Calibration procedures for the CHASE/HIS science data

Abstract

The Hα line is an important optical line in solar observations containing the information from the photosphere to the chromosphere. To study the mechanisms of solar eruptions and the plasma dynamics in the lower atmosphere, the Chinese Hα Solar Explorer (CHASE) was launched into a Sun-synchronous orbit on October 14, 2021. The scientific payload of the CHASE satellite is the Hα Imaging Spectrograph (HIS). The CHASE/HIS acquires, for the first time, seeing-free Hα spectroscopic observations with high spectral and temporal resolutions. It consists of two observational modes. The raster scanning mode provides full-Sun or region-of-interest spectra at Hα (6559.7-6565.9 Å) and Fe I (6567.8-6570.6 Å) wavebands. The continuum imaging mode obtains full-Sun photospheric images at around 6689 Å. In this paper, we present detailed calibration procedures for the CHASE/HIS science data, including the dark-field and flat-field correction, slit image curvature correction, wavelength and intensity calibration, and coordinate transformation. The higher-level data products can be directly used for scientific research.

arXiv comment9 pages, 7 figures

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Cited by in corpus (10)

• The Chinese Hα Solar Explorer (CHASE) mission: An overview
• First detection of transverse vertical oscillation during the expansion of coronal loops
• Spectral Observations and Modeling of a Solar White-light Flare Observed by CHASE
• Three-dimensional velocity fields of the solar filament eruptions detected by CHASE
• Statistical analysis of the Si I 6560.58 Å line observed by CHASE
• High-resolution Observations of a C9.3 White-light Flare and Its Impact on the Solar Photosphere
• Enhanced Non-Thermal Line Broadening inside Coronal Cavities above Solar Prominences revealed by Spectral Imaging CoronaGraph
• Transverse vertical oscillations during the contraction and expansion of coronal loops
• The Kinematical Behavior of Solar Eruptive Filaments Affected by the Poloidal Magnetic Field
• Solar flare ribbons structured by uncombed chromospheric loops