Abstract

This paper investigates active and passive short-wave infrared (SWIR) imaging for slant paths close to ground. The main sensor, a gated SWIR camera, was collecting both passive and active images along a 2 km long path over an airfield and also from our rooftop laboratory looking over open fields. For some investigations we also used a gated system working in the near-infrared region and thermal as well as color CCD cameras. The sensor was elevated by a lift in steps from 1.6–13.5 m or placed in a rooftop laboratory 13 m above ground. Targets were resolution charts and man targets. The turbulence was measured along the path with anemometers and scintillometers. The image performance was evaluated by measurement of the image blur and also by performing observer perception tests. The results reveal a strong dependence on the sensor height especially during daytime.

© 2013 Optical Society of America

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    [CrossRef]

2012 (3)

B. Göhler and P. Lutzmann, “Range accuracy of a gated-viewing system as a function of the number of averaged images,” Proc. SPIE 8542, 854205 (2012).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path range gated imaging of static and moving targets,” Proc. SPIE 8379, 83790W (2012).
[CrossRef]

O. Steinvall, M. Elmqvist, and T. Chevalier, “Identification of handheld objects and human activities in active and passive imaging,” Proc. SPIE 8542, 854206 (2012).
[CrossRef]

2011 (3)

L. Sjöqvist, L. Allard, O. Gustafsson, M. Henriksson, and M. Pettersson, “Turbulence effects in a horizontal propagation path close to ground: implications for optics detection,” Proc. SPIE 8187, 81870M (2011).
[CrossRef]

M. Henriksson and L. Sjöqvist, “Time-correlated single-photon counting laser radar in turbulence,” Proc. SPIE 8187, 81870N (2011).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path 1.5 μm range gated imaging close to ground,” Proc. SPIE 8037, 803703 (2011).
[CrossRef]

2010 (2)

O. Steinvall, M. Elmqvist, K. Karlsson, H. Larsson, and M. Axelsson, “Laser imaging of small surface vessels and people at sea,” Proc. SPIE 7684, 768417 (2010).

B. Göhler and P. Lutzmann, “Range accuracy of a gated-viewing system compared to a 3-D Flash LADA Runder different turbulence conditions,” Proc. SPIE 7835, 783504 (2010).
[CrossRef]

2009 (3)

K. O. S. Gustafsson, M. Henriksson, and L. Sjöqvist, “Wall induced turbulence distortions of optical measurements,” Proc. SPIE 74820, 74820E (2009).
[CrossRef]

O. David, R. Schneider, and R. Israeli, “Advance in active night vision for filling the gap in remote sensing,” Proc. SPIE 7482, 748203 (2009).

E. Repasi, P. Lutzmann, O. Steinvall, M. Elmqvist, B. Göhler, and G. Anstett, “Advanced short-wavelength infrared range-gated imaging for ground applications in monostatic and bistatic configurations,” Appl. Opt. 48, 5956–5969 (2009).
[CrossRef]

2007 (2)

R. L. Espinola, E. L. Jacobs, C. E. Halford, R. Vollmerhausen, and D. H. Tofsted, “Modeling the target acquisition performance of active imaging systems,” Opt. Express 15, 3816–3832 (2007).
[CrossRef]

C. E. Halford, A. L. Robinson, R. G. Driggers, and E. L. Jacobs, “Tilted surfaces in SWIR imagery: speckle simulation and a simple contrast model,” Opt. Eng. 46, 053201 (2007).
[CrossRef]

2006 (2)

O. Steinvall, P. Andersson, and M. Elmqvist, “Image quality for range-gated systems during different ranges atmospheric conditions,” Proc. SPIE 6396, 639607 (2006).
[CrossRef]

D. Bonnier, S. Lelievre, and L. Demers, “On the safe use of long-range laser active imager in the near-infrared for Homeland Security,” Proc. SPIE 6206, 62060A (2006).

2005 (1)

E. Jacobs and R. L. Espinola, “Beam scintillation effects on identification performance with active imaging systems,” Proc. SPIE 5987, 598703 (2005).

2004 (2)

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

D. H. Tofsted and S. G. O’Brien, “Simulation of atmospheric turbulence image distortion and scintillation effects impacting short wave infrared (SWIR) active imaging systems,” Proc. SPIE 5431, 160–171 (2004).

2003 (3)

C. J. Carrano, “Progress in horizontal and slant-path imaging using speckle imaging,” Proc. SPIE 5001, 56–64 (2003).
[CrossRef]

D. H. Tofsted, “Analytic improvements to the atmospheric turbulence optical transfer function,” Proc. SPIE 5075, 281–292 (2003).

R. G. Driggers, R. H. Vollmerhausen, N. Devitt, C. Halford, and K. J. Barnard, “Impact of speckle on laser range-gated shortwave infrared imaging system target identification performance,” Opt. Eng. 42, 738–746 (2003).
[CrossRef]

2002 (2)

D. Edouart, P. Churouxa, and P. H. Flamant, “Burst illumination imaging lidar: intensity correlation function in the image plane,” Proc. SPIE 4723, 189–197 (2002).

