Abstract

A wide-field-of-view white-light imaging experiment with artificially generated turbulence layers located between the extended object and the imaging system is described. Relocation of the turbulence sources along the imaging path allowed the creation of controllable anisoplanatic effects. We demonstrate that the recently proposed synthetic imaging technique [J. Opt. Soc. Am. A 16, 1623 (1999)] may result in substantial improvement in image quality for highly anisoplanatic conditions. It is shown that for multisource objects located at different distances the processing of turbulence-degraded short-exposure images may lead to a synthetic image that has an image quality superior to that of the undistorted image obtained in the absence of turbulence (turbulence-induced image quality enhancement).

© 2001 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. F. Roddier, ed., Adaptive Optics in Astronomy (Cambridge U. Press, Cambridge, UK, 1999), pp. 91–130.
  2. R. Q. Fugate, “Laser beacon adaptive optics,” Opt. Photon. News, pp. 14–19 (June 1994).
  3. M. C. Roggemann, B. M. Welsh, Imaging through Turbulence (CRC Press, Boca Raton, Fla., 1996).
  4. D. L. Fried, “Anisoplanatism in adaptive optics,” J. Opt. Soc. Am. 72, 52–61 (1982).
    [CrossRef]
  5. B. M. Welsh, C. S. Gardner, “Effects of turbulence induced anisoplanatism on the imaging performance of adaptive astronomical telescopes using laser guide stars,” J. Opt. Soc. Am. A 8, 69–80 (1991).
    [CrossRef]
  6. M. I. Chernotskii, “Anisoplanatic short-exposure imaging in turbulence,” J. Opt. Soc. Am. A 10, 492–501 (1993).
    [CrossRef]
  7. D. V. Murphy, C. A. Primmerman, B. G. Zollars, H. T. Barclay, “Experimental demonstration of atmospheric compensation using multiple synthetic beacons.” Opt. Lett. 16, 1797–1799 (1991).
    [CrossRef] [PubMed]
  8. P. L. Wizinowich, ed., Adaptive Optical Systems Technology, Proc. SPIE4007 (2000).
  9. R. G. Paxman, J. R. Fienup, “Optical misalignment sensing and image reconstruction using phase diversity,” J. Opt. Soc. Am. A 5, 914–923 (1988).
    [CrossRef]
  10. R. G. Paxman, B. J. Thelen, J. H. Seldin, “Phase-diversity correction of space-variant turbulence-induced blur,” Opt. Lett. 19, 1231–1233 (1994).
    [CrossRef] [PubMed]
  11. A. Labeyrie, “Attainment of diffraction limited resolution in large telescopes by Fourier analyzing speckle patterns in star images,” Astron. Astrophys. 6, 85 (1970).
  12. J. Primot, G. Rousset, J. C. Fortanella, “Deconvolution from wave-front sensing: a new technique for compensating turbulence-degraded images,” J. Opt. Soc. Am. A 7, 1589–1608 (1990).
    [CrossRef]
  13. R. A. Muller, A. Buffington, “Real-time correction of atmospherically degraded telescope images through image sharpening,” J. Opt. Soc. Am. 64, 1200–1210 (1974).
    [CrossRef]
  14. M. A. Vorontsov, G. W. Carhart, D. V. Pruidze, J. C. Ricklin, D. G. Voelz, “Adaptive imaging system for phase-distorted extended source/multiple distance objects,” Appl. Opt. 36, 3319–3328 (1997); M. A. Vorontsov, G. W. Carhart, M. Cohen, G. Cauwenberghs, “Adaptive optics based on analog parallel stochastic optimization: analysis and experimental demonstration,” J. Opt. Soc. Am. A 17, 1440–1453 (2000).
    [CrossRef] [PubMed]
  15. D. Fraser, G. Thorpe, A. J. Lambert, “Atmospheric turbulence visualization with wide-area motion-blur restoration,” J. Opt. Soc. Am. A 16, 1751–1758 (1999).
    [CrossRef]
  16. D. Fraser, A. J. Lambert, “Wide area image restoration using a new iterative registration method,” in Image Reconstruction From Incomplete Data, M. A. Fiddy, R. P. Millane, eds., Proc. SPIE4123, 64–72 (2000).
    [CrossRef]
  17. D. L. Fried, “Probability of getting a lucky short-exposure image through turbulence,” J. Opt. Soc. Am. 68, 1651–1658 (1978).
    [CrossRef]
  18. M. C. Roggemann, C. A. Stoudt, B. M. Welsh, “Image spectrum signal-to-noise ratio improvement by statistical frame selection for adaptive optics imaging through atmospheric turbulence,” Opt. Eng. 33, 3254–3264 (1994).
    [CrossRef]
  19. B. J. Thelen, D. A. Carrara, R. G. Paxman, “Fine-resolution imagery of extended objects observed through volume turbulence using phase diverse speckle,” in Propagation and Imaging through the Atmosphere III, M. C. Roggemann, L. R. Bissonnette, eds., Proc. SPIE3763, 102–111 (1999).
    [CrossRef]
  20. V. I. Shmalhausen, N. A. Yaitskova, “Correction error in extended objects imaging through turbulent atmosphere,” Opt. Atmos. Ocean 9, 1462–1470 (1996).
  21. D. L. Fried, “Statistics of a geometric representation of wavefront distortion,” J. Opt. Soc. Am. 55, 1427–1435 (1965).
    [CrossRef]
  22. Quantitative estimation of the probability Ploc is an interesting problem; however, this estimation is beyond the scope of this paper.
  23. M. A. Vorontsov, “Parallel image processing based on an evolution equation with anisotropic gain: integrated opto-electronic architectures,” J. Opt. Soc. Am. A 16, 1623–1637 (1999).
    [CrossRef]
  24. G. W. Carhart, M. A. Vorontsov, “Synthetic imaging: non-adaptive anisoplanatic image correction in atmospheric turbulence,” Opt. Lett. 23, 745–747 (1998).
    [CrossRef]
  25. M. I. Charnotskii, V. A. Myakinin, V. U. Zavorotnyy, “Observation of superresolution in nonisoplanatic imaging through turbulence,” J. Opt. Soc. Am. A 7, 1345–1350 (1990).
    [CrossRef]
  26. M. A. Vorontsov, “Information processing with nonlinear optical two-dimensional feedback systems,” J. Eur. Opt. Soc. Quantum Semiclassic. Opt. B 1, 1–10 (1999).
    [CrossRef]

