packet is completely stored in the disk array disk, and the data packet in the virtual memory disk is deleted.

Further, if the radio flow values of all the frequency points selected from the data packet are smaller than the solar burst threshold, the data packet does not contain a solar radio burst event, the data is compressed, the data of each set frame number is added and averaged to obtain a new compressed data packet, and the new data packet is written into the disk array.

Compared with the prior art, the invention has the beneficial effects that:

(1) The invention utilizes the high-speed ADC to collect data, the high-speed data stream is preprocessed through the FPGA, the speed of the data stream transmitted to the computer is reduced, and the computer judges the solar radio outbreak, so that the outbreak event can be effectively judged;

(2) The invention judges whether the solar radio is exploded or not through the radio flow of the interference frequency point, the time resolution can reach 1ms or higher during explosion, and the frequency resolution reaches 16KHz; when the solar radiation signal does not explode, the signal is subjected to integral accumulation processing, the time resolution is reduced to 100ms or lower, a plurality of explosion events can be completely recorded, and the data volume of the stored quiet solar radiation signal is effectively reduced;

(3) The invention is uploaded to a computer through a PCIe interface, the computer judges the multi-frequency point solar radio flow, stores the data containing the solar burst events according to high resolution, and performs accumulation operation on the data not containing the solar burst events to reduce the time resolution and reduce the non-burst data storage capacity.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

FIG. 1 is a block diagram of a high resolution solar radio data processing system with adaptive burst determination;

FIG. 2 is a block diagram of the internal structure of a computer;

FIG. 3 is a flow chart of a high resolution solar radio data processing method for adaptive flare determination;

FIG. 4 (a) is a graph of a solar radio burst event;

FIG. 4 (b) is a graph of radio current corresponding to the 150-500MHz band;

FIG. 5 is a change curve diagram of radio flow of different frequency points of solar radio in 2017-9-9 days;

FIG. 6 (a) is a graph of 017-9-9 days solar radio burst events;

FIG. 6 (b) is a graph showing the change of radio flow at different frequency points in solar radio of 2017-9-26 days;

FIG. 7 is a graph of outbreak events observed by the new system at 9/26 months in 2017;

FIG. 7 (a) is a 100ms temporal resolution image;

FIG. 7 (b) is a 10ms temporal resolution image;

FIG. 7 (c) is a 1ms temporal resolution image;

FIG. 7 (d) is a 0.1ms temporal resolution image;

FIG. 8 is a graph of the outbreak observed by the quantitative acquisition system for the 26-day cycle of 9 and 9-2017;

FIG. 8 (a) is a 10ms time resolution solar radio dynamic spectrum plot;

FIG. 8 (b) is a 1ms time resolution solar radio dynamic spectrum plot;

FIG. 9 is a detailed view of a high frequency resolution dynamic spectrogram;

FIG. 9 (a) is an intensity plot (100 ms) for the 160-170MHz band;

FIG. 9 (b) is an intensity plot (10 ms) for the 160-170MHz band;

FIG. 9 (c) is an intensity plot (100 ms) for the 200-210MHz band;

FIG. 9 (d) is a graph of the intensity (10 ms) for the 200-210MHz band;

FIG. 10 is a detailed view of the high frequency resolution dynamic spectrum of the spaced quantitative acquisition system;

FIG. 10 (a) is a 160-170MHz dynamic spectrum plot (100 ms);

FIG. 10 (b) is a 160-170MHz dynamic spectrum diagram (10 ms).

Detailed Description

The invention is further described with reference to the following figures and examples.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

As described in the background art, the prior art has the defects that an outbreak event cannot be effectively judged, the non-outbreak data storage amount is reduced, and a partial area with the highest outbreak frequency cannot be observed, so that a plurality of outbreak events cannot be completely recorded.