O. Korotkova and L. C. Andrews, “Speckle propagation through atmospheric turbulence: effects of partial coherence of the target,” Proc. SPIE 4723, 73–84 (2002).
[CrossRef]

2001 (1)

D. Dayton, S. Browne, J. Gonglewski, S. Sandven, J. Gallegos, and M. Shilko, “Long-range laser illuminated imaging: analysis and experimental demonstrations,” Opt. Eng. 40, 1001–1009 (2001).
[CrossRef]

1998 (1)

J. D. O’Connor, B. L. O’Kane, C. K. Royal, K. L. Ayscue, D. E. Bonzo, and B. M. Nystrom, “Recognition of human activities using handheld thermal systems,” Proc. SPIE 3394, 51–61 (1998).
[CrossRef]

1978 (1)

R. J. Hill, “Spectra of fluctuation in refractivity temperature, humidity, and the temperature-humidity cospectrum in the inertial and dissipation ranges,” Radio Sci. 13, 953–961 (1978).
[CrossRef]

1975 (1)

R. L. Fante, “Electromagnetic beam propagation in turbulent media,” Proc. IEEE 63, 1669–1692 (1975).

1965 (1)

J. W. Goodman, “Some effects of target-induced scintillation on optical radar performance,” Proc. IEEE 53, 1688–1700 (1965).
[CrossRef]

Aflalo, T.

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

Allard, L.

L. Sjöqvist, L. Allard, O. Gustafsson, M. Henriksson, and M. Pettersson, “Turbulence effects in a horizontal propagation path close to ground: implications for optics detection,” Proc. SPIE 8187, 81870M (2011).
[CrossRef]

Andersson, P.

O. Steinvall, P. Andersson, and M. Elmqvist, “Image quality for range-gated systems during different ranges atmospheric conditions,” Proc. SPIE 6396, 639607 (2006).
[CrossRef]

Andrews, L. C.

O. Korotkova and L. C. Andrews, “Speckle propagation through atmospheric turbulence: effects of partial coherence of the target,” Proc. SPIE 4723, 73–84 (2002).
[CrossRef]

L. C. Andrews and R. L. Phillips, Laser Beam Propagation through Random Media (SPIE, Optical Engineering, 1998).

L. C. Andrews, R. L. Phillips, and C. Y. Hopen, Laser Beam Scintillation with Applications (SPIE Optical Engineering, 2001).

Anstett, G.

Axelsson, M.

O. Steinvall, M. Elmqvist, K. Karlsson, H. Larsson, and M. Axelsson, “Laser imaging of small surface vessels and people at sea,” Proc. SPIE 7684, 768417 (2010).

Ayscue, K. L.

J. D. O’Connor, B. L. O’Kane, C. K. Royal, K. L. Ayscue, D. E. Bonzo, and B. M. Nystrom, “Recognition of human activities using handheld thermal systems,” Proc. SPIE 3394, 51–61 (1998).
[CrossRef]

Banakh, V. A.

V. A. Banakh and V. L. Mironov, LIDAR in a Turbulent Atmosphere (Artech House, 1987).

Barnard, K. J.

R. G. Driggers, R. H. Vollmerhausen, N. Devitt, C. Halford, and K. J. Barnard, “Impact of speckle on laser range-gated shortwave infrared imaging system target identification performance,” Opt. Eng. 42, 738–746 (2003).
[CrossRef]

Beland, R. R.

R. R. Beland, “Propagation through atmospheric optical turbulence” in The Infrared and Electro-Optical Systems Handbook, J. S. Accetta and D. L. Shumaker, eds., Vol. 2 (SPIE, 1993).

Bonnier, D.

D. Bonnier, S. Lelievre, and L. Demers, “On the safe use of long-range laser active imager in the near-infrared for Homeland Security,” Proc. SPIE 6206, 62060A (2006).

Bonzo, D. E.

J. D. O’Connor, B. L. O’Kane, C. K. Royal, K. L. Ayscue, D. E. Bonzo, and B. M. Nystrom, “Recognition of human activities using handheld thermal systems,” Proc. SPIE 3394, 51–61 (1998).
[CrossRef]

Browne, S.

D. Dayton, S. Browne, J. Gonglewski, S. Sandven, J. Gallegos, and M. Shilko, “Long-range laser illuminated imaging: analysis and experimental demonstrations,” Opt. Eng. 40, 1001–1009 (2001).
[CrossRef]

Cardani, J. C.

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

Carrano, C. J.

C. J. Carrano, “Progress in horizontal and slant-path imaging using speckle imaging,” Proc. SPIE 5001, 56–64 (2003).
[CrossRef]

Chevalier, T.

O. Steinvall, M. Elmqvist, and T. Chevalier, “Identification of handheld objects and human activities in active and passive imaging,” Proc. SPIE 8542, 854206 (2012).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path range gated imaging of static and moving targets,” Proc. SPIE 8379, 83790W (2012).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path 1.5 μm range gated imaging close to ground,” Proc. SPIE 8037, 803703 (2011).
[CrossRef]

Churouxa, P.

D. Edouart, P. Churouxa, and P. H. Flamant, “Burst illumination imaging lidar: intensity correlation function in the image plane,” Proc. SPIE 4723, 189–197 (2002).

David, O.

O. David, R. Schneider, and R. Israeli, “Advance in active night vision for filling the gap in remote sensing,” Proc. SPIE 7482, 748203 (2009).

Davidson, K.

G. Potvin, D. Dion, J. L. Forand, C. Zeisse, P. Frederickson, and K. Davidson, “Scintillation in the coastal atmospheric surface layer,” in 14th Symposium on Boundary Layer and Turbulence (American Meteorological Society, 2000), pp. 534–537.

Dayton, D.

D. Dayton, S. Browne, J. Gonglewski, S. Sandven, J. Gallegos, and M. Shilko, “Long-range laser illuminated imaging: analysis and experimental demonstrations,” Opt. Eng. 40, 1001–1009 (2001).
[CrossRef]

Dayton, D. C.

