MTF and integration time versus fill factor for sparse-aperture imaging systems

2000 ◽  
Author(s):  
James R. Fienup
Keyword(s):  
Fill Factor ◽  
Imaging Systems ◽  
Integration Time ◽  
Sparse Aperture

Increasing mid-frequency contrast in sparse aperture optical imaging systems

2009 ◽  
Author(s):  
Andrew J. Stokes ◽  
Bradley D. Duncan ◽  
Matthew P. Dierking ◽  
Nicholas J. Miller
Keyword(s):  
Optical Imaging ◽  
Imaging Systems ◽  
Sparse Aperture

Off-axis sparse aperture imaging using phase optimization techniques for application in wide-area imaging systems

2009 ◽  
Vol 48 (28) ◽  
pp. 5212 ◽  
Author(s):  
Abhijit Mahalanobis ◽  
Mark Neifeld ◽  
Vijaya Kumar Bhagavatula ◽  
Thomas Haberfelde ◽  
David Brady
Keyword(s):  
Optimization Techniques ◽  
Imaging Systems ◽  
Wide Area ◽  
Sparse Aperture ◽  
Phase Optimization

Design and implementation of sparse aperture imaging systems

2002 ◽  
Author(s):  
Soon-Jo Chung ◽  
David W. Miller ◽  
Olivier L. de Weck
Keyword(s):  
Imaging Systems ◽  
Design And Implementation ◽  
Sparse Aperture

scholarly journals Improving mid-frequency contrast in sparse aperture optical imaging systems based upon the Golay-9 array

2010 ◽  
Vol 18 (5) ◽  
pp. 4417 ◽  
Author(s):  
Andrew J Stokes ◽  
Bradley D. Duncan ◽  
Mathew P. Dierking
Keyword(s):  
Optical Imaging ◽  
Imaging Systems ◽  
Sparse Aperture

Modelling and impact of the turbulence effect on flash and cumulative 2D active imaging system

2019 ◽  
Vol 8 (6) ◽  
pp. 451-460
Author(s):  
Olivier Meyer
Keyword(s):  
Near Infrared ◽  
Imaging System ◽  
Time Integration ◽  
Imaging Systems ◽  
Intense Laser ◽  
Integration Time ◽  
Level Energy ◽  
Swir Band ◽  
Long Time ◽  
Active Imaging

Abstract In the topic of 2D active imaging systems, two technologies exist for image acquisition. The flash mode consists of a very short and intense laser shot, associated with a short time integration of the sensor (range of hundreds of nanoseconds). The second is the cumulative mode which consists of the integration of many low level energy laser pulses over a long-time integration of the sensor (range of tens of milliseconds). Cumulative mode systems have existed for a long time in the near infrared band. But for the past few years, new sensors are available in the short wave infrared (SWIR) band. Cumulative mode in the SWIR band can provide 2D active imaging systems with very low risk considering the eye safety aspects. Moreover, with a similar design, cumulative systems can overcome the range of flash systems, thanks to their ability to average turbulence effects over the sensor integration time. So, in this paper we have proposed a scintillation noise comparison for each mode. First, we exposed the two types of available models, a numerical model, used for image generation. Second one, an analytical model, used for a quick evaluation of the design of a 2D active imaging system. Both models were compared, especially in their area of validity. Then for a specific scenario, we estimated the gain in term of range performance between a cumulative and a flash system.

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

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