The Digital Polarization Solar Radio Spectrum With High Resolution

Solar radio burst is a common astronomical phenomenon.It is a kind of electromagnetic wave change caused by violent activity in some parts of the sun.It is usually related to the electron ejection inside the sun.Severe solar radio bursts have a serious impact on the Earth,including changing the state of the atmospheric ionosphere,affecting the normal operation of the navigation system and causing disruption of communication equipment.We could not only explain the physical processes related to plasma changes by studying the solar radio burst,but also find the law of energy change or analyze the important physical phenomena such as mass movement and so on.Therefore,the effective observation of the fine structure of the solar eruption for a long time has played a crucial role in the research.The solar radio spectrum analyzer is an important scientific research instrument for space observation of solar activity and could provide valuable data for basic research on the solar radio bursts.Considering the current international environment,fewer instruments of this type are used,most of them are custom-built models and cannot be universally used.In conjunction with the needs of space research,the development of solar radio spectrum analyzers is carried out.This paper obtains the approximate design by studying the radio monitoring methods at home and abroad and gradually refine to complete the design and implementation of the overall spectrum analyzer.The overall design of the program adopts the digital structure design of the contemporary trend which combines the nature of the 6-meter parabolic antenna of the project composition and uses the high-speed,fast,modular and easy-to-operate operation of digital logic operation.The paper separately designs the front end analog signal processing part,the digital signal acquisition part and the software control processing part and analyzes the feasibility of each part at the same time to guarantee the design to be realized.The analog signal processing part mainly functions as a preprocessing function for the antenna acquisition signal and is the first level to be experienced of the signal.This section contains signal amplification module,control communication module and power supply module.The signal amplification module controls the amplification of each signal and converts the input tiny signal into a larger signal acceptable by the back-end acquisition card for the purpose of completing the subsequent system sampling.The control communication module includes a single-chip microcomputer and RS485 communication design to complete the input signal.The channel selection is controllable,and the PC is used to remotely control the analog signal processing system in order to facilitate the scientific researcher.The power module provides different output voltages and satisfies the power supply of each device in the analog signal processing section.The digital signal acquisition part is to convert the input analog signal into a digital signal that can be processed at the back end.FPGA is used as the master control chip to control the PCI-E data transmission of the ADC acquisition to achieve high-speed and effective data flow implementation.The time domain data is transformed to the frequency domain completed at the bottom layer,at the same time when the acquisition and data transmission are completed,the FFT operation and polarization synthesis algorithm are added as well.The software control processing part includes the underlying board control functions,data receiving and saving functions,and data analysis functions.Using MFC to design software interface combined with the underlying driver interface functions and complete the work of the board's parameters issuing or acquisition control.The data are transmitted to the PC in the form of data packets.Using LabVIEW software and MFC interface to draw intensity maps or spectrograms and perform data analysis to provide astronomical observers to view the data and conduct research.In the end,this paper carries out experiments on the designed solar radio spectrum analyzer in the experimental environment and the actual environment.It summarizes the problems in the experimental process,optimizes the problems in the design,and improves the system stability.Finally,it obtains good test results and put the spectrum into use.After a long period of observation,it can be concluded that the design meets the requirements of digital polarization synthetic solar radio observations with a time resolution of 1 millisecond and a frequency resolution of 16 kHz.It is a stable equipment that is sufficient for the project group at this stage.