Example 1:

in an exemplary embodiment of the present application, as shown in fig. 1, a high-resolution solar radio data processing system for adaptive outbreak judgment is provided, which includes a parabolic antenna, a computer, a high-speed data acquisition card and a frequency conversion card; the high-speed data acquisition card and the frequency conversion card adopt a PCIe card structure, the high-speed data acquisition card consists of an FMC daughter card and an FMC mother card, and the FMC daughter card carries chips such as an ADC (analog-to-digital converter), a clock chip and a balun and is responsible for high-speed data acquisition; the FMC mother card carries chips such as an FPGA, a DDR, a PROM and the like and is responsible for high-speed signal processing; the main modules realized inside the FPGA are as follows: FIFO module, FFT module, FIR filter, mixer (multiplier), NCO module, PCIe module, MIG module, etc.

The parabolic antenna is configured to receive a 150-500MHz solar radio signal and mechanically track the sun track, and is a log periodic array antenna and outputs two paths of signals, wherein one path of signals is a horizontal antenna signal, and the other path of signals is a vertical antenna signal.

The frequency conversion card is configured to divide each antenna signal into 2 segments, 150-325MHz and 325-500MHz, and obtain four antenna signals.

Because the sampling rate of the high-speed ADC collector is small, the frequency of 150-500MHz cannot be directly collected, therefore, a frequency conversion card is adopted to divide the signal into two sections, then the two sections of signals are simultaneously up-converted to 875M intermediate frequency, and the two sections of signals are simultaneously collected by the high-speed ADC collector.

The focal plane circuit is configured to perform front-end amplification and filtering processing on the four antenna signals, and transmit the processed signals to the ADC collector.

Specifically, the focal plane circuit includes an amplifying circuit and a filtering circuit.

And the high-speed ADC collector is configured to convert the four paths of signals subjected to front-end amplification and filtering into high-speed digital signals and transmit the high-speed digital signals to the FPGA.

In this embodiment, the high-speed ADC collector adopts a 500Msps sampling rate and a 14bit high-speed ADC collector.

The FPGA is configured to perform FFT operation on the four-path high-speed data signals, perform digital polarization synthesis in a frequency domain, perform data processing to obtain a solar radio frequency spectrum signal with 1 ms-level time resolution (16 KHz frequency resolution), and upload the solar radio frequency spectrum signal to a computer through a PCIe interface.

Specifically, the four high-speed data signals are cut and segmented by the FPGA according to the word length of FFT operation, the FPGA carries out FFT operation on each segment, time domain solar radio signal data are converted into frequency domain data, digital polarization synthesis is carried out in the frequency domain, circularly polarized left-handed and right-handed solar radio signals are obtained, the power of the solar radio signals is calculated, integral operation is carried out on the power of the solar radio signals according to time resolution, solar radio spectrum data are obtained, and the sun radio spectrum data are uploaded to a computer with a timestamp.

In this embodiment, the FPGA segments the high-speed data signal according to a 32K word length, and performs cumulative addition operation on the power of the solar radio signal according to the time resolution, thereby reducing the data size.

The computer is configured to judge the multi-frequency point solar radio flow, store the data containing the solar burst events according to high resolution, and perform accumulation operation on the data not containing the solar burst events to reduce the time resolution and reduce the data volume of the events.

Specifically, the data processed by the FPGA is uploaded to a virtual memory disk of the computer through a PCIe interface, and a 32GB memory virtual memory disk is used as a data cache region through Primo Ramdisk software by using a virtual memory technology. After the FPGA carries out 32K-point FFT on 4 paths of signals to generate power signals, each path of signals is 32KB, the total is 128KB, accumulated summation operation (for example, the maximum 1ms is taken as the resolution) is carried out on the power signals in the time resolution, the result is uploaded to a computer through PCIe, the data flow speed is 128MB/s, the generated data is about 460GB in 1 hour, the observation time is 12 hours every day, the data is about 5.4TB, obviously, the disk array of dozens of TB can only store dozens of days of data, and the long-term observation requirement is not facilitated. And in the data, the solar burst data for high-resolution research is little, a large amount of quiet solar radio signal data is basically unchanged, high-resolution data is not needed, and if the quiet solar radio high-time resolution data needs to be researched, the time resolution can be changed at any time to acquire and store the solar radio data.

