Dr. Sarah Woods Profile

Dr. Sarah Woods

ASEE Postdoctoral Researcher at US Naval Research Lab

SPIE Involvement:

Author

Proceedings Article | 3 June 2013 Paper

Measurements of turbulent dissipation during the Bahamas Optical Turbulence Experiment

Silvia Matt, Weilin Hou, Sarah Woods, Ewa Jarosz, Wesley Goode, Alan Weidemann

Proceedings Volume 8724, 872405 (2013) https://doi.org/10.1117/12.2018303

KEYWORDS: Turbulence, Optical turbulence, Temperature metrology, Intelligence systems, Error analysis, Tongue, Velocity measurements, Tin, Ocean optics, Optical properties

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Proceedings Article | 12 June 2012 Paper

Bahamas Optical Turbulence Exercise (BOTEX): preliminary results

Weilin Hou, Ewa Jorosz, Fraser Dalgleish, Gero Nootz, Sarah Woods, Alan Weidemann, Wesley Goode, Anni Vuorenkoski, B. Metzger, B. Ramos

Proceedings Volume 8372, 837206 (2012) https://doi.org/10.1117/12.920740

KEYWORDS: Turbulence, Optical turbulence, Ocean optics, Sensors, Scattering, Imaging systems, Particles, Water, Image transmission, High speed cameras

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The Bahamas Optical Turbulence Exercise (BOTEX) was conducted in the coastal waters of Florida and the Bahamas from June 30 to July 12 2011, onboard the R/V FG Walton Smith. The primary objective of the BOTEX was to obtain field measurements of optical turbulence structures, in order to investigate the impacts of the naturally occurring turbulence on underwater imaging and optical beam propagation. In order to successfully image through optical turbulence structures in the water and examine their impacts on optical transmission, a high speed camera and targets (both active and passive) were mounted on a rigid frame to form the Image Measurement Assembly for Subsurface Turbulence (IMAST). To investigate the impacts on active imaging systems such as the laser line scan (LLS), the Telescoping Rigid Underwater Sensor Structure (TRUSS) was designed and implemented by Harbor Branch Oceanographic Institute. The experiments were designed to determine the resolution limits of LLS systems as a function of turbulence induced beam wander at the target. The impact of natural turbulence structures on lidar backscatter waveforms was also examined, by means of a telescopic receiver and a short pulse transmitter, co-located, on a vertical profiling frame. To include a wide range of water types in terms of optical and physical conditions, data was collected from four different locations. . Impacts from optical turbulence were observed under both strong and weak physical structures. Turbulence measurements were made by two instruments, the Vertical Microstructure Profiler (VMP) and a 3D acoustical Doppler velocimeter with fast conductivity and temperature probes, in close proximity in the field. Subsequently these were mounted on the IMAST during moored deployments. The turbulence kinetic energy dissipation rate and the temperature dissipation rates were calculated from both setups in order to characterize the physical environments and their impacts. Beam deflection by multiple point patterns are examined, using high speed camera recordings (300 to 1200 fps), in association with measured turbulence structures. Initial results confirmed our hypothesis that turbulence impacted optical transmissions. They also showed that more research will be needed to better quantify and mitigate such effects, especially for the U.S. Navy's next generation EO systems, including active imaging, lidar and optical communications.

SPIE Journal Paper | 21 May 2012

Restoration of turbulence degraded underwater images

Andrey Kanaev, Leslie Smith, Weilin Hou, Sarah Woods

OE, Vol. 51, Issue 5, 057007, (May 2012) https://doi.org/10.1117/12.10.1117/1.OE.51.5.057007

KEYWORDS: Optical flow, Image fusion, Turbulence, Algorithm development, Image restoration, Image quality, Image filtering, Spatial frequencies, Reconstruction algorithms, Water

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Proceedings Article | 28 September 2011 Paper

Assessing EO image degradation from underwater optical turbulence in natural waters

Weilin Hou, Andrey Kanaev, Sarah Woods

Proceedings Volume 8185, 81850D (2011) https://doi.org/10.1117/12.897756

KEYWORDS: Turbulence, Optical turbulence, Modulation transfer functions, Water, Scattering, Particles, Image enhancement, Algorithm development, Optical flow, Visibility

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Proceedings Article | 28 September 2011 Paper

Multi-frame underwater image restoration

A. Kanaev, W. Hou, S. Woods

Proceedings Volume 8185, 81850O (2011) https://doi.org/10.1117/12.898914

KEYWORDS: Image fusion, Image restoration, Optical flow, Image quality, Algorithm development, Turbulence, Spatial frequencies, Motion estimation, Underwater imaging, Scattering

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Proceedings Article | 5 May 2011 Paper

Quantifying turbulence microstructure for improvement of underwater imaging

Sarah Woods, Weilin Hou, Wesley Goode, Ewa Jarosz, Alan Weidemann

Proceedings Volume 8030, 80300A (2011) https://doi.org/10.1117/12.887607

KEYWORDS: Turbulence, Scattering, Underwater imaging, Light scattering, Sensors, Visibility, Temperature metrology, Target detection, Optical turbulence, Water

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Proceedings Article | 5 May 2011 Paper

Impacts of optical turbulence on underwater imaging

Weilin Hou, S. Woods, W. Goode, E. Jarosz, A. Weidemann

Proceedings Volume 8030, 803009 (2011) https://doi.org/10.1117/12.883114

KEYWORDS: Turbulence, Modulation transfer functions, Optical turbulence, Scattering, Water, Optical transfer functions, Underwater imaging, Optical properties, Laser scattering, Data modeling

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Showing 5 of 7 publications

Conference Committee Involvement (2)

Ocean Sensing and Monitoring IV

24 April 2012 | Baltimore, Maryland, United States

Ocean Sensing and Monitoring III

26 April 2011 | Orlando, Florida, United States

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