Design of a coded aperture Compton telescope imaging system (CACTIS)

2010 ◽  
Author(s):  
Alexander Volkovskii ◽  
Martin Clajus ◽  
Stephen R. Gottesman ◽  
Hans Malik ◽  
Kenneth Schwartz ◽  
...  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Angika Bulbul ◽  
Joseph Rosen

AbstractPartial aperture imaging system (PAIS) is a recently developed concept in which the traditional disc-shaped aperture is replaced by an aperture with a much smaller area and yet its imaging capabilities are comparable to the full aperture systems. Recently PAIS was demonstrated as an indirect incoherent digital three-dimensional imaging technique. Later it was successfully implemented in the study of the synthetic marginal aperture with revolving telescopes (SMART) to provide superresolution with subaperture area that was less than one percent of the area of the full synthetic disc-shaped aperture. In the study of SMART, the concept of PAIS was tested by placing eight coded phase reflectors along the boundary of the full synthetic aperture. In the current study, various improvements of PAIS are tested and its performance is compared with the other equivalent systems. Among the structural changes, we test ring-shaped eight coded phase subapertures with the same area as of the previous circular subapertures, distributed along the boundary of the full disc-shaped aperture. Another change in the current system is the use of coded phase mask with a point response of a sparse dot pattern. The third change is in the reconstruction process in which a nonlinear correlation with optimal parameters is implemented. With the improved image quality, the modified-PAIS can save weight and cost of imaging devices in general and of space telescopes in particular. Experimental results with reflective objects show that the concept of coded aperture extends the limits of classical imaging.


2007 ◽  
Author(s):  
A. Mahalanobis ◽  
C. Reyner ◽  
H. Patel ◽  
T. Haberfelde ◽  
David Brady ◽  
...  

2021 ◽  
Vol 2112 (1) ◽  
pp. 012021
Author(s):  
Chong Song ◽  
Lipeng Huo ◽  
Yong Huang ◽  
Yangdong Yan ◽  
Gang Wang ◽  
...  

Abstract Based on the optical system characteristics of coded aperture snapshot spectral imager (CASSI), an optimized optical system of shortwave infrared dual camera CASSI was designed based on improved Offner-Wynne imaging spectrometer. The operating wavelength of the optical system ranges from 900nm to 1700nm, and the focal length is 1200mm. It consists of two parts: the two dimensional imaging system and the multispectral CASSI imaging system. The key technical parameters of the two parts are the same and there is no visual axis difference. Therefore, the optimized optical system can effectively improve real-time performance, optical transmittance and compactness of the dual camera shortwave infrared CASSI, which is conducive to the application in optical measurement scenes in the shooting range.


2013 ◽  
Author(s):  
Anuj J. Kapadia ◽  
Manu N. Lakshmanan ◽  
Kalyani Krishnamurthy ◽  
Pooyan Sahbaee ◽  
Amarpreet Chawla ◽  
...  

2010 ◽  
Author(s):  
Charlotte R. Bennett ◽  
Kevin D. Ridley ◽  
Geoff D. de Villiers ◽  
Philip J. Watson ◽  
Christopher W. Slinger ◽  
...  

Author(s):  
P. R. T. Munro ◽  
M. Endrizzi ◽  
P. C. Diemoz ◽  
C. K. Hagen ◽  
M. B. Szafraniec ◽  
...  

The principal limitation to the widespread deployment of X-ray phase imaging in a variety of applications is probably versatility. A versatile X-ray phase imaging system must be able to work with polychromatic and non-microfocus sources (for example, those currently used in medical and industrial applications), have physical dimensions sufficiently large to accommodate samples of interest, be insensitive to environmental disturbances (such as vibrations and temperature variations), require only simple system set-up and maintenance, and be able to perform quantitative imaging. The coded-aperture technique, based upon the edge illumination principle, satisfies each of these criteria. To date, we have applied the technique to mammography, materials science, small-animal imaging, non-destructive testing and security. In this paper, we outline the theory of coded-aperture phase imaging and show an example of how the technique may be applied to imaging samples with a practically important scale.


2002 ◽  
Vol 1 (4) ◽  
pp. 153535002002213
Author(s):  
Dawid Schellingerhout ◽  
Roberto Accorsi ◽  
Umar Mahmood ◽  
John Idoine ◽  
Richard C. Lanza ◽  
...  

We introduce and demonstrate the utility of coded aperture (CA) nuclear scintigraphy for imaging small animals. CA imaging uses multiple pinholes in a carefully designed mask pattern, mounted on a conventional gamma camera. System performance was assessed using point sources and phantoms, while several animal experiments were performed to test the usefulness of the imaging system in vivo, with commonly used radiopharmaceuticals. The sensitivity of the CA system for 99mTc was 4.2 × 103 cps/Bq (9400 cpm/μCi), compared to 4.4 × 104 cps/Bq (990 cpm/μCi) for a conventional collimator system. The system resolution was 1.7 mm, as compared to 4–6 mm for the conventional imaging system (using a high-sensitivity low-energy collimator). Animal imaging demonstrated artifact-free imaging with superior resolution and image quality compared to conventional collimator images in several mouse and rat models. We conclude that: (a) CA imaging is a useful nuclear imaging technique for small animal imaging. The advantage in signal-to-noise can be traded to achieve higher resolution, decreased dose or reduced imaging time. (b) CA imaging works best for images where activity is concentrated in small volumes; a low count outline may be better demonstrated using conventional collimator imaging. Thus, CA imaging should be viewed as a technique to complement rather than replace traditional nuclear imaging methods. (c) CA hardware and software can be readily adapted to existing gamma cameras, making their implementation a relatively inexpensive retrofit to most systems.


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