The computer further processes the uploaded data, and distinguishes solar radio burst from non-burst signals, wherein during burst, the data is stored according to the highest time resolution of 1ms and is about 128MB/s, and during non-burst, the data is stored according to the time resolution of 100ms and is about 1.28MB/s, namely the data volume of about 4.6GB in 1 hour, so that the data storage volume is effectively reduced. The data processing structure block diagram of the computer is shown in fig. 2.

The embodiment of the invention provides a high-resolution solar radio data processing system capable of self-adaptive outbreak judgment, which adopts a parabolic antenna to receive solar radio signals, digitalizes the solar radio signals by high-speed AD, performs FFT operation by an FPGA, performs digital polarization synthesis in a frequency domain, performs data processing to obtain solar radio frequency spectrum signals with 1 ms-level time resolution (16 KHz frequency resolution), uploads the solar radio frequency spectrum signals to a computer through a PCIe interface, and judges multi-frequency point solar radio flow by the computer.

Example 2:

another exemplary embodiment of the present application, as shown in fig. 3, provides a high resolution solar radiation data processing method with adaptive burst determination.

(1) And analyzing the interference factors of the solar radio current.

In order to effectively reduce the data storage capacity, whether the data contains the solar burst event or not is judged. When the sun bursts, the solar radio flow can be obviously increased and tends to be gentle when the sun calms, so that the solar radio flow parameters can be used for judging the solar burst event. Due to the fact that a large amount of interference exists in the space, such as radio station signals, noise interference and the like, the interference can cause pulse interference and periodic interference to appear in data, the change of the magnitude of solar radio flow is affected, and the change affects the accuracy of solar burst judgment. The solar energy flux is also fluctuating, as shown in fig. 4 (a) for solar energy burst; fig. 4 (b) is a curve of the change of the solar radio flux (total radio flux in the 150-500MHz band) during solar radio burst, in which the ordinate value is the power value and is calculated as the system measurement value, P = (D/32768 × 0.8) 2 (D is the system measurement value), the relative quantity provisional unit is 1, and the system can be converted to SFU after calibration, which requires a coefficient conversion. It can be seen from the solar radio flow change diagram that the solar radio flow is increasing during solar burst, but when the solar radio does not burst, the radio flow also has sudden sharp change, and it is obviously difficult to accurately judge the solar burst only by the total solar radio flow.

The solar radio dynamic spectrum data is researched and analyzed, radio flow charts of all frequency points are respectively drawn and compared, as shown in fig. 5, radio flow of 4 frequency points of a solar radio outbreak event in fig. 4 (b) is counted, and as shown in fig. 5, it can be seen that the radio flow of the 262MHz frequency point has large fluctuation, while the other 3 frequency points have small fluctuation of 195MHz, 205Mhz and 218MHz, and the solar radio flow is obviously increased only when the sun breaks out. As can be seen from the dynamic spectrogram of the burst event in fig. 4 (b), there is an interfering station on the 262MHz frequency point, and there is no interfering station signal on the other 3 frequency points. Further, as shown in fig. 6 (a) and 6 (b), the outbreak event was analyzed for 9/26/2017, and the same results were obtained even when there was no outbreak event. Obviously, the fluctuation of the solar radio current is mainly caused by radio station interference, and particularly, the radio station is pulsed and the interference is stronger.

Therefore, the station interference signal is a solar radio current interference factor.

(2) The high-resolution solar radio data processing method based on self-adaptive outbreak judgment specifically comprises the following steps of:

step 201: initializing, setting the number of compressed frames and judging the solar burst amplitude for the first time.

The number of the compressed frames is set to be one hundred, if the data packet does not contain a solar radio burst event, the data is processed, the data of each hundred frames are added and averaged to form one frame, the time resolution of a newly generated data packet is reduced by 100 times, namely 100ms, the size of the newly generated data packet is reduced by one hundred times, and then the new data packet is written into the disk array, so that the amount of calm solar data is effectively reduced.

And the set solar burst amplitude is used for judging the solar burst event.