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

Demers, L.

D. Bonnier, S. Lelievre, and L. Demers, “On the safe use of long-range laser active imager in the near-infrared for Homeland Security,” Proc. SPIE 6206, 62060A (2006).

Devitt, N.

R. G. Driggers, R. H. Vollmerhausen, N. Devitt, C. Halford, and K. J. Barnard, “Impact of speckle on laser range-gated shortwave infrared imaging system target identification performance,” Opt. Eng. 42, 738–746 (2003).
[CrossRef]

Dion, D.

G. Potvin, D. Dion, J. L. Forand, C. Zeisse, P. Frederickson, and K. Davidson, “Scintillation in the coastal atmospheric surface layer,” in 14th Symposium on Boundary Layer and Turbulence (American Meteorological Society, 2000), pp. 534–537.

Driggers, R. G.

C. E. Halford, A. L. Robinson, R. G. Driggers, and E. L. Jacobs, “Tilted surfaces in SWIR imagery: speckle simulation and a simple contrast model,” Opt. Eng. 46, 053201 (2007).
[CrossRef]

R. G. Driggers, R. H. Vollmerhausen, N. Devitt, C. Halford, and K. J. Barnard, “Impact of speckle on laser range-gated shortwave infrared imaging system target identification performance,” Opt. Eng. 42, 738–746 (2003).
[CrossRef]

Edouart, D.

D. Edouart, P. Churouxa, and P. H. Flamant, “Burst illumination imaging lidar: intensity correlation function in the image plane,” Proc. SPIE 4723, 189–197 (2002).

Elmqvist, M.

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path range gated imaging of static and moving targets,” Proc. SPIE 8379, 83790W (2012).
[CrossRef]

O. Steinvall, M. Elmqvist, and T. Chevalier, “Identification of handheld objects and human activities in active and passive imaging,” Proc. SPIE 8542, 854206 (2012).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path 1.5 μm range gated imaging close to ground,” Proc. SPIE 8037, 803703 (2011).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, H. Larsson, and M. Axelsson, “Laser imaging of small surface vessels and people at sea,” Proc. SPIE 7684, 768417 (2010).

E. Repasi, P. Lutzmann, O. Steinvall, M. Elmqvist, B. Göhler, and G. Anstett, “Advanced short-wavelength infrared range-gated imaging for ground applications in monostatic and bistatic configurations,” Appl. Opt. 48, 5956–5969 (2009).
[CrossRef]

O. Steinvall, P. Andersson, and M. Elmqvist, “Image quality for range-gated systems during different ranges atmospheric conditions,” Proc. SPIE 6396, 639607 (2006).
[CrossRef]

Espinola, R. L.

R. L. Espinola, E. L. Jacobs, C. E. Halford, R. Vollmerhausen, and D. H. Tofsted, “Modeling the target acquisition performance of active imaging systems,” Opt. Express 15, 3816–3832 (2007).
[CrossRef]

E. Jacobs and R. L. Espinola, “Beam scintillation effects on identification performance with active imaging systems,” Proc. SPIE 5987, 598703 (2005).

Fante, R. L.

R. L. Fante, “Electromagnetic beam propagation in turbulent media,” Proc. IEEE 63, 1669–1692 (1975).

Flamant, P. H.

D. Edouart, P. Churouxa, and P. H. Flamant, “Burst illumination imaging lidar: intensity correlation function in the image plane,” Proc. SPIE 4723, 189–197 (2002).

Forand, J. L.

G. Potvin, D. Dion, J. L. Forand, C. Zeisse, P. Frederickson, and K. Davidson, “Scintillation in the coastal atmospheric surface layer,” in 14th Symposium on Boundary Layer and Turbulence (American Meteorological Society, 2000), pp. 534–537.

Frederickson, P.

G. Potvin, D. Dion, J. L. Forand, C. Zeisse, P. Frederickson, and K. Davidson, “Scintillation in the coastal atmospheric surface layer,” in 14th Symposium on Boundary Layer and Turbulence (American Meteorological Society, 2000), pp. 534–537.

Gallegos, J.

D. Dayton, S. Browne, J. Gonglewski, S. Sandven, J. Gallegos, and M. Shilko, “Long-range laser illuminated imaging: analysis and experimental demonstrations,” Opt. Eng. 40, 1001–1009 (2001).
[CrossRef]

Göhler, B.

B. Göhler and P. Lutzmann, “Range accuracy of a gated-viewing system as a function of the number of averaged images,” Proc. SPIE 8542, 854205 (2012).
[CrossRef]

B. Göhler and P. Lutzmann, “Range accuracy of a gated-viewing system compared to a 3-D Flash LADA Runder different turbulence conditions,” Proc. SPIE 7835, 783504 (2010).
[CrossRef]

E. Repasi, P. Lutzmann, O. Steinvall, M. Elmqvist, B. Göhler, and G. Anstett, “Advanced short-wavelength infrared range-gated imaging for ground applications in monostatic and bistatic configurations,” Appl. Opt. 48, 5956–5969 (2009).
[CrossRef]

B. Göhler and P. Lutzmann, “An analytical performance model for active imaging systems including slant-path applications,” 4th International Symposium on Optronics in Defence and Security, CD-ROM, Paris, France, 3–5 February2010.

Gonglewski, J.

