23 July 2014 Astronomical imaging with EMCCDs using long exposures
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Astronomical imaging is always limited by the detection system signal-to-noise ratio (SNR). EMCCD cameras offer many advantages for low light applications, such as sub-electron read-out noise, and low dark current with appropriate cooling. High frame rate achieved with these devices is often employed for the enhancement of SNR by acquiring and stacking multiple short exposures instead of one long exposure. EMCCDs are also suitable for applications requiring very long exposures, even when only a few photons are detected per hour. During long exposure acquisitions with a conventional CCD, slower pixel rates are usually employed to reduce the read-out noise, which dominates the CCD noise budget. For EMCCD cameras, this approach may not result in the lowest possible total noise and the effect of increasing the total exposure time may not yield the highest possible SNR for a given total integration time. In this paper, we present and discuss the experimental results obtained with an EMCCD camera that has been optimized for taking long exposures (from several seconds to several hours) of low light-level targets. These results helped to ascertain an EMCCD camera best operating parameters for long exposure astronomical imaging.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Olivier Daigle, Olivier Daigle, Oleg Djazovski, Oleg Djazovski, Jean Dupuis, Jean Dupuis, René Doyon, René Doyon, Étienne Artigau, Étienne Artigau, "Astronomical imaging with EMCCDs using long exposures", Proc. SPIE 9154, High Energy, Optical, and Infrared Detectors for Astronomy VI, 91540D (23 July 2014); doi: 10.1117/12.2056617; https://doi.org/10.1117/12.2056617


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