Step 202: and collecting solar radio data, and preprocessing the solar radio data to obtain solar radio frequency spectrum data.

The solar radio data of 150-500MHz are received by a 6m parabolic antenna, collected by a high-speed data acquisition card and preprocessed.

Specifically, a high-speed ADC collector on the high-speed data acquisition card converts solar radio data into a high-speed digital data stream, the converted high-speed digital data stream is preprocessed by an FPGA on the high-speed data acquisition card, the FPGA intercepts and divides the high-speed digital data stream into a plurality of sections according to the word length of 32K, the FPGA performs FFT operation on each section respectively, time-domain solar radio data is converted into frequency-domain data, digital polarization synthesis is performed in a frequency domain to obtain circularly polarized left-handed and right-handed solar radio data, the power of the solar radio data is calculated, the power of the solar radio data is cumulatively added according to time resolution to obtain solar radio spectrum data, and the solar radio spectrum data are uploaded to a virtual memory disc of a computer through a PCIe interface.

Step 203: and detecting whether a new data packet is generated.

The high-speed data is temporarily stored in the virtual memory disk of the computer, the data packet is judged whether to be burst data or not, corresponding processing is respectively carried out, the data can be processed in real time only by judging whether to burst or not and judging the time for processing the data to be less than the time for generating the high-speed data, and a large amount of time is occupied by reading and writing the data in the virtual memory disk by utilizing the high-speed transmission speed of the memory, so that the reading and writing time can be greatly reduced.

The test speed of data transmission between the virtual memory disk and the memory is 3.5GB/s, and the requirement of high-speed processing can be met. The data is read from the virtual memory disk to the memory, the data is judged and processed, the data speed of the processed data is reduced, and the processed data can be directly stored in the disk array.

Specifically, data acquired at a high speed is continuously uploaded to a virtual memory disc of a computer, the computer continuously detects whether a new data packet is generated in the virtual memory disc, a buffer data packet always exists in the virtual memory disc and is marked as an nth data packet, and when a new data packet is generated, namely an n +1 th data packet is transmitted to the virtual memory disc of the computer, the computer starts to process the nth data packet, so that the integrity of the data packet can be ensured, the parallel transmission and processing can be realized, the transmission time of the data packet is better hidden, and the operation speed is further improved; and deleting the nth data packet after the nth data packet is processed, and starting to process the (n + 1) th data packet until the new data packet is generated and transmitted to a virtual memory disc of the computer, so that the speed of processing the data packet by the system is higher than the speed of generating the new data packet to realize real-time processing.

Step 204: and (4) judging the self-adaptive outbreak of the multi-frequency-point solar radio flow.

It can be known from the above that the factor of interference to the solar radio flow is mainly caused by the radio station interference signal, and in order to accurately judge the solar radio outbreak event, it is feasible to adopt the change of the solar radio flow of the frequency point without the radio station interference as the basis. The frequency range corresponding to the solar radio outbreak is not fixed, therefore, the frequency spectrum of the received solar radio frequency spectrum data is analyzed according to the position of the receiver, the frequency band of an interference radio station is avoided, 20 frequency points without interference are extracted from the measuring frequency band of 150 MHz-500 MHz, one frequency point is extracted at an average interval of 17.5MHz, and when the frequency point of the radio station is met, the frequency point is properly deviated. The method can better cover the signals of the measuring frequency range, avoid missing the outbreak event in the smaller frequency range, avoid the frequency range with more interference and reduce the judgment processing time.

As can be seen from fig. 5 and fig. 6 (b), at the frequency point with less interference, the curve fluctuation is smaller when the sun is calm, and the curve change is more obvious during the outbreak, which is beneficial to the judgment.

And calculating and counting the radio flow of the selected frequency point, and finding that the quiet solar radio flow has slight change in different time periods when no outbreak occurs. According to the data of the Space Weather Services website, the solar radio data with 245MHz frequency points, which are not exploded for some time since 2013, are randomly extracted and counted, and as shown in Table 1, the same conclusion can be obtained, although the quiet solar radio can change for a long time, the change range is smaller in a shorter time, and is much smaller than the explosion change.

