CCD riddle: a) signal vs time: linear; b) signal vs variance: non-linear

Downing, Mark; Baade, D.; Sinclaire, P.; Deiries, S.; Christen, F.

doi:10.1117/12.671457

Cited by 50 publications

(68 citation statements)

References 3 publications

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“…1, the differences of the Poisson distribution are most noticeable at low fluxes and are determined by readout noise and bandwidth of a video channel: Inconsiderable fall of the Fano factor in the greaterflux region appears due to the dispersion decrease which is discussed in recent works (Downing et al, 2006;Ma et al, 2014;Guyonnet et al, 2015) and is probably associated with a charge redistribution between pixels. This effect is one more factor limiting accuracy at high levels of signal in pixel.…”

Section: Distortions Of Ccd Counts' Statisticsmentioning

confidence: 99%

Study of distortions in statistics of counts in CCD observations using the fano factor

Afanasieva

2016

Astrophys. Bull.

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Section: Distortions Of Ccd Counts' Statisticsmentioning

confidence: 99%

Study of distortions in statistics of counts in CCD observations using the fano factor

Afanasieva

2016

Astrophys. Bull.

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“…Due to the Poisson-like distribution the photon shot noise variance σ 2 shot should scale linearly with mean signal level. Deviations from this linear relationship can provide an indication of a nonlinear radiometric response (Bohndiek et al, 2008) or a charge-sharing mechanism between pixels (Downing et al, 2006;Stefanov, 2014).…”

Section: Noisementioning

confidence: 99%

Design and characterization of specMACS, a multipurpose hyperspectral cloud and sky imager

Ewald

Kölling²,

Baumgartner

et al. 2016

Atmos. Meas. Tech.

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Abstract. The new spectrometer of the Munich Aerosol Cloud Scanner (specMACS) is a multipurpose hyperspectral cloud and sky imager designated, but is not limited to investigations of cloud-aerosol interactions in Earth's atmosphere. With its high spectral and spatial resolution, the instrument is designed to measure solar radiation in the visible and shortwave infrared region that is reflected from, or transmitted through clouds and aerosol layers. It is based on two hyperspectral cameras that measure in the solar spectral range between 400 and 2500 nm with a spectral bandwidth between 2.5 and 12.0 nm. The instrument was operated in ground-based campaigns as well as aboard the German High Altitude LOng Range (HALO) research aircraft, e.g., during the ACRIDICON-CHUVA campaign in Brazil during summer 2014.This paper describes the specMACS instrument hardware and software design and characterizes the instrument performance. During the laboratory characterization of the instrument, the radiometric response as well as the spatial and spectral resolution was assessed. Since the instrument is primarily intended for retrievals of atmospheric quantities by inversion of radiative models using measured radiances, a focus is placed on the determination of its radiometric response. Radiometric characterization was possible for both spectrometers, with an absolute accuracy of 3 % at their respective central wavelength regions. First measurements are presented which demonstrate the wide applicability of the instrument. They show that key demands are met regarding the radiometric and spectral accuracy which is required for the intended remote sensing techniques.

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Section: Lateral Electric Fields and Charge Re-distributionmentioning

confidence: 99%

“…These sources can include static 'structural' features that are part of the device design and dynamic sources related to the charge collection process itself. Recent work by a number of researchers 4,5,7,9,10,15,16 has exposed more clearly the effects that both static and dynamic electric fields can have on the effective mapping of photoconversion location to charge collection location.As example of structural design features that can produce charge redistribution, we present the electrostatic effects of the 'scupper' feature that is frequently implemented to guard against charge generated at the periphery of the device from contaminating the signal in the imaging array.A subtler static structural feature is the variation in doping concentrations in the silicon substrate. This variation leads to a deformation of the electric fields that guide the electrons generated by photo-conversion to the collection site in the potential wells.…”

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confidence: 99%

Electro-optical testing of fully depleted CCD image sensors for the Large Synoptic Survey Telescope camera

et al. 2014

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The LSST Camera science sensor array will incorporate 189 large format Charge Coupled Device (CCD) image sensors. Each CCD will include over 16 million pixels and will be divided into 16 equally sized segments and each segment will be read through a separate output amplifier.The science goals of the project require CCD sensors with state of the art performance in many aspects. The broad survey wavelength coverage requires fully depleted, 100 micrometer thick, high resistivity, bulk silicon as the imager substrate. Image quality requirements place strict limits on the image degradation that may be caused by sensor effects: optical, electronic, and mechanical.In this paper we discuss the design of the prototype sensors, the hardware and software that has been used to perform electro-optic testing of the sensors, and a selection of the results of the testing to date. The architectural features that lead to internal electrostatic fields, the various effects on charge collection and transport that are caused by them, including charge diffusion and redistribution, effects on delivered PSF, and potential impacts on delivered science data quality are addressed. INTRODUCTIONThe Large Synoptic Survey Telescope (LSST) will combine an 8.4 meter telescope with a light-gathering power among the largest in the world and a camera made up of more than 3 billion pixels. Data on billions of galaxies will be used to create a three dimensional map of the Universe with unprecedented depth and detail. This map will then be used to tomographically map dark matter, chart the clustering of galaxies, and to characterize the properties of dark energy. In addition, a wide range of other topics in astrophysics will be probed using the 15 Terabytes of imaging data that the system will produce each night.Of particular importance in executing the LSST science mission is the fidelity of both the photometric and astrometric measurements that can be made using the data that the instrument produces. As example, the detection and distribution mapping of dark matter via the analysis of subtle geometric distortion of galactic shapes caused by gravitational lensing ("weak lensing") requires precision in both photometric and astrometric measurement.The science goals of the project 1 require CCD sensors with state of the art performance in many aspects. The telescope plate scale and expected image quality require a sensor pixel size of no more than 10 micrometers square. The broad survey wavelength coverage and sensitivity requirements at long wavelengths (~1000 nm) dictate the use of thick, fully depleted, high resistivity bulk silicon as the imager substrate. Data throughput requirements impose a cadence of 15-second exposures and two-second imager read times. Survey optical depth goals require a per-pixel amplifier read noise PROTOTYPE LSST CCDS AND TEST FACILITIES Baseline CCD architectureIn order to meet the various requirements outlined above, a nominal sensor architecture and design was established. The features and specifications of the ...

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CCD riddle: a) signal vs time: linear; b) signal vs variance: non-linear

Cited by 50 publications

References 3 publications

Study of distortions in statistics of counts in CCD observations using the fano factor

Study of distortions in statistics of counts in CCD observations using the fano factor

Design and characterization of specMACS, a multipurpose hyperspectral cloud and sky imager

Electro-optical testing of fully depleted CCD image sensors for the Large Synoptic Survey Telescope camera

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