D. Dayton, S. Browne, J. Gonglewski, S. Sandven, J. Gallegos, and M. Shilko, “Long-range laser illuminated imaging: analysis and experimental demonstrations,” Opt. Eng. 40, 1001–1009 (2001).
[CrossRef]

Gonglewski, J. D.

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

Goodman, J. W.

J. W. Goodman, “Some effects of target-induced scintillation on optical radar performance,” Proc. IEEE 53, 1688–1700 (1965).
[CrossRef]

Gustafsson, K. O. S.

K. O. S. Gustafsson, M. Henriksson, and L. Sjöqvist, “Wall induced turbulence distortions of optical measurements,” Proc. SPIE 74820, 74820E (2009).
[CrossRef]

Gustafsson, O.

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path range gated imaging of static and moving targets,” Proc. SPIE 8379, 83790W (2012).
[CrossRef]

L. Sjöqvist, L. Allard, O. Gustafsson, M. Henriksson, and M. Pettersson, “Turbulence effects in a horizontal propagation path close to ground: implications for optics detection,” Proc. SPIE 8187, 81870M (2011).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path 1.5 μm range gated imaging close to ground,” Proc. SPIE 8037, 803703 (2011).
[CrossRef]

Halford, C.

R. G. Driggers, R. H. Vollmerhausen, N. Devitt, C. Halford, and K. J. Barnard, “Impact of speckle on laser range-gated shortwave infrared imaging system target identification performance,” Opt. Eng. 42, 738–746 (2003).
[CrossRef]

Halford, C. E.

C. E. Halford, A. L. Robinson, R. G. Driggers, and E. L. Jacobs, “Tilted surfaces in SWIR imagery: speckle simulation and a simple contrast model,” Opt. Eng. 46, 053201 (2007).
[CrossRef]

R. L. Espinola, E. L. Jacobs, C. E. Halford, R. Vollmerhausen, and D. H. Tofsted, “Modeling the target acquisition performance of active imaging systems,” Opt. Express 15, 3816–3832 (2007).
[CrossRef]

Henriksson, M.

L. Sjöqvist, L. Allard, O. Gustafsson, M. Henriksson, and M. Pettersson, “Turbulence effects in a horizontal propagation path close to ground: implications for optics detection,” Proc. SPIE 8187, 81870M (2011).
[CrossRef]

M. Henriksson and L. Sjöqvist, “Time-correlated single-photon counting laser radar in turbulence,” Proc. SPIE 8187, 81870N (2011).
[CrossRef]

K. O. S. Gustafsson, M. Henriksson, and L. Sjöqvist, “Wall induced turbulence distortions of optical measurements,” Proc. SPIE 74820, 74820E (2009).
[CrossRef]

Hill, R. J.

R. J. Hill, “Spectra of fluctuation in refractivity temperature, humidity, and the temperature-humidity cospectrum in the inertial and dissipation ranges,” Radio Sci. 13, 953–961 (1978).
[CrossRef]

Hopen, C. Y.

L. C. Andrews, R. L. Phillips, and C. Y. Hopen, Laser Beam Scintillation with Applications (SPIE Optical Engineering, 2001).

Israeli, R.

O. David, R. Schneider, and R. Israeli, “Advance in active night vision for filling the gap in remote sensing,” Proc. SPIE 7482, 748203 (2009).

Jacobs, E.

E. Jacobs and R. L. Espinola, “Beam scintillation effects on identification performance with active imaging systems,” Proc. SPIE 5987, 598703 (2005).

Jacobs, E. L.

R. L. Espinola, E. L. Jacobs, C. E. Halford, R. Vollmerhausen, and D. H. Tofsted, “Modeling the target acquisition performance of active imaging systems,” Opt. Express 15, 3816–3832 (2007).
[CrossRef]

C. E. Halford, A. L. Robinson, R. G. Driggers, and E. L. Jacobs, “Tilted surfaces in SWIR imagery: speckle simulation and a simple contrast model,” Opt. Eng. 46, 053201 (2007).
[CrossRef]

Karlsson, K.

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path range gated imaging of static and moving targets,” Proc. SPIE 8379, 83790W (2012).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path 1.5 μm range gated imaging close to ground,” Proc. SPIE 8037, 803703 (2011).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, H. Larsson, and M. Axelsson, “Laser imaging of small surface vessels and people at sea,” Proc. SPIE 7684, 768417 (2010).

Kopeika, N. S.

N. S. Kopeika, A System Engineering Approach to Imaging (SPIE, 1998).

Korotkova, O.

O. Korotkova and L. C. Andrews, “Speckle propagation through atmospheric turbulence: effects of partial coherence of the target,” Proc. SPIE 4723, 73–84 (2002).
[CrossRef]

Kovacs, M. A.

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

Larsson, H.

O. Steinvall, M. Elmqvist, K. Karlsson, H. Larsson, and M. Axelsson, “Laser imaging of small surface vessels and people at sea,” Proc. SPIE 7684, 768417 (2010).

Lelievre, S.

D. Bonnier, S. Lelievre, and L. Demers, “On the safe use of long-range laser active imager in the near-infrared for Homeland Security,” Proc. SPIE 6206, 62060A (2006).

Lutzmann, P.

