CN116318498A - Digital correlation system and synchronization method for radio-solar imager - Google Patents
Digital correlation system and synchronization method for radio-solar imager Download PDFInfo
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Abstract
The invention relates to the technical field of radio astronomical signal acquisition and processing, in particular to a radio day image instrument digital correlation system and a synchronization method. The digital correlation system of the day imager receives time signals through the time signal receiving module, decodes the time signals to obtain absolute time information, and respectively sends the absolute time information to the display control unit module, the signal acquisition processing module and the storage server module; the display control unit module is used for issuing delay compensation parameters to the signal acquisition processing module according to the absolute time information, and issuing starting and stopping control instructions to the signal acquisition processing module and the storage server module; the signal acquisition processing module is used for acquiring and processing analog signals, determining corresponding delay compensation parameters according to absolute time information, and adopting the corresponding delay compensation parameters to carry out delay compensation on acquisition channels corresponding to the signal acquisition processing module so as to ensure accurate operation of the digital receiving system of the day image instrument.
Description
Technical Field
The invention relates to the technical field of radio astronomical signal acquisition and processing, in particular to a radio day imager digital receiving related system and a synchronization method.
Background
The solar imager is used for detecting and researching the nature and law of solar activity, revealing the action and influence mechanism of solar activity on the space environment of the sun and the earth, and guaranteeing the living and developing environment of human beings to the greatest extent. To observe the sun by radio imaging, the most common technique is synthetic aperture interference imaging. The synthetic aperture imaging technology is a method for combining a plurality of telescopes with smaller caliber into a large telescope and utilizing the Fourier transformation principle to image correctly. An observation array composed of radio telescope based on synthetic aperture interference imaging generally comprises: the system comprises an antenna front end, a signal transmission line, an analog signal receiving unit, a digital correlation system and an image synthesis processing unit. And the digital correlation system of the solar imager carries out full correlation operation on all channels in a spatial frequency domain to obtain the distribution of the visibility function in the spatial frequency domain. The space brightness distribution and the visibility function are Fourier transform pairs, and the rear-end image processing unit can obtain a solar radio image by carrying out Fourier transform on the visibility function.
In order to obtain accurate solar radio images, synchronization of the total system of the solar imager is important. Synchronization of radio day imager digital correlation systems is embodied in three aspects: firstly, signal acquisition is synchronous. Because the phase of the correlation operation result contains the phase of the visibility function, according to the signal processing correlation theory, the time delay of the time domain corresponds to the phase difference of the frequency domain, so that the strict synchronization of the signal sampling of different channels needs to be ensured; and secondly, delay compensation synchronization. Because the earth rotates, the distance between the antenna and the sun changes along with time, the solar radiation signal has different time delays from the antenna to different moments, so that the phase of the correlation function changes along with time, and a time-varying delay compensation is needed to be added to a digital correlation system and used for counteracting the rapid time variation of the correlation function caused by geometric time delay; thirdly, data storage synchronization. Because the image processing unit at the back end needs to recalibrate the data according to the time information acquired by the data to obtain an accurate sun image, the data stored by the digital correlation system needs to contain accurate time information.
In practical engineering, a digital correlation system often has a plurality of modules, and different modules have different requirements on synchronization precision, so that a high-efficiency and flexible time synchronization method is needed.
Disclosure of Invention
The invention provides a radio day imager digital correlation system which is used for providing precisely synchronous time signals for a plurality of modules of the digital correlation system.
The invention provides a radio day image instrument digital correlation system, which comprises: the time service signal receiving module, the display control unit module, the signal acquisition processing module and the storage server module;
the time service signal receiving module is used for receiving time service signals, decoding the time service signals to obtain absolute time information, and respectively sending the absolute time information to the display control unit module, the signal acquisition processing module and the storage server module;
the display control unit module is used for issuing delay compensation parameters to the signal acquisition processing module according to the absolute time information, and issuing starting and stopping control instructions to the signal acquisition processing module and the storage server module;
the signal acquisition processing module is used for acquiring and processing analog signals, determining corresponding delay compensation parameters according to the absolute time information, and adopting the corresponding delay compensation parameters to carry out delay compensation on acquisition channels corresponding to the signal acquisition processing module;
the storage server module is used for storing the data output by the signal acquisition processing module according to the absolute time information.
