Abstract

It is a well-known fact that the major degradation source on electro-optical imaging underwater is from scattering by particles of various origins and sizes. Recent research indicates that, under certain conditions, the apparent degradation could also be caused by the variations of index of refraction associated with temperature and salinity microstructures in the ocean and lakes. The combined impact has been modeled previously through the simple underwater imaging model. The current study presents the first attempts in quantifying the level of image degradation due to optical turbulence in natural waters in terms of modulation transfer functions using measured turbulence dissipation rates. Image data collected from natural environments during the Skaneateles Optical Turbulence Exercise are presented. Accurate assessments of the turbulence conditions are critical to the model validation and were measured by two instruments to ensure consistency and accuracy. Optical properties of the water column in the field were also measured in coordination with temperature, conductivity, and depth. The results show that optical turbulence degrades the image quality as predicted and on a level comparable to that caused by the particle scattering just above the thermocline. Other contributing elements involving model closure, including temporal and spatial measurement scale differences among sensors and mitigation efforts, are discussed.

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References

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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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2011

W. Hou, S. Woods, W. Goode, E. Jarosz, and A. Weidemann, “Impacts of optical turbulence on underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

S. Woods, W. Hou, W. Goode, E. Jarosz, and A. Weidemann, “Quantifying turbulence microstructure for improvement of underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

A. Kanaev, W. Hou, and S. Woods, “Multi-frame underwater image restoration,” Proc. SPIE 8185, 818500 (2011).
[CrossRef]

2009

2008

2007

W. Hou, Z. Lee, and A. Weidemann, “Why does the Secchi disk disappear? An imaging perspective,” Opt. Express 15, 2791–2802 (2007).
[CrossRef]

G. Potvin, J. L. Forand, and D. Dion, “Some theoretical aspects of the turbulent point-spread function,” Appl. Opt. 24, 2932–2942 (2007).
[CrossRef]

W. Hou, A. Weidemann, D. Gray, and G. R. Fournier, “Imagery-derived modulation transfer function and its applications for underwater imaging,” Proc. SPIE 6696, 6696221(2007).
[CrossRef]

2004

2003

1997

Y. Yitzhaky, I. Dror, and N. Kopeika, “Restoration of atmospherically blurred images according to weather-predicted atmospheric modulation transfer functions,” Opt. Eng. 36, 3064–3072 (1997).
[CrossRef]

1994

D. Sadot, A. Dvir, I. Bergel, and N. Kopeika, “Restoration of thermal images distorted by the atmosphere, based on measured and theoretical atmospheric modulation transfer function,” Opt. Eng. 33, 44–53 (1994).
[CrossRef]

1993

G. R. Fournier, D. Bonnier, J. L. Forand, and P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

1987

N. Kopeika, “Imaging through the atmosphere for airborne reconnaissance,” Opt. Eng. 26, 1146–1154 (1987).
[CrossRef]

I. A. Cunningham and A. Fenster, “A method for modulation transfer function determination from edge profiles with correction for finite-element differentiation,” Med. Phys. 14, (1987).
[CrossRef]

1967

1966

1959

G. K. Batchelor, “Small-scale variation of convected quantities like temperature in turbulence fluid,” J. Fluid Mech. 5, 113–133 (1959).
[CrossRef]

Arnone, R.

Batchelor, G. K.

G. K. Batchelor, “Small-scale variation of convected quantities like temperature in turbulence fluid,” J. Fluid Mech. 5, 113–133 (1959).
[CrossRef]

Bergel, I.

D. Sadot, A. Dvir, I. Bergel, and N. Kopeika, “Restoration of thermal images distorted by the atmosphere, based on measured and theoretical atmospheric modulation transfer function,” Opt. Eng. 33, 44–53 (1994).
[CrossRef]

Bogucki, D. J.

Bonnier, D.

G. R. Fournier, D. Bonnier, J. L. Forand, and P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

Chang, P. C.

Concannon, B. M.

Cunningham, I. A.

I. A. Cunningham and A. Fenster, “A method for modulation transfer function determination from edge profiles with correction for finite-element differentiation,” Med. Phys. 14, (1987).
[CrossRef]

Dion, D.