TABLE 1 2454mhz frequency point quiet solar radio flow

Through observing historical data, the solar burst initiation stage, the radio current volume begins to increase, when the increase value exceeds a set value at certain time intervals, an outbreak event is considered to occur, the set value is determined as a solar burst amplitude value, and the solar burst amplitude value can be set through a system and used for judging the solar burst event.

The solar radio outbreak usually lasts for more than 1S, and in order to reduce the calculation amount, the system carries out comparison and judgment once at an interval of 500ms, so that the solar outbreak event in a short time can be effectively judged, and the phenomenon that the processing speed is influenced by too many judgment times due to too short interval time is avoided. The interval time may also be set to 100ms.

When the difference value of the solar radio flow of two frames at the frequency point interval of 500ms exceeds the set solar explosion amplitude, judging that the data contains an explosion event, averaging the values of the two frames, and setting the average value as the solar explosion threshold of the frequency point for judging the next explosion event. Each frequency point can be provided with an independent solar explosion threshold, and as long as the solar radio current value of one frequency point exceeds the set threshold, the data of the frequency point is judged to contain an explosion event, and the data of the data packet is stored according to the highest time resolution. And when the solar burst is finished, the radio current flow parameter is reduced and tends to be stable, and the collected data is lower than the solar burst threshold and is judged to be non-burst data. The method can adapt to the unstable situation of the calm solar radio current at different time, the outbreak threshold value is reset every day, and the outbreak threshold value is automatically set when outbreak occurs.

However, when the sun is in continuous outbreak, the radio flow is stable at a high value for a long time, the fluctuation of the value does not exceed the set solar outbreak amplitude, if the situation that the sun continuously bursts at the beginning of collection occurs, the method is difficult to judge, in order to avoid the extreme situation, the invention sets a high fixed threshold value for the radio flow of each frequency point to assist judgment, and when the value of the solar radio flow exceeds the fixed threshold value, the current data is considered to contain an outbreak event.

Specifically, after a new data packet is detected to be uploaded in the virtual memory disc, the system reads 20 designated frequency point data in the data packet every 500 frames from the data packet, and judges according to the method, if the radio flow of one of the selected 20 frequency points is greater than a set solar explosion threshold, the judgment is immediately stopped, the data packet is explosion data, the data packet is completely stored in the disk array disc, and the data packet in the virtual memory disc is deleted; if the radio flow values of all frequency points extracted from the data packet are smaller than the solar burst threshold, the data packet does not contain a solar radio burst event, the data is processed, data of each hundred frames are added to average to form one frame, the time resolution of the newly generated data packet is reduced by 100 times, namely 100ms, the size of the newly generated data packet is reduced by one hundred times, and then the new data packet is written into the disk array, so that the amount of calm solar data is effectively reduced.

The non-explosive data are processed, and the explosive data are kept at high time resolution, so that the solar radio explosion is observed under high time resolution, the data amount of quiet solar time is reduced, the disk space is saved, the data containing explosive events can be more intuitively distinguished in later data analysis, and the analysis time is reduced.

The embodiment of the invention provides a high-resolution solar radio data processing method for self-adaptive outbreak judgment, which is characterized in that all data acquired by high-speed AD (analog-to-digital) are applied, namely the highest system sensitivity is kept, high-speed data flow is preprocessed by an FPGA (field programmable gate array), the speed of data flow transmitted to a computer is reduced, a method for judging solar radio outbreak is realized in the computer, whether solar radio outbreak occurs or not is judged through radio flow of interference-free frequency points, the time resolution during outbreak can reach 1ms or higher, and the frequency resolution reaches 16KHz; when the solar storm happens, the signals are subjected to integral accumulation processing, the time resolution is reduced to be 100ms or lower, the solar storm outbreak can be observed finely, and the data volume of the stored quiet solar radio signals is effectively reduced.

