Abstract

An instrument has been built for the study of the atmospheric turbulence by measuring the fluctuation of the angle of arrival across a telescope aperture using moiré deflectometry. A slightly divergent laser beam passes through a turbulent ground level atmosphere and enters the telescope aperture. The laser beam is recollimated behind the telescope’s focal point by means of a collimator. The collimated beam passes through a moiré deflectometer. The fluctuating self-image of the first grating is formed on the second grating of the moiré deflectometer and fluctuating moiré fringes are formed. Using moiré fringe fluctuations we have calculated the fluctuations of the angle of arrival, the Fried’s parameter r0, and the atmospheric refractive index structure constant. Because of the magnifications of the telescope and moiré deflectometry, the precision of the technique can potentially be 1 order of magnitude more precise than previous methods.

© 2010 Optical Society of America

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References

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  1. S. Rasouli and M. T. Tavassoly, Opt. Lett. 31, 3276 (2006).
    [CrossRef] [PubMed]
  2. S. Rasouli and M. T. Tavassoly, Opt. Lett. 33, 980 (2008).
    [CrossRef] [PubMed]
  3. S. Rasouli and M. T. Tavassoly, Proc. SPIE 6364, 63640G (2006).
    [CrossRef]
  4. S. Rasouli, K. Madanipour, and M. T. Tavassoly, Proc. SPIE 6364, 63640K (2006).
    [CrossRef]
  5. S. Rasouli, A. N. Ramaprakash, H. K. Das, C. V. Rajarshi, Y. Rajabi, and M. Dashti, Proc. SPIE 7476, 74760K (2009).
    [CrossRef]
  6. F. Roddier, in Progress in Optics XIX, E.Wolf, ed. (North-Holland, 1981), pp. 281–376.
    [CrossRef]
  7. M. Sarazin and F. Roddier, Astron. Astrophys. 227, 294 (1990).
  8. M. S. Belen’kii, J. M. Stewart, and P. Gillespie, Appl. Opt. 40, 1321 (2001).
    [CrossRef]

2009 (1)

S. Rasouli, A. N. Ramaprakash, H. K. Das, C. V. Rajarshi, Y. Rajabi, and M. Dashti, Proc. SPIE 7476, 74760K (2009).
[CrossRef]

2008 (1)

2006 (3)

S. Rasouli and M. T. Tavassoly, Proc. SPIE 6364, 63640G (2006).
[CrossRef]

S. Rasouli, K. Madanipour, and M. T. Tavassoly, Proc. SPIE 6364, 63640K (2006).
[CrossRef]

S. Rasouli and M. T. Tavassoly, Opt. Lett. 31, 3276 (2006).
[CrossRef] [PubMed]

2001 (1)

1990 (1)

M. Sarazin and F. Roddier, Astron. Astrophys. 227, 294 (1990).

Belen’kii, M. S.

Das, H. K.

S. Rasouli, A. N. Ramaprakash, H. K. Das, C. V. Rajarshi, Y. Rajabi, and M. Dashti, Proc. SPIE 7476, 74760K (2009).
[CrossRef]

Dashti, M.

S. Rasouli, A. N. Ramaprakash, H. K. Das, C. V. Rajarshi, Y. Rajabi, and M. Dashti, Proc. SPIE 7476, 74760K (2009).
[CrossRef]

Gillespie, P.

Madanipour, K.

S. Rasouli, K. Madanipour, and M. T. Tavassoly, Proc. SPIE 6364, 63640K (2006).
[CrossRef]

Rajabi, Y.

S. Rasouli, A. N. Ramaprakash, H. K. Das, C. V. Rajarshi, Y. Rajabi, and M. Dashti, Proc. SPIE 7476, 74760K (2009).
[CrossRef]

Rajarshi, C. V.

S. Rasouli, A. N. Ramaprakash, H. K. Das, C. V. Rajarshi, Y. Rajabi, and M. Dashti, Proc. SPIE 7476, 74760K (2009).
[CrossRef]

Ramaprakash, A. N.

S. Rasouli, A. N. Ramaprakash, H. K. Das, C. V. Rajarshi, Y. Rajabi, and M. Dashti, Proc. SPIE 7476, 74760K (2009).
[CrossRef]

Rasouli, S.