B. Göhler and P. Lutzmann, “Range accuracy of a gated-viewing system as a function of the number of averaged images,” Proc. SPIE 8542, 854205 (2012).
[CrossRef]

B. Göhler and P. Lutzmann, “Range accuracy of a gated-viewing system compared to a 3-D Flash LADA Runder different turbulence conditions,” Proc. SPIE 7835, 783504 (2010).
[CrossRef]

E. Repasi, P. Lutzmann, O. Steinvall, M. Elmqvist, B. Göhler, and G. Anstett, “Advanced short-wavelength infrared range-gated imaging for ground applications in monostatic and bistatic configurations,” Appl. Opt. 48, 5956–5969 (2009).
[CrossRef]

B. Göhler and P. Lutzmann, “An analytical performance model for active imaging systems including slant-path applications,” 4th International Symposium on Optronics in Defence and Security, CD-ROM, Paris, France, 3–5 February2010.

Maia, F.

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

Martin, J. B.

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

Mironov, V. L.

V. A. Banakh and V. L. Mironov, LIDAR in a Turbulent Atmosphere (Artech House, 1987).

Nystrom, B. M.

J. D. O’Connor, B. L. O’Kane, C. K. Royal, K. L. Ayscue, D. E. Bonzo, and B. M. Nystrom, “Recognition of human activities using handheld thermal systems,” Proc. SPIE 3394, 51–61 (1998).
[CrossRef]

O’Brien, S. G.

D. H. Tofsted and S. G. O’Brien, “Simulation of atmospheric turbulence image distortion and scintillation effects impacting short wave infrared (SWIR) active imaging systems,” Proc. SPIE 5431, 160–171 (2004).

O’Connor, J. D.

J. D. O’Connor, B. L. O’Kane, C. K. Royal, K. L. Ayscue, D. E. Bonzo, and B. M. Nystrom, “Recognition of human activities using handheld thermal systems,” Proc. SPIE 3394, 51–61 (1998).
[CrossRef]

O’Kane, B. L.

J. D. O’Connor, B. L. O’Kane, C. K. Royal, K. L. Ayscue, D. E. Bonzo, and B. M. Nystrom, “Recognition of human activities using handheld thermal systems,” Proc. SPIE 3394, 51–61 (1998).
[CrossRef]

Pettersson, M.

L. Sjöqvist, L. Allard, O. Gustafsson, M. Henriksson, and M. Pettersson, “Turbulence effects in a horizontal propagation path close to ground: implications for optics detection,” Proc. SPIE 8187, 81870M (2011).
[CrossRef]

Phillips, R. L.

L. C. Andrews, R. L. Phillips, and C. Y. Hopen, Laser Beam Scintillation with Applications (SPIE Optical Engineering, 2001).

L. C. Andrews and R. L. Phillips, Laser Beam Propagation through Random Media (SPIE, Optical Engineering, 1998).

Potvin, G.

G. Potvin, D. Dion, J. L. Forand, C. Zeisse, P. Frederickson, and K. Davidson, “Scintillation in the coastal atmospheric surface layer,” in 14th Symposium on Boundary Layer and Turbulence (American Meteorological Society, 2000), pp. 534–537.

Repasi, E.

Robinson, A. L.

C. E. Halford, A. L. Robinson, R. G. Driggers, and E. L. Jacobs, “Tilted surfaces in SWIR imagery: speckle simulation and a simple contrast model,” Opt. Eng. 46, 053201 (2007).
[CrossRef]

Roggemann, M. C.

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

Royal, C. K.

J. D. O’Connor, B. L. O’Kane, C. K. Royal, K. L. Ayscue, D. E. Bonzo, and B. M. Nystrom, “Recognition of human activities using handheld thermal systems,” Proc. SPIE 3394, 51–61 (1998).
[CrossRef]

Sandven, S.

D. Dayton, S. Browne, J. Gonglewski, S. Sandven, J. Gallegos, and M. Shilko, “Long-range laser illuminated imaging: analysis and experimental demonstrations,” Opt. Eng. 40, 1001–1009 (2001).
[CrossRef]

Schneider, R.

O. David, R. Schneider, and R. Israeli, “Advance in active night vision for filling the gap in remote sensing,” Proc. SPIE 7482, 748203 (2009).

Shilko, M.

D. Dayton, S. Browne, J. Gonglewski, S. Sandven, J. Gallegos, and M. Shilko, “Long-range laser illuminated imaging: analysis and experimental demonstrations,” Opt. Eng. 40, 1001–1009 (2001).
[CrossRef]

Shilko, M. L.

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

Sjöqvist, L.

L. Sjöqvist, L. Allard, O. Gustafsson, M. Henriksson, and M. Pettersson, “Turbulence effects in a horizontal propagation path close to ground: implications for optics detection,” Proc. SPIE 8187, 81870M (2011).
[CrossRef]

M. Henriksson and L. Sjöqvist, “Time-correlated single-photon counting laser radar in turbulence,” Proc. SPIE 8187, 81870N (2011).
[CrossRef]

K. O. S. Gustafsson, M. Henriksson, and L. Sjöqvist, “Wall induced turbulence distortions of optical measurements,” Proc. SPIE 74820, 74820E (2009).
[CrossRef]

Steinvall, O.

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path range gated imaging of static and moving targets,” Proc. SPIE 8379, 83790W (2012).
[CrossRef]

O. Steinvall, M. Elmqvist, and T. Chevalier, “Identification of handheld objects and human activities in active and passive imaging,” Proc. SPIE 8542, 854206 (2012).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path 1.5 μm range gated imaging close to ground,” Proc. SPIE 8037, 803703 (2011).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, H. Larsson, and M. Axelsson, “Laser imaging of small surface vessels and people at sea,” Proc. SPIE 7684, 768417 (2010).

