Data processing of visible emission line coronagraph onboard ADITYA-L1

• DOI: 10.1016/j.asr.2024.03.058
• Publication Date: 2024-03-28T18:37:42Z
• Authors: Muthu Priyal; Jagdev Singh; B. Raghavendra Pr...; Chavali Sumana; Varun Kumar; Shalabh Mishra; S.N. Venkata; G. Sindhuja; K. Sasikumar Raja; Amit Kumar; Sanal krishnan; Bhavana S. Hegde; D. Utkarsha; Natarajan Venkata...; Pawankumar Somasu...; S. Nagabhushana; P.U. Kamath; S. Kathiravan; T. Vishnu Mani; Suresh Basavaraju; Rajkumar Chavan; P. Vemareddy; B. Ravindra; S.P. Rajaguru; K. Nagaraju; Wageesh Mishra; Jayant Joshi; Tanmoy Samanta; Piyali Chatterjee; C. Kathiravan; R. Ramesh
• Keywords: Coronagraph

ADITYA-L1 is India's first dedicated mission to observe the sun and its atmosphere from a halo orbit around L1 point. Visible emission line coronagraph (VELC) is the prime payload on board at Aditya-L1 to observe the sun's corona. VELC is designed as an internally occulted reflective coronagraph to meet the observational requirements of wide wavelength band and close to the solar limb (1.05 Ro). Images of the solar corona in continuum and spectra in three emission lines 5303Å [Fe xiv], 7892Å [Fe xi] and 10747 [Fe xiii] obtained with high cadence to be analyzed using software algorithms automatically. A reasonable part of observations will be made in synoptic mode, those, need to be analyzed and results made available for public use. The procedure involves the calibration of instrument and detectors, converting the images into fits format, correcting the images and spectra for the instrumental effects, align the images etc. Then, develop image processing algorithms to detect the occurrence of energetic events using continuum images. Also derive physical parameters, such as temperature and velocity structure of solar corona using emission line observations. Here, we describe the calibration of detectors and the development of software algorithms to detect the occurrence of CMEs and analyze the spectroscopic data.