S. Rasouli, A. N. Ramaprakash, H. K. Das, C. V. Rajarshi, Y. Rajabi, and M. Dashti, Proc. SPIE 7476, 74760K (2009).
[CrossRef]

S. Rasouli and M. T. Tavassoly, Opt. Lett. 33, 980 (2008).
[CrossRef] [PubMed]

S. Rasouli, K. Madanipour, and M. T. Tavassoly, Proc. SPIE 6364, 63640K (2006).
[CrossRef]

S. Rasouli and M. T. Tavassoly, Proc. SPIE 6364, 63640G (2006).
[CrossRef]

S. Rasouli and M. T. Tavassoly, Opt. Lett. 31, 3276 (2006).
[CrossRef] [PubMed]

Roddier, F.

M. Sarazin and F. Roddier, Astron. Astrophys. 227, 294 (1990).

F. Roddier, in Progress in Optics XIX, E.Wolf, ed. (North-Holland, 1981), pp. 281–376.
[CrossRef]

Sarazin, M.

M. Sarazin and F. Roddier, Astron. Astrophys. 227, 294 (1990).

Stewart, J. M.

Tavassoly, M. T.

S. Rasouli and M. T. Tavassoly, Opt. Lett. 33, 980 (2008).
[CrossRef] [PubMed]

S. Rasouli and M. T. Tavassoly, Opt. Lett. 31, 3276 (2006).
[CrossRef] [PubMed]

S. Rasouli and M. T. Tavassoly, Proc. SPIE 6364, 63640G (2006).
[CrossRef]

S. Rasouli, K. Madanipour, and M. T. Tavassoly, Proc. SPIE 6364, 63640K (2006).
[CrossRef]

Appl. Opt. (1)

Astron. Astrophys. (1)

M. Sarazin and F. Roddier, Astron. Astrophys. 227, 294 (1990).

Opt. Lett. (2)

Proc. SPIE (3)

S. Rasouli and M. T. Tavassoly, Proc. SPIE 6364, 63640G (2006).
[CrossRef]

S. Rasouli, K. Madanipour, and M. T. Tavassoly, Proc. SPIE 6364, 63640K (2006).
[CrossRef]

S. Rasouli, A. N. Ramaprakash, H. K. Das, C. V. Rajarshi, Y. Rajabi, and M. Dashti, Proc. SPIE 7476, 74760K (2009).
[CrossRef]

Other (1)

F. Roddier, in Progress in Optics XIX, E.Wolf, ed. (North-Holland, 1981), pp. 281–376.
[CrossRef]

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Figures (3)

Fig. 1
Fig. 1

Schematic diagram of the experimental setup: CL , F, G 1 , G 2 , and PL stand for the collimating lens, bandpass filter, first grating, second grating, and the lens that projects the moiré pattern produced on the diffuser D on the CCD, respectively.

Fig. 2
Fig. 2

(a) Typical moiré pattern and (b) the corresponding low frequency illumination distribution.

Fig. 3
Fig. 3

Typical vertical components of AA fluctuations at five different points on the telescope aperture versus time; all of the plots correspond to a given vertical trace.

Equations (9)

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

α = α γ ,
s = d m d l .
α = l Z k = 1 Z k d d m s .
α = γ α = f f 1 Z k d d m s .
B α ( ξ , η ) = α ( x , y ) α ( x + ξ , y + η ) ,
B α ( ξ , η ) = 0.145 λ 2 r 0 ( 5 / 3 ) [ ( ξ 2 + η 2 ) ( 1 / 6 ) 1 3 ξ 2 ( ξ 2 + η 2 ) ( 7 / 6 ) ] ,
B α ( ξ , 0 ) = B l ( ξ ) = 0.097 ( λ r 0 ) 5 / 3 ( λ ξ ) 1 / 3 .
B α ( 0 , η ) = B t ( η ) = 0.145 ( λ r 0 ) 5 / 3 ( λ η ) 1 / 3 .
C n 2 = 0.06 L 1 λ 2 r 0 5 / 3 ,

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