The method can adapt to the unstable conditions of quiet solar radio flow at different time, automatically set a solar burst threshold, and automatically trigger different processing on the solar radio data according to whether the solar radio data burst or not, if the radio flow of one of the frequency points is greater than the set solar burst threshold in all the selected frequency points, immediately stop judging, wherein the data packet is burst data, completely store the data packet into a disk array disk, and delete the data packet in a virtual memory disk; and if the radio flow values of all the frequency points selected from the data packet are smaller than the solar burst threshold, the data packet does not contain a solar radio burst event, the data is compressed, the data of each set frame number are added and averaged to obtain a new compressed data packet, and the new data packet is written into the disk array.

Example 3:

a specific application example is listed below.

After the test, the system starts test operation at the racking observation station. In order to compare with the data of the original interval quantitative sampling scheme, after the antenna signals are amplified and filtered, the power divider is respectively connected into 2 systems to carry out simultaneous acquisition and receiving work. Fig. 7 is a solar radio dynamic spectrum diagram observed by an observation system new in 2017, 9, 26 and a day, in which the outline part in fig. 7 (a) is a recognized burst event, the area data is 1ms resolution, and the other surrounding 100ms resolution, in order to further analyze the event, high time resolution analysis can be performed in the outline, and in order to analyze the solar radio change before and after the burst event by adopting high time resolution, the system is improved, and how long the data with high time resolution can be stored before and after setting. Fig. 7 (b) is a 10ms dynamic spectrum diagram, and fig. 7 (c) and 7 (d) are dynamic spectrum diagrams of 1ms partial positions. The difference of the definition of the dynamic spectrogram under different time resolutions can be seen from the graph, and the subtle change in the solar burst process can be clearly seen from the dynamic spectrogram with the highest time resolution of 1ms, so that the requirement of high time resolution analysis is met.

For the purpose of comparing and explaining the problems, signals received by the interval quantitative acquisition receiving system are drawn into the same dynamic spectrogram for the solar radio in the same time period according to the same time resolution. Fig. 8 (a) and 8 (b) correspond to fig. 9 (b) and 9 (c), respectively, and the time resolution is the same, so that it can be seen that the solar radio dynamic spectrograms of fig. 8 (a) and 8 (b) are obviously unclear, the detail resolution is coarse, the significance is obviously reduced, and mainly, the interval quantitative acquisition system loses a large amount of data.

The frequency resolution of the system is determined by the ADC sampling rate and the FFT operation point number of the system, the sampling rate is 500msps, the FFT point number is 32K, and the frequency resolution is 16KHz. In order to observe the details of the change of the frequency of the sun spot, the frequency band of interest can be expanded. In order to maintain a certain sensitivity, the time resolution is reduced at high frequency resolution. Fig. 9 is a comparison of solar radio signals in the same frequency range and different time resolutions, fig. 9 (a) and 9 (b) are dynamic spectrograms of 160-170MHz frequency band at 100ms and 10ms time resolution, respectively, and fig. 9 (c) and 9 (d) are dynamic spectrograms of 200-210MHz frequency band at 100ms and 10ms time resolution. It can be seen that fig. 9 (a) and 9 (c) are clearer due to the lower time resolution, and the details of the frequency variation, i.e. the details of the dynamic spectrogram with clearer frequency resolution, and the time resolution is reduced. By observing different time resolution and frequency regions, various solar radio fine structures can be clearly observed according to requirements.

Fig. 10 is an analysis of observation data of the interval quantitative collection system, and it can also be seen that fig. 10 (a) and fig. 10 (b) correspond to fig. 9 (a) and fig. 9 (b), respectively, and the significance of the dynamic spectrum diagram of fig. 10 is significantly lower than that of fig. 10.