1999

1998

1997

1996

V. I. Shmalhausen, N. A. Yaitskova, “Correction error in extended objects imaging through turbulent atmosphere,” Opt. Atmos. Ocean 9, 1462–1470 (1996).

1994

M. C. Roggemann, C. A. Stoudt, B. M. Welsh, “Image spectrum signal-to-noise ratio improvement by statistical frame selection for adaptive optics imaging through atmospheric turbulence,” Opt. Eng. 33, 3254–3264 (1994).
[CrossRef]

R. G. Paxman, B. J. Thelen, J. H. Seldin, “Phase-diversity correction of space-variant turbulence-induced blur,” Opt. Lett. 19, 1231–1233 (1994).
[CrossRef] [PubMed]

1993

1991

1990

J. Primot, G. Rousset, J. C. Fortanella, “Deconvolution from wave-front sensing: a new technique for compensating turbulence-degraded images,” J. Opt. Soc. Am. A 7, 1589–1608 (1990).
[CrossRef]

M. I. Charnotskii, V. A. Myakinin, V. U. Zavorotnyy, “Observation of superresolution in nonisoplanatic imaging through turbulence,” J. Opt. Soc. Am. A 7, 1345–1350 (1990).
[CrossRef]

1988

1982

1978

1974

1970

A. Labeyrie, “Attainment of diffraction limited resolution in large telescopes by Fourier analyzing speckle patterns in star images,” Astron. Astrophys. 6, 85 (1970).

1965

Barclay, H. T.

Buffington, A.

Carhart, G. W.

Carrara, D. A.

B. J. Thelen, D. A. Carrara, R. G. Paxman, “Fine-resolution imagery of extended objects observed through volume turbulence using phase diverse speckle,” in Propagation and Imaging through the Atmosphere III, M. C. Roggemann, L. R. Bissonnette, eds., Proc. SPIE3763, 102–111 (1999).
[CrossRef]

Charnotskii, M. I.

Chernotskii, M. I.

Fienup, J. R.

Fortanella, J. C.