E. Repasi, P. Lutzmann, O. Steinvall, M. Elmqvist, B. Göhler, and G. Anstett, “Advanced short-wavelength infrared range-gated imaging for ground applications in monostatic and bistatic configurations,” Appl. Opt. 48, 5956–5969 (2009).
[CrossRef]

O. Steinvall, P. Andersson, and M. Elmqvist, “Image quality for range-gated systems during different ranges atmospheric conditions,” Proc. SPIE 6396, 639607 (2006).
[CrossRef]

Tofsted, D. H.

R. L. Espinola, E. L. Jacobs, C. E. Halford, R. Vollmerhausen, and D. H. Tofsted, “Modeling the target acquisition performance of active imaging systems,” Opt. Express 15, 3816–3832 (2007).
[CrossRef]

D. H. Tofsted and S. G. O’Brien, “Simulation of atmospheric turbulence image distortion and scintillation effects impacting short wave infrared (SWIR) active imaging systems,” Proc. SPIE 5431, 160–171 (2004).

D. H. Tofsted, “Analytic improvements to the atmospheric turbulence optical transfer function,” Proc. SPIE 5075, 281–292 (2003).

Vollmerhausen, R.

Vollmerhausen, R. H.

R. G. Driggers, R. H. Vollmerhausen, N. Devitt, C. Halford, and K. J. Barnard, “Impact of speckle on laser range-gated shortwave infrared imaging system target identification performance,” Opt. Eng. 42, 738–746 (2003).
[CrossRef]

Welsh, B. M.

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

Zeisse, C.

G. Potvin, D. Dion, J. L. Forand, C. Zeisse, P. Frederickson, and K. Davidson, “Scintillation in the coastal atmospheric surface layer,” in 14th Symposium on Boundary Layer and Turbulence (American Meteorological Society, 2000), pp. 534–537.

Appl. Opt. (1)

Opt. Eng. (3)

D. Dayton, S. Browne, J. Gonglewski, S. Sandven, J. Gallegos, and M. Shilko, “Long-range laser illuminated imaging: analysis and experimental demonstrations,” Opt. Eng. 40, 1001–1009 (2001).
[CrossRef]

R. G. Driggers, R. H. Vollmerhausen, N. Devitt, C. Halford, and K. J. Barnard, “Impact of speckle on laser range-gated shortwave infrared imaging system target identification performance,” Opt. Eng. 42, 738–746 (2003).
[CrossRef]

C. E. Halford, A. L. Robinson, R. G. Driggers, and E. L. Jacobs, “Tilted surfaces in SWIR imagery: speckle simulation and a simple contrast model,” Opt. Eng. 46, 053201 (2007).
[CrossRef]

Opt. Express (1)

Proc. IEEE (2)

J. W. Goodman, “Some effects of target-induced scintillation on optical radar performance,” Proc. IEEE 53, 1688–1700 (1965).
[CrossRef]

R. L. Fante, “Electromagnetic beam propagation in turbulent media,” Proc. IEEE 63, 1669–1692 (1975).

Proc. SPIE (20)

L. Sjöqvist, L. Allard, O. Gustafsson, M. Henriksson, and M. Pettersson, “Turbulence effects in a horizontal propagation path close to ground: implications for optics detection,” Proc. SPIE 8187, 81870M (2011).
[CrossRef]

M. Henriksson and L. Sjöqvist, “Time-correlated single-photon counting laser radar in turbulence,” Proc. SPIE 8187, 81870N (2011).
[CrossRef]

O. Steinvall, P. Andersson, and M. Elmqvist, “Image quality for range-gated systems during different ranges atmospheric conditions,” Proc. SPIE 6396, 639607 (2006).
[CrossRef]

O. Steinvall, M. Elmqvist, and T. Chevalier, “Identification of handheld objects and human activities in active and passive imaging,” Proc. SPIE 8542, 854206 (2012).
[CrossRef]

J. D. O’Connor, B. L. O’Kane, C. K. Royal, K. L. Ayscue, D. E. Bonzo, and B. M. Nystrom, “Recognition of human activities using handheld thermal systems,” Proc. SPIE 3394, 51–61 (1998).
[CrossRef]

D. Bonnier, S. Lelievre, and L. Demers, “On the safe use of long-range laser active imager in the near-infrared for Homeland Security,” Proc. SPIE 6206, 62060A (2006).

O. David, R. Schneider, and R. Israeli, “Advance in active night vision for filling the gap in remote sensing,” Proc. SPIE 7482, 748203 (2009).

O. Steinvall, M. Elmqvist, K. Karlsson, H. Larsson, and M. Axelsson, “Laser imaging of small surface vessels and people at sea,” Proc. SPIE 7684, 768417 (2010).

D. C. Dayton, J. D. Gonglewski, J. B. Martin, M. A. Kovacs, J. C. Cardani, F. Maia, T. Aflalo, and M. L. Shilko, “Prediction and performance measures of atmospheric disturbances on an airborne imaging platform,” Proc. SPIE 5237, 117 (2004).
[CrossRef]

B. Göhler and P. Lutzmann, “Range accuracy of a gated-viewing system as a function of the number of averaged images,” Proc. SPIE 8542, 854205 (2012).
[CrossRef]

B. Göhler and P. Lutzmann, “Range accuracy of a gated-viewing system compared to a 3-D Flash LADA Runder different turbulence conditions,” Proc. SPIE 7835, 783504 (2010).
[CrossRef]

C. J. Carrano, “Progress in horizontal and slant-path imaging using speckle imaging,” Proc. SPIE 5001, 56–64 (2003).
[CrossRef]

O. Korotkova and L. C. Andrews, “Speckle propagation through atmospheric turbulence: effects of partial coherence of the target,” Proc. SPIE 4723, 73–84 (2002).
[CrossRef]

D. H. Tofsted and S. G. O’Brien, “Simulation of atmospheric turbulence image distortion and scintillation effects impacting short wave infrared (SWIR) active imaging systems,” Proc. SPIE 5431, 160–171 (2004).

