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Pulse versus CW laser line scan imaging detection methods: simulation results

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Date Issued:
2007
Title: Pulse versus CW laser line scan imaging detection methods: simulation results.
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Name(s): Caimi, F. M., creator
Dalgleish, Fraser R., creator
Giddings, T. E., creator
Shirron, J. J., creator
Mazel, C. H., creator
Chiang, K., creator
Type of Resource: text
Genre: Article
Issuance: single unit
Date Issued: 2007
Publisher: IEEE
Extent: 5 p.
Physical Description: pdf
Language(s): English
Identifier: 1927694 (digitool), FADT1927694 (IID), fau:5477 (fedora), 10.1109/oceanse.2007.4302476 (doi)
Note(s): Laser Line Scan (LLS) systems rely upon narrow angular field apertures and displacement between emitter and receiver to reduce volume backscatter from the common volume near the target. With this configuration, multiple volume scattering near the sensor becomes a significant contribution to the total backscatter return. Detection of continuous wave laser return signals is complicated at the range limit of these systems due to the temporal overlap between the target return and the backscatter return. In the compact implementation of these systems, necessary when the deployment platform is the 12" or 21" diameter AUV, this detection ambiguity can lead to a significant degradation in imaging performance. Detection methods must therefore separate the two signals and estimate the energy returning from the target alone. Indeed, the use of pulsed laser illumination under some conditions allows for temporal separation of the target and volume scattering return signals. However, this method relies upon knowledge of the target distance and establishment of a gated detection scheme. We present a comparison of simulation results for both the CW and pulsed-laser cases in a range of turbid water conditions and at differing optical attenuation lengths approaching the limiting case for these types of underwater imagers. These simulations are performed using models developed by Metron Inc. (Reston, VA), and allow both a time history and image quality comparison. The goal of this simulation work is to identify the operational and environmental conditions under which each scheme is usable for the AUV-deployed scenario. Experimental results supporting these findings will be presented as available. (This work was conducted under a grant monitored by the US Office of Naval Research).
IEEE publications are available online at http://www.ieee.org/ this article should be cited as Caimi, F.M., Dalgleish, F. R., Giddings, T. E. Shirron, J. J., Mazel, C. H., Chiang, K. (2007) Pulse versus CW laser line scan imaging detection methods: simulation results, Marine Technology Society, Proc. MTS/IEEE Oceans Europe 2007, Aberdeen, Scotland.
Florida Atlantic University. Harbor Branch Oceanographic Institute contribution #1740.
Subject(s): Underwater imaging systems
Laser beams --Scattering
Persistent Link to This Record: http://purl.flvc.org/FCLA/DT/1927694
Links: https://doi.org/10.1109/oceanse.2007.4302476 
Restrictions on Access: ©2007 Marine Technology Society, IEEE
Host Institution: FAU