According to the digital correlation system of the radio day imager provided by the invention, the time service signal receiving module is further used for packaging the absolute time information into a UART protocol data packet, generating a second pulse signal at the same time, and sending the UART protocol data packet and the second pulse signal to the signal acquisition processing module;
the signal acquisition processing module is further configured to determine the absolute time information according to the second pulse signal and the UART protocol data packet, determine a corresponding delay compensation parameter according to the absolute time information, and perform delay compensation on an acquisition channel corresponding to the signal acquisition processing module by adopting the corresponding delay compensation parameter.
The digital correlation system of the radio day imager provided by the invention further comprises a clock and trigger signal distribution module;
the time service signal receiving module is also used for generating a reference time frequency signal and sending the reference time frequency signal to the clock and trigger signal distribution module; the clock and trigger signal distribution module is used for generating a sampling clock signal according to the reference time frequency signal and distributing the sampling clock signal to each board card of the signal acquisition processing module; the clock and trigger signal distribution module is also used for receiving the trigger signals of the signal acquisition and processing module, distributing the trigger signals into multiple paths and respectively sending the trigger signals to each board card of the signal acquisition and processing module.
According to the radio day imager digital correlation system provided by the invention, the time service signal receiving module is further used for converting the absolute time information into a time signal of an NTP protocol before sending the absolute time information to the display control unit module and the storage server module, and then respectively sending the time signal of the NTP protocol to the display control unit module and the storage server module; the display control unit module and the storage server module are used for analyzing the time signal of the NTP protocol to obtain the absolute time information.
According to the digital correlation system of the radio day imager provided by the invention, the display control unit module is further used for continuously monitoring the absolute time information and issuing the delay compensation parameter to the signal acquisition processing module before reaching the preset starting time.
According to the digital correlation system of the radio day imager provided by the invention, the display control unit module is also used for continuously monitoring the absolute time information and updating the delay compensation parameter when reaching a preset time point.
According to the radio day imager digital correlation system provided by the invention, the signal acquisition processing module is also used for storing delay compensation parameters in a preset time period in a ping-pong buffer mode.
According to the radio day imager digital correlation system provided by the invention, the storage server module is also used for continuously monitoring the absolute time information, storing the data output by the signal acquisition processing module when the preset storage starting time is reached, and adding the time information of the current moment to the stored file in the process of storing the data;
the display control unit module is also used for continuously monitoring the absolute time information, and when the absolute time information reaches the set stop time, a stop instruction is issued to the signal acquisition processing module, and the updating of the delay compensation parameter is stopped;
and the signal acquisition processing module is also used for resetting after finishing the current data packet transmission after receiving the stop instruction.
The invention provides a radio day imager digital correlation system, wherein a signal acquisition processing module comprises a time analysis module, a digital-to-analog conversion module, a Fourier transform module, a delay compensation module, a complex correlation module and a data encapsulation module;
the digital-to-analog conversion module is used for carrying out digital-to-analog conversion on the received signals; the Fourier transform module is used for carrying out Fourier transform operation on the data after digital-to-analog conversion; the time analysis module is used for analyzing the second pulse signal and the UART protocol data packet sent by the time service signal receiving module to obtain the absolute time information;
the delay compensation module is used for determining corresponding delay compensation parameters according to the absolute time information, and adopting the corresponding delay compensation parameters to carry out delay compensation on the acquisition channels corresponding to the signal acquisition processing module; meanwhile, the method is also used for storing the delay compensation parameters in a ping-pong cache mode; the complex correlation module is used for carrying out pairwise complex correlation operation on the input data of each channel;
the data packaging module is used for packaging the output data of the complex correlation module and the current time information according to a preset format.
On the other hand, the invention also provides a synchronization method of the radio day imager digital correlation system, wherein the day imager digital correlation system comprises the following steps: the time service signal receiving module, the display control unit module, the signal acquisition processing module and the storage server module;
the synchronization method comprises the following steps:
the time service signal receiving module receives a time service signal, decodes the time service signal to obtain absolute time information, and respectively sends the absolute time information to the display control unit module, the signal acquisition processing module and the storage server module;
the display control unit module transmits delay compensation parameters to the signal acquisition processing module according to the absolute time information, and transmits start and stop control instructions to the signal acquisition processing module and the storage server module;
the signal acquisition processing module acquires and processes the analog signal, and determines corresponding delay compensation parameters according to the absolute time information, and adopts the corresponding delay compensation parameters to perform delay compensation on an acquisition channel corresponding to the signal acquisition processing module;
and the storage server module stores the data output by the signal acquisition processing module according to the absolute time information.
