Optimization of the multiple sampling and signal extraction in non-destructive exposures

Abstract

We derive the full covariance matrix formulae are derived for proper treatment of correlations in signal fitting procedures, extending the results from previous publications. The straight line fits performed with these matrices demonstrate that a significantly higher signal to noise is obtained when the fluence exceeds 1 e/sec/pix in particular in long (several hundreds of seconds) spectroscopic exposures. The improvement arising from the covariance matrix is particularly strong for the initial intercept of the fit at t=0, a quantity which provides a useful redundancy to cross check the signal quality. We demonstrate that the mode that maximizes the signal to noise ratio in all ranges of fluxes studied in this paper is the one that uses all the frames sampled during the exposure. While at low flux there is no restriction on the organization of frames within groups for fluxes lower than 1 e/sec/pix, for fluxes exceeding this value the coadding of frames shell be avoided.

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Cited by in corpus (4)

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• Euclid: Estimation of the impact of correlated readout noise for flux measurements with the Euclid NISP instrument
• Low noise flux estimate and data quality control monitoring in EUCLID-NISP cosmological survey
• Euclid preparation. Overview of Euclid infrared detector performance from ground tests