J. Primot, G. Rousset, J. C. Fortanella, “Deconvolution from wave-front sensing: a new technique for compensating turbulence-degraded images,” J. Opt. Soc. Am. A 7, 1589–1608 (1990).
[CrossRef]

Fraser, D.

D. Fraser, G. Thorpe, A. J. Lambert, “Atmospheric turbulence visualization with wide-area motion-blur restoration,” J. Opt. Soc. Am. A 16, 1751–1758 (1999).
[CrossRef]

D. Fraser, A. J. Lambert, “Wide area image restoration using a new iterative registration method,” in Image Reconstruction From Incomplete Data, M. A. Fiddy, R. P. Millane, eds., Proc. SPIE4123, 64–72 (2000).
[CrossRef]

Fried, D. L.

Fugate, R. Q.

R. Q. Fugate, “Laser beacon adaptive optics,” Opt. Photon. News, pp. 14–19 (June 1994).

Gardner, C. S.

Labeyrie, A.

A. Labeyrie, “Attainment of diffraction limited resolution in large telescopes by Fourier analyzing speckle patterns in star images,” Astron. Astrophys. 6, 85 (1970).

Lambert, A. J.

D. Fraser, G. Thorpe, A. J. Lambert, “Atmospheric turbulence visualization with wide-area motion-blur restoration,” J. Opt. Soc. Am. A 16, 1751–1758 (1999).
[CrossRef]

D. Fraser, A. J. Lambert, “Wide area image restoration using a new iterative registration method,” in Image Reconstruction From Incomplete Data, M. A. Fiddy, R. P. Millane, eds., Proc. SPIE4123, 64–72 (2000).
[CrossRef]

Muller, R. A.

Murphy, D. V.

Myakinin, V. A.

Paxman, R. G.

R. G. Paxman, B. J. Thelen, J. H. Seldin, “Phase-diversity correction of space-variant turbulence-induced blur,” Opt. Lett. 19, 1231–1233 (1994).
[CrossRef] [PubMed]

R. G. Paxman, J. R. Fienup, “Optical misalignment sensing and image reconstruction using phase diversity,” J. Opt. Soc. Am. A 5, 914–923 (1988).
[CrossRef]

B. J. Thelen, D. A. Carrara, R. G. Paxman, “Fine-resolution imagery of extended objects observed through volume turbulence using phase diverse speckle,” in Propagation and Imaging through the Atmosphere III, M. C. Roggemann, L. R. Bissonnette, eds., Proc. SPIE3763, 102–111 (1999).
[CrossRef]

Primmerman, C. A.

Primot, J.

J. Primot, G. Rousset, J. C. Fortanella, “Deconvolution from wave-front sensing: a new technique for compensating turbulence-degraded images,” J. Opt. Soc. Am. A 7, 1589–1608 (1990).
[CrossRef]

Pruidze, D. V.

Ricklin, J. C.

Roggemann, M. C.

M. C. Roggemann, C. A. Stoudt, B. M. Welsh, “Image spectrum signal-to-noise ratio improvement by statistical frame selection for adaptive optics imaging through atmospheric turbulence,” Opt. Eng. 33, 3254–3264 (1994).
[CrossRef]

M. C. Roggemann, B. M. Welsh, Imaging through Turbulence (CRC Press, Boca Raton, Fla., 1996).

Rousset, G.

J. Primot, G. Rousset, J. C. Fortanella, “Deconvolution from wave-front sensing: a new technique for compensating turbulence-degraded images,” J. Opt. Soc. Am. A 7, 1589–1608 (1990).
[CrossRef]

Seldin, J. H.

Shmalhausen, V. I.

V. I. Shmalhausen, N. A. Yaitskova, “Correction error in extended objects imaging through turbulent atmosphere,” Opt. Atmos. Ocean 9, 1462–1470 (1996).

Stoudt, C. A.

M. C. Roggemann, C. A. Stoudt, B. M. Welsh, “Image spectrum signal-to-noise ratio improvement by statistical frame selection for adaptive optics imaging through atmospheric turbulence,” Opt. Eng. 33, 3254–3264 (1994).
[CrossRef]

Thelen, B. J.