E. Jacobs and R. L. Espinola, “Beam scintillation effects on identification performance with active imaging systems,” Proc. SPIE 5987, 598703 (2005).

D. H. Tofsted, “Analytic improvements to the atmospheric turbulence optical transfer function,” Proc. SPIE 5075, 281–292 (2003).

D. Edouart, P. Churouxa, and P. H. Flamant, “Burst illumination imaging lidar: intensity correlation function in the image plane,” Proc. SPIE 4723, 189–197 (2002).

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path 1.5 μm range gated imaging close to ground,” Proc. SPIE 8037, 803703 (2011).
[CrossRef]

O. Steinvall, M. Elmqvist, K. Karlsson, O. Gustafsson, and T. Chevalier, “Slant path range gated imaging of static and moving targets,” Proc. SPIE 8379, 83790W (2012).
[CrossRef]

K. O. S. Gustafsson, M. Henriksson, and L. Sjöqvist, “Wall induced turbulence distortions of optical measurements,” Proc. SPIE 74820, 74820E (2009).
[CrossRef]

Radio Sci. (1)

R. J. Hill, “Spectra of fluctuation in refractivity temperature, humidity, and the temperature-humidity cospectrum in the inertial and dissipation ranges,” Radio Sci. 13, 953–961 (1978).
[CrossRef]

Other (10)

G. Potvin, D. Dion, J. L. Forand, C. Zeisse, P. Frederickson, and K. Davidson, “Scintillation in the coastal atmospheric surface layer,” in 14th Symposium on Boundary Layer and Turbulence (American Meteorological Society, 2000), pp. 534–537.

B. Göhler and P. Lutzmann, “An analytical performance model for active imaging systems including slant-path applications,” 4th International Symposium on Optronics in Defence and Security, CD-ROM, Paris, France, 3–5 February2010.

R. R. Beland, “Propagation through atmospheric optical turbulence” in The Infrared and Electro-Optical Systems Handbook, J. S. Accetta and D. L. Shumaker, eds., Vol. 2 (SPIE, 1993).

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

Modeling of Active Imaging Systems, NATO RTO Technical report, TR-SET-072, Final report of task group 40, June 2009.

Obzerv images model ARGC-750, http://www.obzerv.com/night-vision-cameras/products/land-systems/argc-750/ .

N. S. Kopeika, A System Engineering Approach to Imaging (SPIE, 1998).

L. C. Andrews, R. L. Phillips, and C. Y. Hopen, Laser Beam Scintillation with Applications (SPIE Optical Engineering, 2001).

L. C. Andrews and R. L. Phillips, Laser Beam Propagation through Random Media (SPIE, Optical Engineering, 1998).

V. A. Banakh and V. L. Mironov, LIDAR in a Turbulent Atmosphere (Artech House, 1987).

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Figures (29)

Fig. 1.
Fig. 1.

Improvement in angular resolution versus sensor height for observing a ground target at 1.9 km range for different values of the parameter α.

Fig. 2.
Fig. 2.

Experimental arrangement with the 1.5 μm laser sensor in the cage and the elevated platform.

Fig. 3.
Fig. 3.

Edge and resolution charts. At 1920 m range the bar separation for the three largest bar groups corresponds to 26.3, 37.9, and 52.6 μrad, respectively. The ratio of length to width of all black bars is 15 and the linear scale factor between each bar group is 2. The size of the resolution test panel was 1.3×2.2m and the edge chart was about 2 m in square.

Fig. 4.
Fig. 4.

Drawing of the air field and the position of the experimental setup at the second day in the September 2010 campaign.

Fig. 5.
Fig. 5.

Cn2 as function of time measured using three different ultrasonic anemometer along the runway, 7 September 2010.

Fig. 6.
Fig. 6.

Comparison between measured Cn2 along the runway measured with the scintillometer (crosses) and measured with two ultrasonic anemometers halfway down the runway. Measurement performed 7 September 2010.

Fig. 7.
Fig. 7.

Two active imaging systems. Left, the Intevac tube with a F=1260mm telescope and a Saab laser range finder at 1.5 μm, and right, the Obzerve system (white box).

Fig. 8.
Fig. 8.

Person holding different objects to be identified statically and in conjunction with associated activities.

Fig. 9.
Fig. 9.

Example of Cn2 data registered using ultrasound anemometers at position A, AB=B2, and B during 14 June 2011.

Fig. 10.
Fig. 10.

Series of images for a low turbulence situation and a horizontal 1.9 km path at 2.1 m above ground. Left: a passive image of the whole FOV and next close-up images of the 2.2*1.3m bar pattern target, partly occluded by grass at the bottom. The angular resolution in the passive and active images are about equal and the improvement of active image averaging is mainly seen as an intensity smoothing. Time 14:54:11 on 7 September 2010. Mean turbulence from anemometers Cn2=1014m2/3.

Fig. 11.
Fig. 11.