According to the radio day imager digital correlation system provided by the invention, the display control unit module is further used for continuously monitoring the absolute time information, and when the set stop time is reached, a stop instruction is issued to the signal acquisition processing module, and the updating of the delay compensation parameter is stopped; the signal acquisition processing module is also used for resetting after completing the transmission of the current data packet after receiving the stop instruction.
The radio day imager digital correlation system provided by the invention receives the time service signal through the time service signal receiving module, decodes the time service signal to obtain absolute time information, and respectively sends the absolute time information to the display control unit module, the signal acquisition processing module and the storage server module; the display control unit module is used for issuing delay compensation parameters to the signal acquisition processing module according to the absolute time information, and issuing starting and stopping control instructions to the signal acquisition processing module and the storage server module; the signal acquisition processing module is used for external data acquisition and processing, corresponding delay compensation parameters are determined according to the absolute time information, and delay compensation is carried out on the acquisition channels corresponding to the signal acquisition processing module by adopting the corresponding delay compensation parameters.
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In order to more clearly illustrate the invention or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of a digital receiving system of a day imager according to the present invention;
FIG. 2 is a schematic diagram of a part of a signal acquisition processing module according to the present invention;
FIG. 3 is a timing diagram of time resolution timing provided by the present invention;
fig. 4 is a schematic flow chart of a synchronization method of the digital receiving system of the day imager provided by the invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The digital receiving system of the solar imager provided by the invention is described in detail below with reference to fig. 1 to 3.
The invention obtains absolute time information through the time service signal receiving module, and sends the absolute time information to the display control unit module, the signal acquisition processing module and the storage server module, and simultaneously, the display control unit module issues delay compensation parameters to the signal acquisition processing module, corresponding delay compensation parameters are determined according to the absolute time information, and corresponding delay compensation parameters are adopted to carry out delay compensation on acquisition channels corresponding to the signal acquisition processing module, so that delay difference of time variation among the acquisition channels caused by earth rotation is eliminated, and synchronization of relevant results of each signal acquisition channel is ensured.
Embodiment one:
the present embodiment provides a digital correlation system of radio day imager, as shown in fig. 1, the digital correlation system includes: the time service signal receiving module 10, the display control unit module 20, the signal acquisition processing module 30 and the storage server module 40.
The time signal receiving module 10 is configured to receive time signals, for example, the time signal receiving module 10 may simultaneously receive time signals of multiple satellite positioning systems, decode the time signals to obtain absolute time information, and send the absolute time information to the display control unit module 20, the signal acquisition processing module 30, and the storage server module 40, respectively. The display control unit module 20 is configured to issue delay compensation parameters to the signal acquisition processing module 30 according to the absolute time information, and issue start and stop control instructions to the signal acquisition processing module 30 and the storage server module 40. The signal acquisition processing module 30 is used for external data acquisition and processing, and determines corresponding delay compensation parameters according to absolute time information, and adopts the corresponding delay compensation parameters to perform delay compensation on the acquisition channels corresponding to the signal acquisition processing module.
In general, the display control unit module 20 sends delay compensation parameters of a future period to the signal acquisition processing module 30 before the clock arrives, the signal acquisition processing module 30 caches the delay compensation parameters corresponding to different times, and when the delay compensation is needed to be performed on the data of the signal acquisition channel at a certain moment, the corresponding delay compensation parameters are read from the corresponding cache addresses. The delay compensation parameters of each time are different, and the delay compensation parameters of each signal acquisition channel are also different at the same time, so that the signal acquisition processing module 30 determines the delay compensation parameters corresponding to each signal acquisition channel at the current time according to the absolute time information, and compensates the signals acquired by each signal acquisition channel by adopting the delay compensation parameters corresponding to each signal acquisition channel. The storage server module 40 is used for storing the data output by the signal acquisition processing module 30 according to the absolute time information.
The modules of the digital correlation system of the radio day imager of the embodiment have a synchronization function in addition to the conventional functions of the modules of the existing radio day imager. The method specifically comprises three aspects: firstly, signal acquisition is synchronous; but rather delay compensated synchronization; thirdly, data storage synchronization.
Specifically, the time service signal receiving module 10 in this embodiment is further configured to package the absolute time information into a UART protocol data packet, generate a pulse-per-second signal, and send the UART protocol data packet and the pulse-per-second signal to the signal acquisition processing module 30; the signal acquisition processing module 30 is further configured to determine absolute time information according to the second pulse signal and the UART protocol data packet, determine a corresponding delay compensation parameter according to the absolute time information, and perform delay compensation on an acquisition channel corresponding to the signal acquisition processing module 30 by using the corresponding delay compensation parameter.