G. Potvin, J. L. Forand, and D. Dion, “Some theoretical aspects of the turbulent point-spread function,” Appl. Opt. 24, 2932–2942 (2007).
[CrossRef]

Domaradzki, J. A.

Dror, I.

Y. Yitzhaky, I. Dror, and N. Kopeika, “Restoration of atmospherically blurred images according to weather-predicted atmospheric modulation transfer functions,” Opt. Eng. 36, 3064–3072 (1997).
[CrossRef]

Dvir, A.

D. Sadot, A. Dvir, I. Bergel, and N. Kopeika, “Restoration of thermal images distorted by the atmosphere, based on measured and theoretical atmospheric modulation transfer function,” Opt. Eng. 33, 44–53 (1994).
[CrossRef]

Ecke, R. E.

Effler, S. W.

S. W. Effler, A. R. Prestigiacomo, and D. M. O’Donnel, “Water quality and limnological monitoring for Skaneateles Lake: field year 2007” (Upstate Freshwater Institute, 2008), p. 57.

Fenster, A.

I. A. Cunningham and A. Fenster, “A method for modulation transfer function determination from edge profiles with correction for finite-element differentiation,” Med. Phys. 14, (1987).
[CrossRef]

Flitton, J. C.

Forand, J. L.

G. Potvin, J. L. Forand, and D. Dion, “Some theoretical aspects of the turbulent point-spread function,” Appl. Opt. 24, 2932–2942 (2007).
[CrossRef]

G. R. Fournier, D. Bonnier, J. L. Forand, and P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

Fournier, G. R.

W. Hou, A. Weidemann, D. Gray, and G. R. Fournier, “Imagery-derived modulation transfer function and its applications for underwater imaging,” Proc. SPIE 6696, 6696221(2007).
[CrossRef]

G. R. Fournier, D. Bonnier, J. L. Forand, and P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

Fried, D. L.

Gilbert, G. D.

G. D. Gilbert and J. C. Pernicka, “Improvement of underwater visibility by reduction of backscatter with a circular polarization technique,” Appl. Opt. 6, 741–746 (1967).
[CrossRef]

G. D. Gilbert and R. C. Honey, “Optical turbulence in the sea,” in Underwater Photo-optical Instrumentation Applications (SPIE, 1972), pp. 49–55.

Goode, W.

S. Woods, W. Hou, W. Goode, E. Jarosz, and A. Weidemann, “Quantifying turbulence microstructure for improvement of underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

W. Hou, S. Woods, W. Goode, E. Jarosz, and A. Weidemann, “Impacts of optical turbulence on underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

S. Woods, Naval Research Laboratory, Stennis Space Center, MS 39529, USA, W. Hou, E. Jarosz, W. Goode, and A. Weidemann are preparing a manuscript be called “Measurements of turbulence dissipation in Lake Skeneateles.”

Gray, D.

W. Hou, D. Gray, A. Weidemann, and R. Arnone, “Comparison and validation of point spread models for imaging in natural waters,” Opt. Express 16, 9958–9965 (2008).
[CrossRef]

W. Hou, A. Weidemann, D. Gray, and G. R. Fournier, “Imagery-derived modulation transfer function and its applications for underwater imaging,” Proc. SPIE 6696, 6696221(2007).
[CrossRef]

Honey, R. C.

G. D. Gilbert and R. C. Honey, “Optical turbulence in the sea,” in Underwater Photo-optical Instrumentation Applications (SPIE, 1972), pp. 49–55.

Hopcraft, K. I.

Hou, W.

W. Hou, S. Woods, W. Goode, E. Jarosz, and A. Weidemann, “Impacts of optical turbulence on underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

S. Woods, W. Hou, W. Goode, E. Jarosz, and A. Weidemann, “Quantifying turbulence microstructure for improvement of underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

A. Kanaev, W. Hou, and S. Woods, “Multi-frame underwater image restoration,” Proc. SPIE 8185, 818500 (2011).
[CrossRef]

W. Hou, “A simple underwater imaging model,” Opt. Lett. 34, 2688–2690 (2009).
[CrossRef]

W. Hou, D. Gray, A. Weidemann, and R. Arnone, “Comparison and validation of point spread models for imaging in natural waters,” Opt. Express 16, 9958–9965 (2008).
[CrossRef]

W. Hou, Z. Lee, and A. Weidemann, “Why does the Secchi disk disappear? An imaging perspective,” Opt. Express 15, 2791–2802 (2007).
[CrossRef]

W. Hou, A. Weidemann, D. Gray, and G. R. Fournier, “Imagery-derived modulation transfer function and its applications for underwater imaging,” Proc. SPIE 6696, 6696221(2007).
[CrossRef]

W. Hou, “Characteristics of large particles and their effects on submarine light field,” Ph.D. dissertation (University of South Florida, 1997), p. 149.