Above the passive image of the scene and the bar target at about 16:42:30 on 7 September 2011 and below examples of single active frames from increasing heights between the time 16:44:24 to 17:11:47. At the higher elevations of the sensor there is a clear improvement in angular resolution, from about 50 μrad at 2.1 m to better than 18 μrad at 12.2 m.

Fig. 12.
Fig. 12.

Left: measured turbulence from the anemometer data, 7 September 2010. El. refers to the elevated anemometer (=sensor height) and Gr. to the mean value of the two ground-based anemometers. S1–S4 refer to different time series of measurements (S1: 14:49–15:11, S2: 15:49–16:19, S3: 16:42–17:12, S4: 17:24–17:46). Right: the resolution evaluated from the bar patterns for the corresponding time series.

Fig. 13.
Fig. 13.

Relation between angular jitter measured from the relative movement of two car lights and the angular resolution for single active images.

Fig. 14.
Fig. 14.

Measured turbulence from the anemometer data, 8 September 2010. El. refers to the elevated anemometer (=sensor height) and Gr. to the mean value of the two ground-based anemometers. S1–S4 refer to different time series of measurements (S1: 11:29–11:37, S2: 11:47–12:10, S3: 13:21–13:32, S4: 14:06–14:16). Note that the turbulence varies rather irregular with height on this day in opposite of the situation during 7 September 2010.

Fig. 15.
Fig. 15.

Angular resolution for different heights and three frames averaged. Left, active and right, passive operation.

Fig. 16.
Fig. 16.

Man at 876 m range with a toy weapon. The turbulence level around 1.5×1013m2/3. Note that the 1.5 μm images in the lower row seem to be somewhat less blurry than those from the visible-NIR region.

Fig. 17.
Fig. 17.

Images (three frame stabilized average) of active 1.5 μm (above) and passive SWIR images (below) of the resolution chart at 1.92 km range for the sensor heights of 1.6, 5.15, 7.65, 10.35, and 13.15 m, respectively (left to right). Focal length 1260 mm. Collection time period 3:52–4:11 PM, 14 June 2011.

Fig. 18.
Fig. 18.

Same as in Fig. 17 but at a later time (7:04–7:23 PM, 14 June 2011) when the ground turbulence measured by the scintillometer was between 47×1014m2/3.

Fig. 19.
Fig. 19.

Man with an RPG weapon in different positions at a range of 2 km. The active (above) and passive images were collected with different sensor heights (1.6, 5.15, 7.65, and 10.35 m). The measurements were collected between 6:07 and 6:33 PM 14 June 2011.

Fig. 20.
Fig. 20.

(Left two): a man with a shovel imaged at 1.5 μm and (right two) at 0.8 μm. Face reflection is very low at 1.5 μm. Both pair of images show the advantage of silhouette detection for visualizing the shovel. Range 850 m.

Fig. 21.
Fig. 21.

Above: the Obzerv system showing images at 2442 m of a man holding a weapon. Below: the same for the 1.5 μm system. Both sensors had a nominal angular resolution about 16 μrad. The sensors were placed 13 m above ground.

Fig. 22.
Fig. 22.

Two pairs of passive (left) and active images at 1.5 μm from the targets boards at 1130 m range. The smaller size white target board to the left was placed 10 m in front of the black and white target. Left, the sensor at 1.6 m above ground and right, the sensor at 7.65 m height. The ground value of the turbulence was between 13×1013m2/3.

Fig. 23.
Fig. 23.

Estimated angular resolution for single active images using the resolution chart versus edge response from the black and white board. The relatively large spread in data is probably due to the speckle noise.

Fig. 24.
Fig. 24.

Left diagram shows the good correspondence between the estimated image jitter from the relative motion of the two lights versus the theoretical values obtained from Eq. (5) using turbulence values from the scintillometer and the three anemometers. The R2 of the linear fits ranged between 0.62–0.92. Right shows calculated image jitter values for different turbulence values from the scintillometer and the anemometers. The anemometer positions A, AB, and B correspond approximately the positions A, B2, and B in Fig. 4.

Fig. 25.
Fig. 25.

Height variation of the horizontal (left) and vertical (right) image jitter. Note the increase in image jitter for the height of 10.35 m. The inserted circles reflect the jitter magnitude in an xy diagram.

Fig. 26.
Fig. 26.

Measured angular resolution for three frame stabilized active images versus measured image jitter.

Fig. 27.
Fig. 27.

Left: Measured angular resolution for three frame stabilized active images versus sensor height [black squares] versus theoretical values based on the conventional choice of α=4/3 (daytime) or α=2/3 (night time). Right: During the evening the choice of α=2/3 gave a good correspondence with the measured and theoretical angular resolution.

Fig. 28.
Fig. 28.

Measured angular resolution for three frame stabilized active images versus sensor height [black squares] versus theoretical values based on the conventional choice of α=4/3 (daytime) or α=2/3 (night time). The resolution was measured from the edge response of the black and white target board gave a much better correlation with the theory.

Fig. 29.
Fig. 29.

Probability of recognition and median time to response for different activities related to the normal use of the object listed on the x axis. A=active and P=passive imaging. Range 2 km with average sensor heights of 1.6 m (strong turbulence), 5 m (moderate), and 10 m (weak).

Equations (6)

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

Cn2(h)=Cn2(1)·hα,
ρsp=1.22λFD,
Csp=1M.
r0=2.1·[1.46k20LCn2(z)(1z/L)5/3dz]3/5,
σα2.9Cn2LD1/3,
MTF=exp[3.44·(λf/r0)5/3],

Metrics