{"id":4170,"date":"2026-02-03T07:09:44","date_gmt":"2026-02-03T07:09:44","guid":{"rendered":"http:\/\/www.astro.gla.ac.uk\/users\/eduard\/cesra\/?p=4170"},"modified":"2026-05-03T16:57:28","modified_gmt":"2026-05-03T16:57:28","slug":"solar-radio-wide%e2%80%90band-spectroscopy-and-imaging-facilities-of-the-chinese-meridian-project-phase-ii-by-yihua-yan-et-al","status":"publish","type":"post","link":"https:\/\/cesra.net\/?p=4170","title":{"rendered":"Solar Radio Wide\u2010Band Spectroscopy and Imaging Facilities of the Chinese Meridian Project Phase II by Yihua Yan et al."},"content":{"rendered":"

Radioheliographs and wideband solar radio spectrographs are essential components of the Chinese Meridian Project (CMP)\u2010II (C. Wang et al., 2024) that aims to monitor the whole solar\u2010terrestrial chain of space weather events, from the lower solar atmosphere to near\u2010Earth space. This work introduce the CMP\u2010II radio instruments, including the MUSER\u2010L\/I\/H, the super\u2010wideband spectrographs of Mingantu and Chashan stations covering the wideband range of 30 MHz\u201315 GHz. The overall design, some technical details, the calibration method, and performance with some preliminary data of these instruments are presented.<\/p>\n

\"muser\"<\/p>\n

Figure 1.<\/strong> The panorama view of Mingantu Observing Station with MUSER\u2010H\/I\/L. arrays, calibration antennas.<\/p>\n

The solar radio imaging spectroscopic instruments include a Meter\u2013Decameter Wavelength Radioheliograph (30\u2013400 MHz), the extension of MUSER to lower frequency range, a Circular Array Solar Radio Telescope (150\u2013450 MHz) at Daocheng in Sichuan province (DART, J. Yan et al., 2023), and incorporate MUSER (Y. Yan et al., 2021), a Centimeter\u2010Decimeter Wavelength Radioheliograph (400 MHz\u201315 GHz) with new calibration system. The solar radio spectrometers include a Metric Wavelength Solar Radio Spectrometer (90\u2013600 MHz) at Chashan in Shandong province (Chang et al., 2024), Decameter\u2010Metric to Centimetric Wavelength Solar Radio Spectrometers (30\u2013400 MHz, 400 MHz\u20132 GHz, 2\u201315 GHz) at MUSER site, offering spectrum monitoring ability across a super wide band from 30 MHz up to 15 GHz. The super\u2010fine spectral structures of metric solar radio bursts are expected to be recorded. The data will be used to advance understanding of electron acceleration and emission mechanisms, and to improve early warnings of CME shocks and solar energetic particles. Figure 1 shows a panorama view of MUSER arrays and calibration antennas, etc., in the Mingantu Observing Station.<\/p>\n

\"radio<\/p>\n

Figure 2.<\/strong> A burst event on 6 January 2025. (a) The LASCO\/SOHO image at 05:06 UT. (b) The MUSER\u2010L multi\u2010frequencyimages in 30 MHz\u223c400 MHz at 05:07 UT. The inserted dynamic spectrum starting from 05:06 UT showing the enhancedsolar radio bursts.<\/em><\/p>\n

With the newly established calibration systems for MUSER under CMP\u2010II and the new calibration method, further progress on solar radio imaging spectroscopy has been made. Various solar radio bursts have been recorded by MUSER\u2010L\/\u2010I\/\u2010H and Mingantu spectrometers. Data are transmitted to the CMP data center daily. A solar radio burst event occurred on 6 January 2025 and observed by MUSER\u2010L. The multi\u2010frequency images in 30 MHz – 400 MHz range were obtained and the radio source at 30 MHz was as far as over 10 solar radius. The multi\u2010frequency images in 30 MHz – 400 MHz range exhibit beam\u2010like cone structure with high frequency sources confined to the lower altitude close to the Sun, as shown in Figure 2. The alignment of these multi\u2010frequency radio sources at 05:07 UT agrees with the bright structure as shown by SOHO\/LASCO C2 image around the same time period 05:06 UT. This event demonstrates the capacity to monitor solar eruptions from the Sun into interplanetary space.<\/p>\n

The Chashan Broadband Solar radio spectrometer with high temporal\u2010spectral resolutions (<1 ms, 100 kHz) at meter wavelengths covering 90\u2013600 MHz has been developed (CBSm, Chang et al., 2024). The major scientific purpose of CBSm is to record superfine spectral structures of metric solar radio bursts. See Figure 3 for examples of such spectral fine structures recorded by CBSm. Since 10 November 2022, CBSm has detected many solar radio bursts, including week\u2010long Type I bursts\/noise storms, 50 Type II bursts, several thousand Type III bursts, and 20 Type IV bursts.<\/p>\n