In one embodiment, the radio day imager digital correlation system further comprises a clock and trigger signal distribution module 50; the time service signal receiving module 10 is further configured to generate a reference time frequency signal, and send the reference time frequency signal to the clock and trigger signal distribution module; the clock and trigger signal distribution module is used for generating sampling clock signals according to the reference time frequency signals and distributing the sampling clock signals to all the boards of the signal acquisition and processing module; the clock and trigger signal distribution module is also used for receiving the trigger signals of the signal acquisition and processing module, distributing the trigger signals into multiple paths and respectively sending the trigger signals to each board card of the signal acquisition and processing module. In general, the signal acquisition processing module 30 includes a plurality of boards for data processing, each board processes data of a plurality of channels to improve processing efficiency, in order to ensure that the data acquisition and the processing of the plurality of boards are synchronous, in this embodiment, a clock and trigger signal distribution module 50 generates a sampling clock signal, the sampling clock signal is distributed to each board of the signal acquisition processing module 30, and then each board synchronously acquires the signal by using the sampling clock; meanwhile, the clock and trigger signal distribution module 50 divides the trigger signal TrigIN sent by the main board of the signal acquisition processing module 30 into multiple paths and sends the trigger signal TrigIN to each board card of the signal acquisition processing module 30. Specifically, the time signal receiving module 10 generates a second pulse signal and a reference time-frequency signal by means of an internal atomic clock. In one embodiment, the time service signal receiving module 10 is further configured to convert the absolute time information into a time signal of NTP protocol (network time protocol, english name: networkTime Protocol) before sending the absolute time information to the display control unit module 20 and the storage server module 40, and then send the time signal of NTP protocol to the display control unit module 20 and the storage server module 40, where the display control unit module 20 and the storage server module 40 are configured to parse the time signal of NTP protocol, so that the time service signal receiving module 10, the display control unit module 20, the signal collecting and processing module 30 and the storage server module 40 keep synchronization.
Specifically, referring to fig. 1, in the present embodiment, the timing signal receiving module 10 has the capability of receiving GPS and BDS signals, and outputs a 1PPS signal (i.e. a pulse per second signal) and a reference time frequency signal. The time service signal receiving module 10 is internally provided with a high-performance atomic clock and has a GNSS (global navigation satellite system) taming function; having a plurality of RJ45 interfaces for providing NTP network time services; the system is provided with a group of RS232 serial ports for outputting time information in various formats, and the communication protocol of the RS232 serial ports is UART protocol. One NTP interface of the time service signal receiving module is connected with the display control unit module, and one NTP interface is connected with the storage server module; the 1PPS signal interface and the RS232 interface are connected with the signal acquisition processing module 30.
The time service signal receiving module 10 is connected with the clock and trigger signal distributing module 50. The clock and trigger signal distribution module 50 generates a sampling clock signal and a periodic timing pulse signal based on the standard time-frequency signal output from the timing signal receiving module 10, and distributes the sampling clock signal and the periodic timing pulse signal to be multiplexed to each board of the signal acquisition processing module 30.
The signal acquisition processing module 30 acquires external analog signals and performs delay compensation and complex correlation operation on the signals; meanwhile, the signal acquisition processing module 30 also receives the second pulse signal and the UART protocol data packet input by the time service signal receiving module 10, analyzes the second pulse signal and the UART protocol data packet, and transmits the analyzed data to the display control unit module and other modules of the system. The display control unit module 20 is used for controlling the start, stop and close of each module of the digital receiving system of the day imager, the display control unit module 20 is also used for observing the running state and calculation result of each module and displaying, and the display control unit module 20 is also used for calculating and updating delay compensation parameters in real time. The display control unit module 20 is connected with the time service signal receiving module 10, the signal acquisition processing module 30 and the storage server module 40 through RJ45 interfaces. The communication protocol between the display control unit module 20 and the time service signal receiving module 10 is NTP protocol; the communication protocol of the display control unit module 20, the signal acquisition processing module 30 and the storage server module 40 is 1000M Ethernet protocol. The storage server module 40 is used for storing complex correlation results of all channels, delay compensation parameters of the system and other system operation parameter information. The storage server module 40 is connected with the time service signal receiving module 10 through an RJ45 interface, and the communication protocol between the storage server module 40 and the time service signal receiving module 10 is NTP protocol; the storage server module 40 is connected with the display control unit module 20 through an RJ45 interface, and the communication protocol is 1000M Ethernet protocol; the storage server module 40 is connected with the signal acquisition processing module 30 through an SFP interface, and the communication protocol is 10G Ethernet protocol.
