Microscopic Models of Photodetection

Selloni, Annabella

doi:10.1007/978-3-642-81472-3_4

Cited by 4 publications

(1 citation statement)

References 72 publications

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“…Previous studies have been made of such afterpulsing and dead-time effects (e.g., Foord et al 1969[but see comments by Young 1971b; Gadsen 1965; Gulari and Chu 1978;Saleh 1978;Young 1974), which may influence the details in measured statistical distributions (e.g., Apanasovich and Paltsev 1995;Campbell 1992;Jakeman and Pusey 1980;Selloni 1980;Strohbehn et al 1975).…”

Section: A3 Detector Propertiesmentioning

confidence: 99%

Atmospheric Intensity Scintillation of Stars, I. Statistical Distributions and Temporal Properties

Dravins¹,

Lindegren²,

Mezey³

et al. 1997

PASP

102

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Stellar intensity scintillation in the optical was extensively studied at the astronomical observatory on La Palma (Canary Islands). Photon-counting detectors and digital signal processors recorded temporal auto-and cross-correlation functions, power spectra, and probability distributions. This first paper of a series treats the temporal properties of scintillation, ranging from microseconds to seasons of year. Previous studies, and the mechanisms producing scintillation are reviewed. Atmospheric turbulence causes 'flying shadows' on the ground, and intensity fluctuations occur both because this pattern is carried by winds, and is intrinsically changing. On very short time scales, a break in the correlation functions around 300 ¡¿s may be a signature of an inner scale (=3 mm in the shadow pattern at wind speeds of 10 m s -1 ). On millisecond time scales, the autocorrelation halfwidth decreases for smaller telescope apertures until -5 cm, when the 'flying shadows' become resolved. During any night, time scales and amplitudes evolve on scales of tens of minutes. In good summer conditions, the flying-shadow patterns are sufficiently regular and long-lived to show anti-correlation dips in autocorrelation functions, which in winter are smeared out by apparent wind shear. Recordings of intensity variance together with stellar speckle images suggest some correlation between good (angular) seeing and large scintillation. Near zenith, the temporal statistics (with up to twelfth-order moments measured) is best fitted by a Beta distribution of the second kind (F-distribution), although it is well approximated by log-normal functions, evolving with time.

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