R. G. Paxman, B. J. Thelen, J. H. Seldin, “Phase-diversity correction of space-variant turbulence-induced blur,” Opt. Lett. 19, 1231–1233 (1994).
[CrossRef] [PubMed]

B. J. Thelen, D. A. Carrara, R. G. Paxman, “Fine-resolution imagery of extended objects observed through volume turbulence using phase diverse speckle,” in Propagation and Imaging through the Atmosphere III, M. C. Roggemann, L. R. Bissonnette, eds., Proc. SPIE3763, 102–111 (1999).
[CrossRef]

Thorpe, G.

Voelz, D. G.

Vorontsov, M. A.

Welsh, B. M.

M. C. Roggemann, C. A. Stoudt, B. M. Welsh, “Image spectrum signal-to-noise ratio improvement by statistical frame selection for adaptive optics imaging through atmospheric turbulence,” Opt. Eng. 33, 3254–3264 (1994).
[CrossRef]

B. M. Welsh, C. S. Gardner, “Effects of turbulence induced anisoplanatism on the imaging performance of adaptive astronomical telescopes using laser guide stars,” J. Opt. Soc. Am. A 8, 69–80 (1991).
[CrossRef]

M. C. Roggemann, B. M. Welsh, Imaging through Turbulence (CRC Press, Boca Raton, Fla., 1996).

Yaitskova, N. A.

V. I. Shmalhausen, N. A. Yaitskova, “Correction error in extended objects imaging through turbulent atmosphere,” Opt. Atmos. Ocean 9, 1462–1470 (1996).

Zavorotnyy, V. U.

Zollars, B. G.

Appl. Opt.

Astron. Astrophys.

A. Labeyrie, “Attainment of diffraction limited resolution in large telescopes by Fourier analyzing speckle patterns in star images,” Astron. Astrophys. 6, 85 (1970).

J. Eur. Opt. Soc. Quantum Semiclassic. Opt. B

M. A. Vorontsov, “Information processing with nonlinear optical two-dimensional feedback systems,” J. Eur. Opt. Soc. Quantum Semiclassic. Opt. B 1, 1–10 (1999).
[CrossRef]

J. Opt. Soc. Am.

J. Opt. Soc. Am. A

Opt. Atmos. Ocean

V. I. Shmalhausen, N. A. Yaitskova, “Correction error in extended objects imaging through turbulent atmosphere,” Opt. Atmos. Ocean 9, 1462–1470 (1996).

Opt. Eng.

M. C. Roggemann, C. A. Stoudt, B. M. Welsh, “Image spectrum signal-to-noise ratio improvement by statistical frame selection for adaptive optics imaging through atmospheric turbulence,” Opt. Eng. 33, 3254–3264 (1994).
[CrossRef]

Opt. Lett.

Opt. Photon. News

R. Q. Fugate, “Laser beacon adaptive optics,” Opt. Photon. News, pp. 14–19 (June 1994).

Other

M. C. Roggemann, B. M. Welsh, Imaging through Turbulence (CRC Press, Boca Raton, Fla., 1996).

P. L. Wizinowich, ed., Adaptive Optical Systems Technology, Proc. SPIE4007 (2000).

B. J. Thelen, D. A. Carrara, R. G. Paxman, “Fine-resolution imagery of extended objects observed through volume turbulence using phase diverse speckle,” in Propagation and Imaging through the Atmosphere III, M. C. Roggemann, L. R. Bissonnette, eds., Proc. SPIE3763, 102–111 (1999).
[CrossRef]

D. Fraser, A. J. Lambert, “Wide area image restoration using a new iterative registration method,” in Image Reconstruction From Incomplete Data, M. A. Fiddy, R. P. Millane, eds., Proc. SPIE4123, 64–72 (2000).
[CrossRef]

F. Roddier, ed., Adaptive Optics in Astronomy (Cambridge U. Press, Cambridge, UK, 1999), pp. 91–130.

Quantitative estimation of the probability Ploc is an interesting problem; however, this estimation is beyond the scope of this paper.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (11)

Fig. 1
Fig. 1

(a) White-light imaging system setup, (b) imaged scene geometry, (c) image in the absence of turbulence.

Fig. 2
Fig. 2

Short-exposure images of the reference object (a) without and (b) with the turbulence region (a single turbulent generator at the position z=0.64L). Point-source images used in the analysis are shown inside the dashed rectangular boxes in (a).