S. Woods, Naval Research Laboratory, Stennis Space Center, MS 39529, USA, W. Hou, E. Jarosz, W. Goode, and A. Weidemann are preparing a manuscript be called “Measurements of turbulence dissipation in Lake Skeneateles.”

Jakeman, E.

Jarosz, E.

W. Hou, S. Woods, W. Goode, E. Jarosz, and A. Weidemann, “Impacts of optical turbulence on underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

S. Woods, W. Hou, W. Goode, E. Jarosz, and A. Weidemann, “Quantifying turbulence microstructure for improvement of underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

S. Woods, Naval Research Laboratory, Stennis Space Center, MS 39529, USA, W. Hou, E. Jarosz, W. Goode, and A. Weidemann are preparing a manuscript be called “Measurements of turbulence dissipation in Lake Skeneateles.”

Jordan, D. L.

Kanaev, A.

A. Kanaev, W. Hou, and S. Woods, “Multi-frame underwater image restoration,” Proc. SPIE 8185, 818500 (2011).
[CrossRef]

Katsev, I. L.

Kopeika, N.

Y. Yitzhaky, I. Dror, and N. Kopeika, “Restoration of atmospherically blurred images according to weather-predicted atmospheric modulation transfer functions,” Opt. Eng. 36, 3064–3072 (1997).
[CrossRef]

D. Sadot, A. Dvir, I. Bergel, and N. Kopeika, “Restoration of thermal images distorted by the atmosphere, based on measured and theoretical atmospheric modulation transfer function,” Opt. Eng. 33, 44–53 (1994).
[CrossRef]

N. Kopeika, “Imaging through the atmosphere for airborne reconnaissance,” Opt. Eng. 26, 1146–1154 (1987).
[CrossRef]

Laux, A.

Lee, Z.

Mullen, L.

O’Donnel, D. M.

S. W. Effler, A. R. Prestigiacomo, and D. M. O’Donnel, “Water quality and limnological monitoring for Skaneateles Lake: field year 2007” (Upstate Freshwater Institute, 2008), p. 57.

Pace, P. W.

G. R. Fournier, D. Bonnier, J. L. Forand, and P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

Pernicka, J. C.

Potvin, G.

G. Potvin, J. L. Forand, and D. Dion, “Some theoretical aspects of the turbulent point-spread function,” Appl. Opt. 24, 2932–2942 (2007).
[CrossRef]

Prestigiacomo, A. R.

S. W. Effler, A. R. Prestigiacomo, and D. M. O’Donnel, “Water quality and limnological monitoring for Skaneateles Lake: field year 2007” (Upstate Freshwater Institute, 2008), p. 57.

Prikhach, A. S.

Roggemann, M. C.

M. C. Roggemann and B. M. Welsh, Imaging through Turbulence (CRC, 1996).

Sadot, D.

D. Sadot, A. Dvir, I. Bergel, and N. Kopeika, “Restoration of thermal images distorted by the atmosphere, based on measured and theoretical atmospheric modulation transfer function,” Opt. Eng. 33, 44–53 (1994).
[CrossRef]

Truman, C. R.

Walker, J. G.

Weidemann, A.

