Data Release of Solar Radio Bursts observed by CBSm at the metric wavelength by Yao Chen et al.

Here we release the spectral data of solar radio bursts recorded by the Chashan Broadband Solar radio spectrograph (CBSm), located in the Chashan mountain (E122°.30, N36°.84) that is the southern tip of Shandong Peninsula of China.

CBSm is supported by the Chinese Meridian Space Weather Monitoring Project (II) and Shandong University. It is designed and operated by the Laboratory for ElectromAgnetic Detection of Institute of Space Sciences (LEAD, ISS), Shandong University.

CBSm observes the Sun from 90 to 600 MHz with a 12m parabolic antenna fed by a dual-polarization LPDA feed. Its receiver adopts a high-speed two-channel 14-bit ADC acquisition card, with a sampling rate of 1.25 GSPS. The CBSm receiver implements a 16k-point FFT algorithm with FPGA KU115. The default frequency and temporal resolutions are 76.294 kHz and 0.839 ms (up to 0.21 ms), respectively. The noise coefficient of the system is less than 1 dB, the dynamic range is more than 60 dB, and the sensitivity is as high as 1 SFU that is estimated for integration within 1ms and a bandwidth of 100 kHz at 300 MHz. The main purpose of CBSm is to record ultra-fine spectral structures of metric solar radio bursts.

The CBSm started its routine observation since Nov. 2022. It has recorded many radio bursts, including type I bursts that may last for weeks, hundreds of type IIIs, tens of type II and IV bursts, despite relatively-strong radio interference.

Below we presented a photo of the 12m antenna and two examples of the CBSm data.

Figure 1: The Chashan Broadband Solar radio spectrograph (CBSm), located in the Chashan mountain (E122°.30, N36°.84) that is the southern tip of Shandong Peninsula of China.

Figure 2: Two examples of the CBSm bursts observed on May 8 2023 and the same date in 2024.

The data of the CBSm type II bursts together with some intriguing bursts with fine spectral structures can be found via the website (http://47.104.87.104/SRData/CBSm/RadioBurstEvent/typeII/typeIIburst_show.html). These spectrographs are given by the data integrated over 100 ms and 610kHz for a better signal-noise ratio. We are working to calibrate these data in both flux densities and levels of polarization. The daily spectra data can be viewed online at http://47.104.87.104/ SRData/CBSm/dailyView/  and/or http://47.104.87.104/ SRData/CBSm/dailyFits/.

The introduction to CBSm can be found online at https://iopscience.iop.org/article/10.3847/1538-4365/ad3de7. Please contact Dr. Yao CHEN (the chief scientist of the Chashan Solar Observatory) at yaochen@sdu.edu.cn for collaborations in scientific research on solar radio bursts. For the high-resolution data of the bursts or other inquiries, please contact Dr. Bing Wang at wbing@sdu.edu.cn.