Fig. 3
Fig. 3

Mutual covariance coefficients for point-source images shown in Fig. 2a with turbulence layers created by using (a)–(c) a single and (d) two turbulence generators located at different distances l: (a) and (d), covariance coefficients for point-source image centroid motion in the x direction and (b) in the y direction; (c) covariance coefficient for point-source image widths. The spatial scale Δx/m corresponds to distances between point-source images in the object plane measured in centimeters.

Fig. 4
Fig. 4

(a) Normalized averaged point-source image width, (b) normalized standard deviation for point-source image centroid fluctuations, and (c) jitter parameter β, all versus normalized distance l: imaging system with single turbulence generator [curves 1 (solid curves)] and with two turbulence generators [curves 2 (dashed curves)].

Fig. 5
Fig. 5

Image quality metric temporal dynamics: (a) image quality fluctuations for sets of 1000 short-exposure images taken at a rate of 100 frames per second for different locations of turbulence generator 1 and (b) normalized image quality temporal correlation function BJ(iΔt) for Δt=10 ms and l=0.81. The image quality J is normalized by the image quality of the undistorted image, J0.

Fig. 6
Fig. 6

Influence of the turbulence layer location(s) on image quality metric: normalized image quality metric corresponding to the best Jb, (curve 1), frame-averaged Jav, (curve 2), and worst Jw, (curve 3) frames for (a) a single and (b) two turbulence generators at different locations, (c) normalized image quality metric standard deviation for a single (curve 1) and two (curve 2) turbulence generators.

Fig. 7
Fig. 7

Image quality variation within a set of 1000 frames taken at different turbulence generator location(s). The left column corresponds to the best and the right column to the worst frames: (a), (b) l=0.21 (single turbulence generator); (c), (d) l=0.47 (single turbulence generator); (e), (f) l=0.73 (two turbulence generators).

Fig. 8
Fig. 8

Processing of video data corresponding to different location(s) l of the turbulence generator(s) by using iterative procedure (8) (curves 2–5) and the image quality frame-to-frame evolution curve for two turbulence generators (curve 1). Each set of images used in the calculations of curves 2–5 is independent.

Fig. 9
Fig. 9

Synthetic image quality metric Js corresponding to n=1000 for different turbulence generator locations normalized by (a) averaged image quality metric values Jn and (b) the quality metric of the undistorted image, J0: synthetic image quality metrics curves 1 and 2 (solid curves) and curves 3 and 4 (dashed curves) averaged metrics, corresponding to a single turbulence generator (curves 1 and 3) and to two turbulence generators (curves 2 and 4). The dashed horizontal line corresponds to the quality metric J0 for the undistorted image.

Fig. 10
Fig. 10

Long-exposure (left column) and synthetic (right column) images corresponding to conditions indicated by points A, B, and C in Fig. 9a: (a), (b) l=0.73 (single turbulence generator), (c), (d) l=0.91 (two turbulence generators), (e), (f) l=0.21 (single turbulence generator).

Fig. 11
Fig. 11

Image enhancement obtained by using the synthetic imaging technique. Examples of (a) undistorted and (b) synthetic images for l=0.73 and a single turbulence generator are given. Synthetic image (b) was obtained by using undistorted image (a) as an initial condition in iterative procedure (8).

Equations (16)

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

xj=Ej-1ΩjxIj(r)d2r,yj=Ej-1ΩjyIj(r)d2r,
(wjx)2=Ej-1Ωj(x-xj)2Ij(r)d2r,
(wjy)2=Ej-1Ωj(y-yj)2Ij(r)d2r,
Ej=ΩjIj(r)d2r,
Bijδx=δxjδxi/(σjδxσiδx),Bijδy=δyjδyi/(σjδyσiδy),
Bijδr=δrjδri/(σjδrσiδr),Bijw=wjwi/(σjwσiw),
-2ik A(r, z)z=2A(r, z),
J= [Id(r)-I0]2 d2r.
J(r)= [Id(r)-I0]2G(r-r, a)d2r
 [2I(r)]2G(r-r, a)d2r,
τ Is(r, t)t=-Kδ(r, t)[Is(r, t)-I(r, tn)],
tnt<tn+1,
δ(r, t)=J(r, tn)-Js(r, t)forJ(r, tn)>J(r, t)0otherwise.
In+1s(r)=Ins(r)-Kδn(r)[Ins(r)-In(r)],
δn(r)=Jn(r)-Jns(r)forJn(r)>Jns(r),
δn(r)=0otherwise.

Metrics