The effect of photon counting detector blocking on centroiding for deep space optical communications

2018 ◽  
Author(s):  
Meera Srinivasan ◽  
Erik Alerstam ◽  
Kenneth Andrews ◽  
Andre Wong
Keyword(s):  
Optical Communications ◽  
Photon Counting ◽  
Deep Space ◽  
Photon Counting Detector

Photon counting detector array algorithms for deep space optical communications

2016 ◽  
Author(s):  
Meera Srinivasan ◽  
Kenneth S. Andrews ◽  
William H. Farr ◽  
Andre Wong
Keyword(s):  
Optical Communications ◽  
Photon Counting ◽  
Detector Array ◽  
Deep Space ◽  
Photon Counting Detector

scholarly journals Signal Acquisition with Photon-Counting Detector Arrays in Free-Space Optical Communications

2019 ◽  
Author(s):  
Muhammad Bashir ◽  
Mohamed-Slim Alouini
Keyword(s):  
False Alarm ◽  
Optical Communications ◽  
Upper Bound ◽  
Free Space ◽  
Photon Counting ◽  
Acquisition Time ◽  
Beam Radius ◽  
Free Space Optical ◽  
Detector Arrays ◽  
Photon Counting Detector

Pointing and acquisition are an important aspect of free-space optical communications because of the narrow beamwidth associated with the optical signal. In this paper, we have analyzed the pointing and acquisition problem in free-space optical communications for photon-counting detector arrays and Gaussian beams. In this regard, we have considered the maximum likelihood detection for detecting the location of the array, and analyzed the one-shot probabilities of missed detection and false alarm using the scaled Poisson approximation. Moreover, the upper/lower bounds on the probabilities of missed detection and false alarm for one complete scan are also derived, and these probabilities are compared with Monte Carlo approximations for a few cases. Additionally, the upper bounds on the acquisition time and the mean acquisition time are also derived. The upper bound on mean acquisition time is minimized numerically with respect to the beam radius for a constant signal-to-noise ratio scenario. Finally, the complementary distribution function of an upper bound on acquisition time is also calculated in a closed form. Our study concludes that an array of smaller detectors gives a better acquisition performance (in terms of acquisition time) as compared to one large detector of similar dimensions as the array. <br>

scholarly journals Signal Acquisition with Photon-Counting Detector Arrays in Free-Space Optical Communications

2019 ◽  
Author(s):  
Muhammad Bashir ◽  
Mohamed-Slim Alouini
Keyword(s):  
False Alarm ◽  
Optical Communications ◽  
Upper Bound ◽  
Free Space ◽  
Photon Counting ◽  
Acquisition Time ◽  
Beam Radius ◽  
Free Space Optical ◽  
Detector Arrays ◽  
Photon Counting Detector

Pointing and acquisition are an important aspect of free-space optical communications because of the narrow beamwidth associated with the optical signal. In this paper, we have analyzed the pointing and acquisition problem in free-space optical communications for photon-counting detector arrays and Gaussian beams. In this regard, we have considered the maximum likelihood detection for detecting the location of the array, and analyzed the one-shot probabilities of missed detection and false alarm using the scaled Poisson approximation. Moreover, the upper/lower bounds on the probabilities of missed detection and false alarm for one complete scan are also derived, and these probabilities are compared with Monte Carlo approximations for a few cases. Additionally, the upper bounds on the acquisition time and the mean acquisition time are also derived. The upper bound on mean acquisition time is minimized numerically with respect to the beam radius for a constant signal-to-noise ratio scenario. Finally, the complementary distribution function of an upper bound on acquisition time is also calculated in a closed form. Our study concludes that an array of smaller detectors gives a better acquisition performance (in terms of acquisition time) as compared to one large detector of similar dimensions as the array. <br>

A Novel Turbo Coded Modulation Scheme for Deep Space Optical Communications

2010 ◽  
Vol E93.B (5) ◽  
pp. 1260-1263 ◽  
Author(s):  
Sangmok OH ◽  
Inho HWANG ◽  
Adrish BANERJEE ◽  
Jeong Woo LEE
Keyword(s):  
Optical Communications ◽  
Coded Modulation ◽  
Modulation Scheme ◽  
Deep Space ◽  
Turbo Coded Modulation

scholarly journals Quantitative dual contrast photon-counting computed tomography for assessment of articular cartilage health

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Petri Paakkari ◽  
Satu I. Inkinen ◽  
Miitu K. M. Honkanen ◽  
Mithilesh Prakash ◽  
Rubina Shaikh ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Articular Cartilage ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Photon Counting ◽  
Spectral Imaging ◽  
Ct Scanning ◽  
Photon Counting Detector ◽  
Tissue Contrast ◽  
Reference Parameters

AbstractPhoton-counting detector computed tomography (PCD-CT) is a modern spectral imaging technique utilizing photon-counting detectors (PCDs). PCDs detect individual photons and classify them into fixed energy bins, thus enabling energy selective imaging, contrary to energy integrating detectors that detects and sums the total energy from all photons during acquisition. The structure and composition of the articular cartilage cannot be detected with native CT imaging but can be assessed using contrast-enhancement. Spectral imaging allows simultaneous decomposition of multiple contrast agents, which can be used to target and highlight discrete cartilage properties. Here we report, for the first time, the use of PCD-CT to quantify a cationic iodinated CA4+ (targeting proteoglycans) and a non-ionic gadolinium-based gadoteridol (reflecting water content) contrast agents inside human osteochondral tissue (n = 53). We performed PCD-CT scanning at diffusion equilibrium and compared the results against reference data of biomechanical and optical density measurements, and Mankin scoring. PCD-CT enables simultaneous quantification of the two contrast agent concentrations inside cartilage and the results correlate with the structural and functional reference parameters. With improved soft tissue contrast and assessment of proteoglycan and water contents, PCD-CT with the dual contrast agent method is of potential use for the detection and monitoring of osteoarthritis.

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