2012/01/11 by Steve B. Howell · 1 citation
Engineering · Physics and Astronomy · #Astrophysics #Band-pass filter #CCD and CMOS Imaging Sensors #Calibration #Computer science #Computer vision #Detector #Field of view #Filter (signal processing) #Flatness (cosmology) #Infrared Target Detection Methodologies #Interference filter #Neon #Optics #Photocathodes and Microchannel Plates #Physics #Sky #Wavelength #astro-ph.IM
paper · pdf · doi:10.1086/664741
accepted to PASP
arxiv created 2012/01/11 · openalex publication_date 2012/03/01 · arxiv updated 2015/06/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Fringing in CCD images is troublesome from the aspect of photometric quality and image flatness in the final reduced product. Additionally, defringing during calibration requires the inefficient use of time during the night to collect and produce a "supersky" fringe frame. The fringe pattern observed in a CCD image for a given near-IR filter is dominated by small thickness variations across the detector, with a second-order effect caused by the wavelength extent of the emission lines within the bandpass that produce the interference pattern. We show that essentially any set of emission lines that generally match the wavelength coverage of the night-sky emission lines within a bandpass will produce an identical fringe pattern. We present an easy, inexpensive, and efficient method that uses a neon lamp as a flat-field source and produces high-S/N fringe frames to use for defringing an image during the calibration process.