\"dynamic<\/p>\n

Figure 3. <\/strong>Top left panel is Chashan Solar Radio Spectrometer. (a) An example of stripes with an overall wavy morphology in the 8 May 2024 event, with beaded structure emerging in the middle portion (adapted from C. Li et al., 2025). (b) Type II bursts from 00:26:30 UT to 00:29:30 UT on 18 December 2023. (c) A type II burst from 07:50:00 UT to 08:00:00 UT on 5 February 2025.(d) Type III bursts from 23:29:00 UT to 23:30:00 UT on 18 March 2023. (e) Polarization degree corresponding to (d).<\/em><\/p>\n

The data presented in this paper are available from the National Space Science Data Center for the Chinese Meridian Project (https:\/\/data.meridianproject.ac.cn). Some data may be subject to a proprietary period; please refer to the data center’s access policy. MUSER event data can be visited at http:\/\/120.193.217.157:5404\/solar_event_database\/. Local MUSER\u2010L data can be browsed at http:\/\/120.193.217.157:5403\/muser\/MUSER\u2010L\/, and CBSm data sets can be accessed at http:\/\/47.104.87.104\/SRData\/CBSm\/.<\/p>\n

Conclusions<\/strong><\/p>\n

The facilities described here offer uniquely broad frequency coverage and advanced imaging and spectral capability. Their open data policy will enable collaborative research and enhance global space weather monitoring and forecasting.<\/p>\n

Additional info<\/strong>: The nugget is based on the recently published paper by Yihua Yan et al., 2025, Space Weather<\/em>\uff08open access\uff09, DOI:10.1029\/2025SW004595<\/a><\/p>\n

References<\/strong><\/p>\n

Chang, S., Wang, B., Lu, G., Shen, Y., Bai, Y., Shang, Z., et al. (2024). Development of a 90\u2013600 MHz meter\u2010wave solar radio spectrometer. The<\/em> Astrophysical Journal \u2010 Supplement Series<\/em>, 272<\/em>(1), 21. https:\/\/doi.org\/10.3847\/1538\u20104365\/ad3de7<\/p>\n

Li, C., Chen, Y., Wang, B., Zhong, Z., Tan, B., Ning, Z., et al. (2025). A novel fine spectral structure of solar radio bursts with periodic beaded stripes observed by CBSm of CMP\u2010II. Science China Physics, Mechanics & Astronomy, 68(10), 109611. https:\/\/doi.org\/10.1007\/s11433\u2010025\u20102716\u20104.<\/p>\n

Yan, J., Wu, J., Wu, L., Yang, Y., Wu, J., Yan, Y., & Wang, C. (2023). A super radio camera with a one\u2010kilometre lens. Nature Astronomy<\/em>, 7<\/em>(6), 750. https:\/\/doi.org\/10.1038\/s41550\u2010023\u201001932\u2010y<\/p>\n

Yan, Y., Chen, Z., Wang, W., Liu, F., Geng, L., Chen, L., et al. (2021). Mingantu spectral radioheliograph for solar and space weather studies. Frontiers in Astronomy and Space Sciences<\/em>, 8<\/em>, 20. https:\/\/doi.org\/10.3389\/fspas.2021.584043<\/a><\/p>\n

Wang, C., Xu, J., Chen, Z., Li, H., Feng, X., Huang, Z., & Wang, J. (2024). China\u2019s ground\u2010based space environment monitoring network\u2014Chinese meridian project (CMP). Space Weather, 22(7), e2024SW003972. https:\/\/doi.org\/10.1029\/2024sw003972<\/p>\n

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Radioheliographs and wideband solar radio spectrographs are essential components of the Chinese Meridian Project (CMP)\u2010II (C. Wang et al., 2024) that aims to monitor the whole solar\u2010terrestrial chain of space weather events, from the lower solar atmosphere to near\u2010Earth space. This work introduce the CMP\u2010II radio instruments, including the MUSER\u2010L\/I\/H, the super\u2010wideband spectrographs of Mingantu and Chashan stations covering the wideband range of 30 MHz\u201315 GHz. The overall design, some […]<\/a><\/p>\n<\/div>","protected":false},"author":1,"featured_media":4171,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[108,66],"class_list":["post-4170","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-nuggets","tag-mingantu-spectral-radioheliograph-muser","tag-solar-radio-emission"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t