W. Hou, S. Woods, W. Goode, E. Jarosz, and A. Weidemann, “Impacts of optical turbulence on underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

S. Woods, W. Hou, W. Goode, E. Jarosz, and A. Weidemann, “Quantifying turbulence microstructure for improvement of underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

W. Hou, D. Gray, A. Weidemann, and R. Arnone, “Comparison and validation of point spread models for imaging in natural waters,” Opt. Express 16, 9958–9965 (2008).
[CrossRef]

W. Hou, Z. Lee, and A. Weidemann, “Why does the Secchi disk disappear? An imaging perspective,” Opt. Express 15, 2791–2802 (2007).
[CrossRef]

W. Hou, A. Weidemann, D. Gray, and G. R. Fournier, “Imagery-derived modulation transfer function and its applications for underwater imaging,” Proc. SPIE 6696, 6696221(2007).
[CrossRef]

S. Woods, Naval Research Laboratory, Stennis Space Center, MS 39529, USA, W. Hou, E. Jarosz, W. Goode, and A. Weidemann are preparing a manuscript be called “Measurements of turbulence dissipation in Lake Skeneateles.”

Wells, W. H.

W. H. Wells, “Theory of small angle scattering,” in AGARD Lecture Series (NATO, 1973), Vol. 61.

Welsh, B. M.

M. C. Roggemann and B. M. Welsh, Imaging through Turbulence (CRC, 1996).

Woods, S.

W. Hou, S. Woods, W. Goode, E. Jarosz, and A. Weidemann, “Impacts of optical turbulence on underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

S. Woods, W. Hou, W. Goode, E. Jarosz, and A. Weidemann, “Quantifying turbulence microstructure for improvement of underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

A. Kanaev, W. Hou, and S. Woods, “Multi-frame underwater image restoration,” Proc. SPIE 8185, 818500 (2011).
[CrossRef]

S. Woods, Naval Research Laboratory, Stennis Space Center, MS 39529, USA, W. Hou, E. Jarosz, W. Goode, and A. Weidemann are preparing a manuscript be called “Measurements of turbulence dissipation in Lake Skeneateles.”

Yitzhaky, Y.

Y. Yitzhaky, I. Dror, and N. Kopeika, “Restoration of atmospherically blurred images according to weather-predicted atmospheric modulation transfer functions,” Opt. Eng. 36, 3064–3072 (1997).
[CrossRef]

Zege, E. P.

Appl. Opt.

J. Fluid Mech.

G. K. Batchelor, “Small-scale variation of convected quantities like temperature in turbulence fluid,” J. Fluid Mech. 5, 113–133 (1959).
[CrossRef]

J. Opt. Soc. Am.

Med. Phys.

I. A. Cunningham and A. Fenster, “A method for modulation transfer function determination from edge profiles with correction for finite-element differentiation,” Med. Phys. 14, (1987).
[CrossRef]

Opt. Eng.

G. R. Fournier, D. Bonnier, J. L. Forand, and P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

N. Kopeika, “Imaging through the atmosphere for airborne reconnaissance,” Opt. Eng. 26, 1146–1154 (1987).
[CrossRef]

D. Sadot, A. Dvir, I. Bergel, and N. Kopeika, “Restoration of thermal images distorted by the atmosphere, based on measured and theoretical atmospheric modulation transfer function,” Opt. Eng. 33, 44–53 (1994).
[CrossRef]

Y. Yitzhaky, I. Dror, and N. Kopeika, “Restoration of atmospherically blurred images according to weather-predicted atmospheric modulation transfer functions,” Opt. Eng. 36, 3064–3072 (1997).
[CrossRef]

Opt. Express

Opt. Lett.

Proc. SPIE

W. Hou, A. Weidemann, D. Gray, and G. R. Fournier, “Imagery-derived modulation transfer function and its applications for underwater imaging,” Proc. SPIE 6696, 6696221(2007).
[CrossRef]

W. Hou, S. Woods, W. Goode, E. Jarosz, and A. Weidemann, “Impacts of optical turbulence on underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

S. Woods, W. Hou, W. Goode, E. Jarosz, and A. Weidemann, “Quantifying turbulence microstructure for improvement of underwater imaging,” Proc. SPIE 8030, 883009 (2011).
[CrossRef]

A. Kanaev, W. Hou, and S. Woods, “Multi-frame underwater image restoration,” Proc. SPIE 8185, 818500 (2011).
[CrossRef]

Other

ISO, “Electronic still picture imaging spatial frequency response (SFR) measurements” (International Organisation for Standardization, 1997).

G. D. Gilbert and R. C. Honey, “Optical turbulence in the sea,” in Underwater Photo-optical Instrumentation Applications (SPIE, 1972), pp. 49–55.

