The Commensal Radio Astronomy FasT Survey (CRAFTS; Li et al. 2018) is one of the Five-hundred-meter Aperture Spherical radio Telescope (FAST) key projects. The CRAFTS survey simultaneously records wide-band spectral line data, narrow-band spectral line data, and high-time-resolution time-domain data, enabling diverse scientific objectives including extra-galactic neutral hydrogen (HI), Galactic HI, pulsars, and fast radio bursts (FRB). The wide-band spectral line data cover 1.0–1.5 GHz frequency range with a frequency resolution of 7.6 kHz. Its primary scientific objectives include the study of extra-galactic HI, cosmic large-scale structures, Galactic radio recombination lines, and etc. By simultaneously conducting HI mapping and FRB searches, CRAFTS has multiplied FAST's survey efficiency, realizing what Nature Astronomy termed the "as optimized as possible" radio survey mode (Keane 2018). 

Having been conducted for five years since 2020, CRAFTS has completed 27% of its planned sky coverage. With preliminary processing of its wide-band spectral line data being close to complete, we pre-release the data cube to facilitate scientific research in fields such as extra-galactic studies. This pre-release, launched on April 1, 2025 via ScienceDB, initially includes 14 observational sessions totaling 70 hours. Data coverage will expand progressively over next few weeks, with concurrent quality improvements. Due to severe radio interference in early datasets, this pre-release only includes approximately 900 hours of data collected from July 31, 2021 to January 30, 2025 (frequency range of 1323 MHz to 1419 MHz), yielding ~1.5 TB calibrated data. Remaining data will be fully released in subsequent phases.  All datasets are openly accessible without collaboration requirements. 

CRAFTS is led by Professor Di Li (NAOC/Tsinghua University), with wide-band data processing led by NAOC, in partnership with Zhejiang Lab and Guizhou Normal University.   

Release webpage: https://hiverse.zero2x.org/wide

Data link: https://doi.org/10.57760/sciencedb.Fastro.00024

Sky coverage of the CRAFTS observations. This pre-release includes 14 observational sessions totaling 70 hours. Data within the blue regions will be released incrementally over the next few weeks. The gray regions are excluded from this release and are anticipated to be fully released in the next official data release. Zenith Angle (ZA) refers to the angle between the telescope’s pointing direction and the zenith (directly overhead, at an elevation of 90°). FAST can observe up to a ZA of 40° (two black parallels), and keep its efficiency within 26.4° (two red parallels).

References:

Li, et al. 2018, IEEE Microwave Magazine, Vol 19, Issue 3, pp112-119

Keane, 2018, Nature Astronomy, Vol 2, pp865-872