The display control unit module 20 of the present embodiment is further configured to continuously monitor the absolute time information, and issue a delay compensation parameter to the signal acquisition processing module 30 before reaching the start time. Meanwhile, the display control unit module 20 is further configured to continuously monitor the absolute time information and update the delay compensation parameter when reaching a preset time point.
In this embodiment, the signal acquisition processing module 30 is further configured to store the delay compensation parameter in a predetermined period of time in a ping-pong buffer manner.
In this embodiment, the storage server module 40 is further configured to continuously monitor absolute time information, store data output by the signal acquisition processing module 30 when a preset storage start time is reached, and attach current time information to a stored file in a data storage process, that is, assign current time information to a data packet.
As shown in fig. 2, the signal acquisition processing module 30 of the present embodiment includes a time resolution module 301, a gigabit network interface module 302, a digital-to-analog conversion module 303, a fourier transform module 304, a delay compensation module 305, a complex correlation module 306, a data encapsulation module 307, and a Mo Zhaowang interface module 308.
The digital-to-analog conversion module 303 is configured to perform digital-to-analog conversion on the received signal; the fourier transform module 304 is configured to perform fourier transform operation on the digital-to-analog converted data; the time analysis module 301 is configured to analyze the second pulse signal and the UART protocol packet sent by the time service signal receiving module, so as to obtain absolute time information; the delay compensation module 305 is configured to determine corresponding delay compensation parameters according to the absolute time information, perform delay compensation on the signal acquisition channel corresponding to the signal acquisition processing module 30 by using the corresponding delay compensation parameters, and store the delay compensation parameters in a ping-pong buffer manner; the complex correlation module 306 is configured to perform pairwise complex correlation operation on the input data; the data encapsulation module 307 is configured to encapsulate output data of the complex correlation module and current time information according to a preset format, the gigabit network interface module 302 is configured to implement a gigabit network communication protocol to communicate with the display control unit module 20, and the Mo Zhaowang interface module 308 is configured to implement a gigabit network protocol to communicate with the storage server module 20.
In this embodiment, the absolute time information is specifically transmitted by means of a serial UART protocol data packet, and the signal acquisition processing module 30 needs to analyze after receiving the UART protocol data packet, and then calculates the absolute time information according to the second pulse signal and the data obtained by analysis. The calculation is performed according to the second pulse signal and the UART protocol data packet so as to obtain absolute time information, and a timing chart of the accurate timing is shown in fig. 3. The 1PPS second pulse signal is triggered once a second and serves to indicate the time of the whole second, which is indicated by the rising edge of the second pulse. The time parsing module 301 also receives the serial data packet output by the time service signal receiving module 10 to indicate time information, and because the UART protocol communication transmission has delay, in order to accurately obtain the time information, the following method is adopted in this embodiment:
1) When receiving the rising edge of the second pulse, the time resolution module 301 adds 1s to the current time, so as to ensure the time precision;
2) When a serial port data packet is received, directly assigning the resolved absolute time information to the module time;
3) And (3) precisely counting in seconds, and precisely counting the time interval between two second pulses by using a local clock so as to acquire more precise time information.
The embodiment adopts the method to perform time analysis processing, so that the time precision can reach nanosecond level, no accumulated error exists, and the time synchronization requirement of a radio day imager digital correlation system is well met.
The display control unit module 20 is further configured to continuously monitor absolute time information, and when a set stop time is reached, issue a stop instruction to the signal acquisition processing module 30 to stop the system operation, and simultaneously stop updating the delay compensation parameter of the system; the signal acquisition processing module 30 is further configured to reset after completing the transmission of the current data packet after receiving the stop instruction. In other words, the display control unit module 20 is used for controlling the start, stop and close of the digital related system of the solar imager, observing the running state and running result of the system, and calculating and updating the delay compensation parameters in real time.
Based on the radio day imager digital correlation system, the specific flow of the system during operation comprises:
step S1: starting a radio-day imager digital correlation system, waiting for the time service signal receiving module 10 to enter a locking state, outputting time information by the time service signal receiving module 10 through an NTP interface and an RS232 interface after entering the locking state, and simultaneously outputting a 1PPS second pulse signal and a reference time frequency signal with fixed frequency.
