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Development of a Front End Array for Broadband Phased Array Receiver

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Research in Astronomy and Astrophysics 2024年第4期24卷 60-70页

作者： Kai Wang Liang Cao Jun Ma Xue-Feng Duan Hao Yan Mao-Zheng Chen Yun-Wei Ning Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 8300lChina University of the Chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

The receiver is a signal receiving device placed at the focus of the *** order to improve the observation efficiency,the concept of phased array receiver has been proposed in recent years,which places a small phased array at the focal plane of the reflector,and flexible pattern and beam scanning functions can be achieved through a beamforming *** combined with the element multiplexing,all beams within the entire field of view can be observed simultaneously to achieve continuous sky *** article focuses on the front-end array of phased array receiver at 0.7-1.8 GHz for QiTai Telescope,and designs a Vivaldi antenna array of PCB structure with dual line *** polarization antenna is designed to arrange in a rectangle manner by 11×*** on the simulation results of the focal field,32,18,and eight elements were selected to form one beam at 0.7,1.25,and1.8 *** analog beamforming network was constructed,and the measured gains of axial beam under uniform weighting were 19.32,13.72,and 15.22 *** the beam scanning method of reflector antenna,the pattern test of different position element sets required for PAF beam scanning was carried out under independent *** pattern optimization at 1.25 GHz was carried out by weighting method of conjugate field *** with uniform weighting,the gain,sidelobe level,and main beam direction under conjugate field matching have been *** the above test and simulation results are slightly different,which is related to the passive array and laboratory testing condition,the relevant work has accumulated experience in the development of the front-end array for the phased array receiver,and has good guiding significance for future performance verification after the array is installed on the telescope.

关键词： telescopes instrumentation:detectors techniques:radar astronomy

PSRDP:A Parallel Processing Method for Pulsar Baseband Data

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Research in Astronomy and Astrophysics 2024年第1期24卷 300-310页

作者： Ya-Zhou Zhang Hai-Long Zhang Jie Wang Xin-Chen Ye Shuang-Qiang Wang Xu Du Han Wu Ting Zhang Shao-Cong Guo Meng Zhang Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China National astronomical Data Center Beijing 100101China Southeast University Nanjing 211189China School of Cyber Science and Engineering Qufu Normal UniversityQufu 273165China

To address the problem of real-time processing of ultra-wide bandwidth pulsar baseband data,we designed and implemented a pulsar baseband data processing algorithm(PSRDP)based on GPU parallel computing *** can perform operations such as baseband data unpacking,channel separation,coherent dedispersion,Stokes detection,phase and folding period prediction,and folding integration in GPU *** tested the algorithm using the J0437-4715 pulsar baseband data generated by the CASPSR and Medusa backends of the Parkes,and the J0332+5434 pulsar baseband data generated by the self-developed backend of the Nan Shan Radio *** obtained the pulse profiles of each baseband *** experimental analysis,we have found that the pulse profiles generated by the PSRDP algorithm in this paper are essentially consistent with the processing results of Digital Signal Processing Software for Pulsar Astronomy(DSPSR),which verified the effectiveness of the PSRDP ***,using the same baseband data,we compared the processing speed of PSRDP with DSPSR,and the results showed that PSRDP was not slower than DSPSR in terms of *** theoretical and technical experience gained from the PSRDP algorithm research in this article lays a technical foundation for the real-time processing of QTT(Qi Tai radio Telescope)ultra-wide bandwidth pulsar baseband data.

关键词： (stars:)pulsars:general methods:data analysis techniques:miscellaneous

UWLPIPE: Ultra-wide Bandwidth Low-frequency Pulsar Data Processing Pipeline

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Research in Astronomy and Astrophysics 2024年第7期24卷 148-160页

作者： Ya-Zhou Zhang Hai-Long Zhang Jie Wang Jian Li Xin-Chen Ye Shuang-Qiang Wang Xu Du Han Wu Ting Zhang Shao-Cong Guo Xinjiang astronomical Observatory Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of Radio Astronomy Chinese Academy of Sciences National astronomical Data Center Southeast University

For real-time processing of ultra-wide bandwidth low-frequency pulsar baseband data, we designed and implemented an ultra-wide bandwidth low-frequency pulsar data processing pipeline(UWLPIPE) based on the shared ringbuffer and GPU parallel technology. UWLPIPE runs on the GPU cluster and can simultaneously receive multiple 128 MHz dual-polarization VDIF data packets preprocessed by the front-end FPGA. After aligning the dual-polarization data, multiple 128M subband data are packaged into PSRDADA baseband data or multi-channel coherent dispersion filterbank data, and multiple subband filterbank data can be spliced into wideband data after time alignment. We used the Nanshan 26 m radio telescope with the L-band receiver at964 ～ 1732 MHz to observe multiple pulsars. Finally, we processed the data using DSPSR software, and the results showed that each subband could correctly fold out the pulse profile, and the wideband pulse profile accumulated by multiple subbands could be correctly aligned.

