Signal to noise ratio in speckle interferometry in the photon counting autocorrelation mode at low light levels

1979 ◽  
Vol 29 (3) ◽  
pp. 273-278 ◽  
Author(s):  
J.G. Walker
Keyword(s):  
Signal To Noise Ratio ◽  
Photon Counting ◽  
Speckle Interferometry ◽  
Signal To Noise ◽  
Low Light ◽  
Light Levels ◽  
Noise Ratio

scholarly journals The Optimal Synapse for Sparse, Binary Signals in the Rod Pathway

2006 ◽  
Vol 18 (1) ◽  
pp. 26-44 ◽  
Author(s):  
Paul T. Clark ◽  
Mark C. W. van Rossum
Keyword(s):  
Transfer Function ◽  
Signal To Noise Ratio ◽  
Bipolar Cells ◽  
Signal To Noise ◽  
Low Light ◽  
Rod Photoreceptors ◽  
Light Levels ◽  
Noise Ratio ◽  
Simulated Images ◽  
Rod Bipolar Cells

The sparsity of photons at very low light levels necessitates a nonlinear synaptic transfer function between the rod photoreceptors and the rod-bipolar cells. We examine different ways to characterize the performance of the pathway: the error rate, two variants of the mutual information, and the signal-to-noise ratio. Simulation of the pathway shows that these approaches yield substantially different performance at very low light levels and that maximizing the signal-to-noise ratio yields the best performance when judged from simulated images. The results are compared to recent data.

LIGHT ADAPTATION AND RELIABILITY IN BLOWFLY PHOTORECEPTORS

1996 ◽  
Vol 07 (04) ◽  
pp. 437-444 ◽  
Author(s):  
R.R. DE RUYTER VAN STEVENINCK ◽  
S.B. LAUGHLIN
Keyword(s):  
Light Adaptation ◽  
Signal To Noise Ratio ◽  
Transduction Efficiency ◽  
Statistical Efficiency ◽  
Signal To Noise ◽  
Low Light ◽  
Frequency Dependent ◽  
Light Levels ◽  
Light Intensities ◽  
Noise Ratio

We characterize the reliability of response of blowfly photoreceptors at different light levels. These cells convey their information by graded potentials. Their reliability is quantified by the frequency-dependent contrast-normalized signal to noise ratio. Independently we estimate the effective photoconversion rate of the cells by counting individual photoconversion events, or quantum bumps, at calibrated low light levels. Comparing both results we quantify the statistical efficiency of photoconversion at higher light intensities, characterizing the transduction efficiency as a function of frequency. The light intensities used in these experiments ranged from about 300 to about 5×105 photoconversions per second per photoreceptor. Over most of this range, statistical efficiencies are within 50% at frequencies up to about 100 Hz.

scholarly journals Three-Dimensional Imaging via Time-Correlated Single-Photon Counting

2020 ◽  
Vol 10 (6) ◽  
pp. 1930
Author(s):  
Chengkun Fu ◽  
Huaibin Zheng ◽  
Gao Wang ◽  
Yu Zhou ◽  
Hui Chen ◽  
...  
Keyword(s):  
3D Imaging ◽  
Single Photon ◽  
Signal To Noise Ratio ◽  
Photon Counting ◽  
Three Dimensional ◽  
Similarity Index ◽  
Signal To Noise ◽  
Single Photon Counting ◽  
Imaging Results ◽  
Noise Ratio

Three-dimensional (3D) imaging under the condition of weak light and low signal-to-noise ratio is a challenging task. In this paper, a 3D imaging scheme based on time-correlated single-photon counting technology is proposed and demonstrated. The 3D imaging scheme, which is composed of a pulsed laser, a scanning mirror, single-photon detectors, and a time-correlated single-photon counting module, employs time-correlated single-photon counting technology for 3D LiDAR (Light Detection and Ranging). Aided by the range-gated technology, experiments show that the proposed scheme can image the object when the signal-to-noise ratio is decreased to −13 dB and improve the structural similarity index of imaging results by 10 times. Then we prove the proposed scheme can image the object in three dimensions with a lateral imaging resolution of 512 × 512 and an axial resolution of 4.2 mm in 6.7 s. At last, a high-resolution 3D reconstruction of an object is also achieved by using the photometric stereo algorithm.

scholarly journals The Signal to Noise Ratio in Speckle Interferometry

1979 ◽  
Vol 50 ◽  
pp. 23-1-23-18 ◽  
Author(s):  
J.C. Dainty ◽  
A.H. Greenaway
Keyword(s):  
Power Spectrum ◽  
Signal To Noise Ratio ◽  
Binary Star ◽  
Image Plane ◽  
Light Level ◽  
Speckle Interferometry ◽  
Signal To Noise ◽  
Speckle Image ◽  
Auto Correlation Function ◽  
Noise Ratio

AbstractRecent theoretical studies of the signal to noise ratio (SNR) of photon limited speckle (image plane) interferometry are reviewed. The SNR of an estimate of the object power spectrum is evaluated for both the single and double aperture cases, for arbitrary light levels. The SNR for the auto-correlation function method of analysis is also given for the low light level case and applied to the special case of binary star observations. The SNRs for the power spectrum and autocorrelation function analyses are compared and a comparison is also made between speckle (image plane) and amplitude (pupil or aperture plane) interferometry. Limiting observable magnitudes are estimated for some relevant cases.

Coincidence Photon-Counting Laser Ranging for Moving Targets With High Signal-to-Noise Ratio

2014 ◽  
Vol 26 (15) ◽  
pp. 1495-1498 ◽  
Author(s):  
Zeyu Bao ◽  
Zhaohui Li ◽  
Yafan Shi ◽  
E. Wu ◽  
Guang Wu ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Photon Counting ◽  
Laser Ranging ◽  
High Signal ◽  
Moving Targets ◽  
Signal To Noise ◽  
Noise Ratio
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