Step S2: the clock and trigger signal distribution module 50 generates a sampling clock of the signal acquisition processing module 30 according to the reference time-frequency signal, and distributes the sampling clock into multiple channels to be output to each board of the signal acquisition processing module 30.
Step S3: the display control unit module 20 and the storage server module 40 perform NTP time calibration with the time service signal receiving module 10.
Step S4: the start time, stop time, operation mode and other operation parameters of the system are set on the display control unit module 20.
Step S5: the display control unit module 20 issues working parameters and starting instructions of the system to the signal acquisition processing module 30 and the storage server module 40 through the gigabit network interface. It should be noted that: the delay compensation parameters and various instructions described above must be issued some time before the set system start-up time (e.g., the set start-up time is 8:00, then the delay compensation parameters and instructions are issued at 7: 58).
Step S6: the display and control unit module 20 continues to monitor the system NTP time, starts calculating 1 minute before the start-up time (e.g., start-up time is 8:00, then 7: 59), and issues the system start-up followed by delay compensation ping buffer data. Because of the delay of the gigabit network packet transmission, the update interval of the delay compensation parameters is very short (for example, the delay compensation parameters are updated once in 1 ms), so as to ensure the system accuracy, the ping-pong caches store the compensation parameters for a period of time, and so as to simplify the design complexity of the system software and combine the cache size of the signal acquisition and processing module 30, in this embodiment, the ping-pong caches store the compensation parameters for 30 seconds.
Step S7: the signal acquisition processing module 30 starts signal synchronous acquisition after receiving the starting instruction, receives the time information of the 1PPS second pulse and the RS232 interface in real time, analyzes the time information of the UART format, and accurately acquires absolute time information by combining the 1PPS second pulse and the UART time information.
Step S8: the display control unit module 20 monitors the system NTP time in real time, and starts updating the pong buffer of the delay compensation parameter when the system set start time is reached. The storage server module 40 monitors the NTP time of the system in real time, and the storage server module 40 starts the operation of storing data when the start time set by the system is reached. The signal acquisition processing module 30 monitors the acquired time information in real time, and starts to receive the periodic working pulse signal when the starting time set by the system is reached.
Step S9: the signal acquisition processing module 30 monitors the periodic working pulse signal in real time, when the first high pulse is received, the signal acquisition processing module 30 records and stores the time information at the moment, and calculates the initial read address of the ping-pong buffer with delay parameters by using the time information (for example, each ping-pong buffer stores 30s of data, each address stores 1ms of delay compensation parameter, the system receives the time information corresponding to the first high pulse as 8 hours, 0 minutes, 0 seconds and 15 milliseconds, and the initial read address is 15); meanwhile, the signal acquisition processing module 30 starts an operation flow, including signal FFT (fourier transform) operation, phase compensation, bit truncation, complex correlation, and integral operation, and parameters of the phase compensation are updated by the display control unit module 20 in real time.
Step S10: the display control unit module 20 continuously monitors the system NTP time in real time, periodically calculates and transmits delay compensation parameters to the ping-pong buffer or ping-pong buffer of the signal acquisition processing module 30 according to the system NTP time (for example, the starting time of the system is 8:00, the ping-pong buffers each store 30s of buffer data, then the display control calculates and transmits the ping-pong buffer data at 8 time 0 minutes and 0 seconds, calculates and transmits the ping-pong buffer data at 8 time 0 minutes and 30 seconds, calculates and transmits the ping-pong buffer data at 8 time 1 minutes and 30 seconds, and then each minute circulates with the buffer data); the storage server module 40 continuously monitors the system NTP time in real time, and saves the processing result of the signal acquisition processing module 30, wherein the stored file name contains time information.
Step S11: the display control unit module 20 continuously monitors the NTP time of the system, and when the set system stop time is reached, the display control unit module 20 sends a stop instruction to the signal acquisition processing module 30, and stops updating the delay compensation parameter.
Step S12: after receiving the stop instruction, the signal acquisition processing module 30 resets the system after completing the transmission of the current tera-net data packet.
Step S13: after the storage server module reaches the system stop time, the data of the Mo Zhaowang interface is monitored, and after a certain period of time does not have new data, the operation of storing the data is stopped, and meanwhile, the system running information is written into a file storage disk.