关键词： (stars:) pulsars: general methods: data analysis techniques: miscellaneous

The RFI Fast Mitigation Algorithm Based on Block LMS Filter

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Research in Astronomy and Astrophysics 2024年第1期24卷 265-272页

作者： Han Wu Hai-Long Zhang Ya-Zhou Zhang Jie Wang Xu Du Ting Zhang Xin-Chen Ye Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China National astronomical Data Center Beijing 100101China

The radio telescope possesses high sensitivity and strong signal collection *** receiving celestial radiation signals,it also captures Radio Frequency Interferences(RFIs)introduced by human ***,as signals originating from sources other than the astronomical targets,significantly impacts the quality of astronomical *** paper presents an RFI fast mitigation algorithm based on block Least Mean Square(LMS)*** enhances the traditional adaptive LMS filter by grouping L adjacent time-sampled points into one block and applying the same filter coefficients for filtering within each *** transformation reduces multiplication calculations and enhances algorithm efficiency by leveraging the time-domain convolution *** algorithm is tested using baseband data from the Parkes 64 m radio telescope's pulsar observations and simulated *** results confirm the algorithm's effectiveness,as the pulsar profile after RFI mitigation closely matches the original pulsar profile.

关键词： methods:data analysis techniques:interferometric (stars:)pulsars:individual(J0437-4715)

A Cross-matching Service for Data Center of Xinjiang astronomical Observatory

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Research in Astronomy and Astrophysics 2024年第1期24卷 119-127页

作者： Hai-Long Zhang Jie Wang Xin-Chen Ye Wan-Qiong Wang Jia Li Ya-Zhou Zhang Xu Du Han Wu Ting Zhang Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China National astronomical Data Center Beijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Cross-matching is a key technique to achieve fusion of multi-band astronomical catalogs. Due to different equipment such as various astronomical telescopes, the existence of measurement errors, and proper motions of the celestial bodies, the same celestial object will have different positions in different catalogs, making it difficult to integrate multi-band or full-band astronomical data. In this study, we propose an online cross-matching method based on pseudo-spherical indexing techniques and develop a service combining with high performance computing system(Taurus) to improve cross-matching efficiency, which is designed for the Data Center of Xinjiang astronomical Observatory. Specifically, we use Quad Tree Cube to divide the spherical blocks of the celestial object and map the 2D space composed of R.A. and decl. to 1D space and achieve correspondence between real celestial objects and spherical patches. Finally, we verify the performance of the service using Gaia 3 and PPMXL catalogs. Meanwhile, we send the matching results to VO tools-Topcat and Aladin respectively to get visual results. The experimental results show that the service effectively solves the speed bottleneck problem of crossmatching caused by frequent I/O, and significantly improves the retrieval and matching speed of massive astronomical data.

关键词： virtual observatory tools astronomical databases:miscellaneous catalogs

Exploring Sulfur Chemistry in TMC-1 with NSRT

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Chinese Physics Letters 2024年第2期41卷 129-132页

作者： Wasim Iqbal Xiaohu Li Juan Tuo Ryszard Szczerba Yanan Feng Zhenzhen Miao Jiangchao Yang Jixing Ge Gleb Fedoseev Donghui Quan Qiang Chang Chuan-Lu Yang Tao Yang Gao-Lei Hou Yong Zhang Xuan Fang Xia Zhang Fangfang Li Rong Ma Xiaomin Song Zhiping Kou Yuxuan Sun Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China Nicolaus Copernicus astronomical Center Rabia´nska 887-100 Toru´nPoland Research Laboratory for Astrochemistry Ural Federal UniversityKuibysheva St.48620026 EkaterinburgRussia astronomical Computing Research Center Zhejiang LaboratoryHangzhou 311100China School of Physics and Optoelectronic Engineering Shandong University of TechnologyZibo 255000China School of Physics and Optoelectronic Engineering Ludong UniversityYantai 264025China State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter School of PhysicsXi’an Jiaotong UniversityXi’an 710049China School of Physics and Astronomy Sun Yat-sen UniversityGuangzhou 510275China Laboratory for Space Research Faculty of ScienceThe University of Hong KongHong KongChina National astronomical Observatories Chinese Academy of SciencesBeijing 100012China