The invention realizes the judgment of whether the solar radio signal is exploded or not, can adapt to the unstable conditions of quiet solar radio flow at different time, automatically sets the solar explosion threshold and solves the problem of insensitive judgment by adopting a fixed threshold. The solar radiation data are automatically triggered to be processed differently according to whether the solar radiation data explode or not, the data are stored according to the high time resolution of 1ms during explosion, the solar radiation storm is conveniently researched, the fine structure under the high time resolution is analyzed, and understanding of the solar flare and the solar corona substance ejection (CME) process and the dynamic process of the solar flare and the solar corona substance ejection (CME) process are facilitated; when the solar radiation signal does not burst, the data is stored according to the low time resolution of 100ms, the data storage amount is reduced, and the data is stored as historical data so as to research the long-term change rule of the solar radiation signal. Through experimental comparison, the scheme fully utilizes the received solar radio signals, and the sensitivity is higher than that of a solar radio dynamic spectrogram obtained by an interval quantitative sampling system.

The resolution of the present invention can be further improved, and in order to maintain the corresponding resolution, if the time resolution is improved, the frequency resolution needs to be reduced. The invention carries out 32K word length FFT operation on the solar radio signal, the frequency resolution is 16KHz, the highest time resolution reaches 1ms, if the FFT operation word length is reduced, the frequency resolution is reduced, for example, 3.2K word length FFT operation, when the frequency resolution is 160KHz, the time resolution of 0.1ms can be realized by the system under the condition of the same data volume.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.

Claims

1. A high-resolution solar radio data processing system capable of judging self-adaptive outbreak is characterized by comprising a parabolic antenna, a frequency conversion card, a focal plane circuit, a high-speed ADC (analog to digital converter) collector, an FPGA (field programmable gate array) and a computer;

the computer is configured to perform adaptive burst judgment on the solar radio frequency spectrum signal, store data containing solar burst events according to high resolution, perform compression processing on the data not containing the solar burst events, and store the data according to low resolution.

2. The system for processing high-resolution solar radio data according to claim 1, wherein the computer includes a PCIe interface, a virtual memory disk, a CPU, a memory, and a disk array, data processed by the FPGA is uploaded to the virtual memory disk of the computer through the PCIe interface, the CPU of the computer detects whether a new data packet is generated in the virtual memory disk, and if a new data packet is generated in the virtual memory disk, reads an old data packet stored in the virtual memory disk into the memory, performs adaptive burst determination and processing, stores the processed data packet in the disk array, and deletes the data packet in the virtual memory disk.

3. The adaptive burst aware high resolution solar radio data processing system according to claim 1, wherein the focal plane circuit comprises an amplification circuit and a filtering circuit.

4. A high-resolution solar radio data processing method for self-adaptive outbreak judgment is characterized by comprising the following steps:

initializing, and setting a compressed frame number and a solar burst amplitude;

detecting whether a new data packet is generated;

if the solar burst event does not exist in the old data packet, compressing the data according to the number of the compressed frames, and storing the compressed data packet into the disk array according to the low time resolution.

5. The method of adaptive burst aware high resolution solar radio data processing according to claim 4 wherein the step of preprocessing the solar radio data comprises:

6. The method for processing high-resolution solar radioelectric data for adaptive outbreak judgment according to claim 4, wherein said method for detecting whether a new packet is generated comprises:

storing the data packet containing the solar radio frequency spectrum data into a virtual memory disk of the computer;

7. The method for high-resolution solar radioelectric data processing with adaptive outbreak determination according to claim 4, wherein the adaptive outbreak determination method is:

calculating the solar radio flow of all the selected frequency points;

comparing the difference of the solar radio flow of all the frequency points at intervals of a certain time with the solar burst amplitude;

8. The method for processing high-resolution solar radio data with adaptive burst judgment according to claim 7, wherein in all the selected frequency points, if the radio flow of one of the frequency points is greater than the set solar burst threshold, the judgment is immediately stopped, the data packet is burst data, the data packet is completely stored in the disk array disk, and the data packet in the virtual memory disk is deleted.

9. The method for processing high-resolution solar radio data with adaptive burst judgment according to claim 7, wherein if the radio flow values of all the frequency points selected from the data packet are smaller than a solar burst threshold, the data packet does not contain a solar radio burst event, the data is compressed, the data of each set frame number is added and averaged to obtain a new compressed data packet, and the new data packet is written into the disk array.