Fig. 4 is a flowchart of a synchronization method of a radio day imager digital correlation system according to an embodiment of the present invention, where the day imager digital correlation system is any one of the digital correlation systems described above, as shown in fig. 4, and the synchronization method includes:
s401, a time service signal receiving module receives a time service signal, decodes the time service signal to obtain absolute time information, and sends the absolute time information to a display control unit module, a signal acquisition processing module and a storage server module respectively.
S402, the display control unit module transmits delay compensation parameters to the signal acquisition processing module according to the absolute time information, and transmits start and stop control instructions to the signal acquisition processing module and the storage server module.
S403, the signal acquisition processing module acquires and processes the analog signal, and simultaneously determines corresponding delay compensation parameters according to the absolute time information, and adopts the corresponding delay compensation parameters to perform delay compensation on an acquisition channel corresponding to the signal acquisition processing module.
S404, the storage server module stores the data output by the signal acquisition processing module according to the absolute time information.
Specifically, the time service signal receiving module encapsulates absolute time information into a UART protocol data packet, generates a second pulse signal at the same time, and sends the UART protocol data packet and the second pulse signal to the signal acquisition processing module; the signal acquisition processing module determines absolute time information according to the second pulse signal and the UART protocol data packet, determines corresponding delay compensation parameters according to the absolute time information, and adopts the corresponding delay compensation parameters to carry out delay compensation on an acquisition channel corresponding to the signal acquisition processing module.
Specifically, the time service signal receiving module generates a reference time frequency signal and sends the reference time frequency signal to the clock and trigger signal distribution module; the clock and trigger signal distribution module generates a sampling clock signal according to the reference time frequency signal and distributes the sampling clock signal to each board of the signal acquisition processing module; the clock and trigger signal distribution module receives the trigger signals of the signal acquisition and processing module, distributes the trigger signals into multiple paths and respectively sends the trigger signals to each board card of the signal acquisition and processing module.
Specifically, before the absolute time information is sent to the display control unit module and the storage server module, the time service signal receiving module converts the absolute time information into a time signal of an NTP protocol, and then sends the time signal of the NTP protocol to the display control unit module and the storage server module respectively; and the display control unit module and the storage server module analyze the time signal of the NTP protocol to obtain absolute time information.
Specifically, the display control unit module continuously monitors absolute time information and issues delay compensation parameters to the signal acquisition processing module before reaching a preset starting time.
Specifically, the display control unit module continuously monitors absolute time information, and updates the delay compensation parameter when a preset time point is reached.
Specifically, the signal acquisition processing module stores delay compensation parameters in a preset time period in a ping-pong buffer mode.
Specifically, the storage server module continuously monitors absolute time information, stores data output by the signal acquisition processing module when a preset storage start time is reached, and attaches time information of the current moment to a stored file in the process of storing the data.
Specifically, the display control unit module continuously monitors absolute time information, and when the absolute time information reaches a set stop time, a stop instruction is issued to the signal acquisition processing module, and updating of delay compensation parameters is stopped.
Specifically, the signal acquisition processing module resets after completing the transmission of the current data packet after receiving the stop instruction. The apparatus embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.
From the above description of the embodiments, it will be apparent to those skilled in the art that the embodiments may be implemented by means of software plus necessary general hardware platforms, or of course may be implemented by means of hardware. Based on this understanding, the foregoing technical solution may be embodied essentially or in a part contributing to the prior art in the form of a software product, which may be stored in a computer readable storage medium, such as ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method described in the respective embodiments or some parts of the embodiments.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A radio day imager digital correlation system, comprising: the time service signal receiving module, the display control unit module, the signal acquisition processing module and the storage server module;
the time service signal receiving module is used for receiving time service signals, decoding the time service signals to obtain absolute time information, and respectively sending the absolute time information to the display control unit module, the signal acquisition processing module and the storage server module;
the display control unit module is used for issuing delay compensation parameters to the signal acquisition processing module according to the absolute time information, and issuing starting and stopping control instructions to the signal acquisition processing module and the storage server module;
the signal acquisition processing module is used for acquiring and processing analog signals, determining corresponding delay compensation parameters according to the absolute time information, and adopting the corresponding delay compensation parameters to carry out delay compensation on acquisition channels corresponding to the signal acquisition processing module;
the storage server module is used for storing the data output by the signal acquisition processing module according to the absolute time information.
2. The digital correlation system of radio day imager of claim 1, wherein the time service signal receiving module is further configured to package the absolute time information into a UART protocol data packet, generate a pulse-per-second signal, and send the UART protocol data packet and the pulse-per-second signal to the signal acquisition processing module;
the signal acquisition processing module is further configured to determine the absolute time information according to the second pulse signal and the UART protocol data packet, determine a corresponding delay compensation parameter according to the absolute time information, and perform delay compensation on an acquisition channel corresponding to the signal acquisition processing module by adopting the corresponding delay compensation parameter.