There have been several studies on sulfur depletion in dense cores like TMC-1(Taurus Molecular Cloud 1),employing updated reaction networks for sulfur species to explain the missing sulfur in the gas within dense *** of these studies used a C/O ratio of 0.7 or *** present NSRT(NanShan 26m Radio Telescope)observations of TMC-1 alongside results from time-dependent chemical simulations using an updated chemical *** findings highlight the impact of the C/O ratio on the gas-phase evolution of C2S and *** simulation results show that the C/O ratio is an important parameter,playing a fundamental role in determining the gas-phase abundances of sulfur species in dense cores.

关键词： sulfur Sulfur depletion

A Search for Radio Pulsars in Supernova Remnants Using FAST with One Pulsar Discovered

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Chinese Physics Letters 2024年第2期41卷 133-136页

作者：张振闫文明袁建平王娜白俊涛温志刚李保达解进涛赵德王榆斌翟楠楠 Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy and Technology(Chinese Academy of Sciences) Beijing 100101China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China College of Physics GuiZhou UniversityGuizhou 550025China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China School of Physics and Electronic Engineering Sichuan University of Science&EngineeringZigong 643000China

We report the results of a search for radio pulsars in five supernova remnants(SNRs)with the FAST *** observations were made using the 19-beam receiver in“snapshot”*** integration time for each pointing was 10 *** discovered a new pulsar,PSR J1845–0306,which has a spin period of 983.6 ms and a dispersion measure of 444.6±2.0 cm^(−3)·pc,in observations of SNR G29.6+*** judge the association between the pulsar and the SNR,further verification is *** also re-detected some known pulsars in the data from SNRs G29.6+0.1 and G29.7–*** pulsars were detected in the observations of the other three SNRs.

关键词： observations Pulsar pulsar

Review of artificial intelligence applications in astronomical data processing

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astronomical Techniques and instruments 2024年第1期1卷 1-15页

作者： Hailong Zhang Jie Wang Yazhou Zhang Xu Du Han Wu Ting Zhang Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China National astronomical Data Center Beijing 100101China

Artificial Intelligence(AI)is an interdisciplinary research field with widespread *** aims at developing theoretical,methodological,technological,and applied systems that simulate,enhance,and assist human ***,notable accomplishments of artificial intelligence technology have been achieved in astronomical data processing,establishing this technology as central to numerous astronomical research areas such as radio astronomy,stellar and galactic(Milky Way)studies,exoplanets surveys,cosmology,and solar *** article systematically reviews representative applications of artificial intelligence technology to astronomical data processing,with comprehensive description of specific cases:pulsar candidate identification,fast radio burst detection,gravitational wave detection,spectral classification,and radio frequency interference ***,it discusses possible future applications to provide perspectives for astronomical research in the artificial intelligence era.

关键词： astronomical techniques astronomical methods Astroinformatics

A Search Technique Based on Deep Learning for Fast Radio Bursts and Initial Results for FRB 20201124A with the NSRT

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Research in Astronomy and Astrophysics 2022年第10期22卷 77-85页

作者： Yan-Ling Liu Jian Li Zhi-Yong Liu Mao-Zheng Chen Jian-Ping Yuan Na Wang Rai Yuen Hao Yan Xinjiang astronomical observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210033China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

The origin and phenomenology of Fast Radio Bursts(FRBs) remain unknown. Fast and efficient search technology for FRBs is critical for triggering immediate multi-wavelength follow-up and voltage data dump. This paper proposes a dispersed dynamic spectra search(DDSS) pipeline for FRB searching based on deep learning, which performs the search directly from observational raw data, rather than relying on generated FRB candidates from single-pulse search algorithms that are based on de-dispersion. We train our deep learning network model using simulated FRBs as positive and negative samples extracted from the observational data of the Nanshan 26 m radio telescope(NSRT)at Xinjiang astronomical Observatory. The observational data of PSR J1935+1616 are fed into the pipeline to verify the validity and performance of the pipeline. Results of the experiment show that our pipeline can efficiently search single-pulse events with a precision above 99.6%, which satisfies the desired precision for selective voltage data dump. In March 2022, we successfully detected the FRBs emanating from the repeating case of FRB 20201124A with the DDSS pipeline in L-band observations using the NSRT. The DDSS pipeline shows excellent sensitivity in identifying weak single pulses, and its high precision greatly reduces the need for manual review.

关键词： radio continuum general-methods data analysis-methods observational