W. Hou, “Characteristics of large particles and their effects on submarine light field,” Ph.D. dissertation (University of South Florida, 1997), p. 149.

M. C. Roggemann and B. M. Welsh, Imaging through Turbulence (CRC, 1996).

S. W. Effler, A. R. Prestigiacomo, and D. M. O’Donnel, “Water quality and limnological monitoring for Skaneateles Lake: field year 2007” (Upstate Freshwater Institute, 2008), p. 57.

S. Woods, Naval Research Laboratory, Stennis Space Center, MS 39529, USA, W. Hou, E. Jarosz, W. Goode, and A. Weidemann are preparing a manuscript be called “Measurements of turbulence dissipation in Lake Skeneateles.”

W. H. Wells, “Theory of small angle scattering,” in AGARD Lecture Series (NATO, 1973), Vol. 61.

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Figures (8)

Fig. 1.
Fig. 1.

Bathymetric sketch of Skaneateles Lake showing the approximate location of the two stations: S1 (red circle) near the center of the lake, and S2 (blue triangle) in the northern end of the lake. Map from http://www.ourlake.org/html/skaneateles_lake1.html.

Fig. 2.
Fig. 2.

Optical properties (beam-c at 532 nm) and temperature profile measured during July 27 daytime IMAST deployment. Temperature profiles from other deployments are plotted as well to show the stable and strong thermoclines at station 1.

Fig. 3.
Fig. 3.

IMAST night deployment configuration: imaging camera and housing (left end of the frame); active target made out of iPad (right end of the frame). Notice the Vector and CT locations. For details on other sensors, including the Vector, please refer to the text.

Fig. 4.
Fig. 4.

Diagram of deployment setup showing alternate deployment configurations: Vector/CT deployed on IMAST both vertically and horizontally. Note, in both instances, the VMP was deployed from a separate vessel. The intercomparison is necessary in order to measure turbulence impacts during IMAST deployments.

Fig. 5.
Fig. 5.

Sample image pair obtained by IMAST during night deployment (IMAST horizontal) of July 27. The corresponding physical conditions can be seen in Fig. 2 and related publications (see text). (a) The left was taken at 2.8 m depth with no obvious optical turbulence, while (b) the right was from 8.7 m under conditions of similar turbidity but strong optical turbulence. The images share the same imaging path, camera, and light settings. For the current IMAST setting, the 0-2 group corresponds to 1900cycles/rad.

Fig. 6.
Fig. 6.

Normalized MTF of individual (light dashed) and 10-frame averaged (solid line) images obtained under strong (8.7 m) and weak (2.8 m) optical turbulence during SOTEX. MTFs are calculated using slant-edge algorithms over the same ROI for all images. The optical properties (particle scattering) of these images are similar and can be seen in Fig. 2.

Fig. 7.
Fig. 7.

MTFs of three different image sequences estimated from 8.7 m using the slant-edge method, and compared to the modeled results, during July 27 night deployment. (a) The relative variations in MTF of the three image sequences from 8.7 m depth (marked A, B, and C), compared to the averaged value at 2.8 m. (b–d) compare individual sequences at 8.7 m and 2.8 m respectively.

Fig. 8.
Fig. 8.

(a)–(c) MTF model results improved by including contribution from extra particle scattering for each image sequence estimated from the depth of 8.7 m (marked A, B, and C)These are the same image sequences used in Fig. 7 (obtained during July 27 night deployment).

Tables (1)

Tables Icon

Table 1. Key Parameters and Definitions Used in the Paper

Equations (3)

Equations on this page are rendered with MathJax. Learn more.

OTF(ψ,r)total=OTF(ψ,r)pathOTF(ψ,r)parOTF(ψ,r)tur=(11+D)exp[cr+br(1e2πθ0ψ2πθ0ψ)]exp(Snψ5/3r)=(11+D)exp{[cb(1e2πθ0ψ2πθ0ψ)+Snψ5/3]r},
Sn=3.44(λ¯/R0)5/3=1736K3λ¯1/3,
H2(ψ,r)=exp[(Sn2Sn1)ψ5/3r]exp[(c2c1)(1ϖ0(1e2πθ0ψ2πθ0ψ)]H1(ψ,r),

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