3. The radio day imager digital correlation system of claim 2 further comprising a clock and trigger signal distribution module;
the time service signal receiving module is also used for generating a reference time frequency signal and sending the reference time frequency signal to the clock and trigger signal distribution module; the clock and trigger signal distribution module is used for generating a sampling clock signal according to the reference time frequency signal and distributing the sampling clock signal to each board card of the signal acquisition processing module; the clock and trigger signal distribution module is also used for receiving the trigger signals of the signal acquisition and processing module, distributing the trigger signals into multiple paths and respectively sending the trigger signals to each board card of the signal acquisition and processing module.
4. The radio day imager digital correlation system of claim 2 wherein said time service signal receiving module is further configured to convert said absolute time information into NTP protocol time signals before sending said absolute time information to said display control unit module and storage server module, and then send said NTP protocol time signals to said display control unit module and storage server module, respectively; the display control unit module and the storage server module are used for analyzing the time signal of the NTP protocol to obtain the absolute time information.
5. The radioday imager digital correlation system of claim 4 wherein said display and control unit module is further configured to continuously monitor said absolute time information and to issue said delay compensation parameter to said signal acquisition and processing module before a predetermined start time is reached.
6. The radioday imager digital correlation system of claim 5 wherein said display control unit module is further configured to continuously monitor said absolute time information and update said delay compensation parameter when a predetermined point in time is reached.
7. The digital correlation system of radio day imager of claim 6, wherein the signal acquisition processing module is further configured to store the delay compensation parameter in a ping-pong buffer for a predetermined period of time.
8. The digital correlation system of radio day imager of claim 4, wherein the storage server module is further configured to continuously monitor the absolute time information, store the data output by the signal acquisition processing module when a preset storage start time is reached, and attach time information of a current time to the stored file during the data storage process;
the display control unit module is also used for continuously monitoring the absolute time information, and when the absolute time information reaches the set stop time, a stop instruction is issued to the signal acquisition processing module, and the updating of the delay compensation parameter is stopped;
and the signal acquisition processing module is also used for resetting after finishing the current data packet transmission after receiving the stop instruction.
9. The radio day imager digital correlation system of claim 2 wherein the signal acquisition processing module comprises a time resolution module, a digital to analog conversion module, a fourier transform module, a delay compensation module, a complex correlation module, and a data encapsulation module;
the digital-to-analog conversion module is used for carrying out digital-to-analog conversion on the received signals; the Fourier transform module is used for carrying out Fourier transform operation on the data after digital-to-analog conversion; the time analysis module is used for analyzing the second pulse signal and the UART protocol data packet sent by the time service signal receiving module to obtain the absolute time information;
the delay compensation module is used for determining corresponding delay compensation parameters according to the absolute time information, and adopting the corresponding delay compensation parameters to carry out delay compensation on the acquisition channels corresponding to the signal acquisition processing module; meanwhile, the method is also used for storing the delay compensation parameters in a ping-pong cache mode; the complex correlation module is used for carrying out pairwise complex correlation operation on the input data of each channel;
the data packaging module is used for packaging the output data of the complex correlation module and the current time information according to a preset format.
10. A method of synchronizing a radio day imager digital correlation system, the day imager digital correlation system comprising: the time service signal receiving module, the display control unit module, the signal acquisition processing module and the storage server module; the synchronization method is characterized by comprising the following steps:
the time service signal receiving module receives a time service signal, decodes the time service signal to obtain absolute time information, and respectively sends the absolute time information to the display control unit module, the signal acquisition processing module and the storage server module;
the display control unit module transmits delay compensation parameters to the signal acquisition processing module according to the absolute time information, and transmits start and stop control instructions to the signal acquisition processing module and the storage server module;
the signal acquisition processing module acquires and processes the analog signal, and determines corresponding delay compensation parameters according to the absolute time information, and delay compensation absolute time information is carried out on an acquisition channel corresponding to the signal acquisition processing module by adopting the corresponding delay compensation parameters;
and the storage server module stores the data output by the signal acquisition processing module according to the absolute time information.
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| CN117492049B (en) * | 2023-12-29 | 2024-04-02 | 中国人民解放军国防科技大学 | High-precision time service method and device under anti-interference condition |
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