Dr. Patti S. Gillespie Profile

Dr. Patti S. Gillespie

Retired

SPIE Involvement:

Author

Area of Expertise:

Optics

Proceedings Article | 20 October 2004 Paper

Target edge response

Mikhail Belen'kii, Patti Gillespie, Gary Gimmestad, Kevin Hughes, David Roberts, Vincent Rye, John Stewart, Jack Wood

Proceedings Volume 5550, (2004) https://doi.org/10.1117/12.566077

KEYWORDS: Imaging systems, Image quality, Modulation transfer functions, Cameras, Data acquisition, Point spread functions, Visible radiation, Scintillation, Atmospheric optics, Spatial resolution

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SPIE Journal Paper | 1 March 2004

Comparison of delta Eddington model calculations of contrast to measurements

Patti Gillespie

OE, Vol. 43, Issue 03, (March 2004) https://doi.org/10.1117/12.10.1117/1.1645255

KEYWORDS: Atmospheric modeling, Air contamination, Electro optical modeling, Scattering, Radiative transfer, Transmittance, Data modeling, Performance modeling, Aerosols, Clouds

Proceedings Article | 27 January 2004 Paper

Measurement of tilt anisoplanatism with discrete and extended sources

Mikhail Belen'kii, Kenneth Burgi, Patti Gillespie, Gary Gimmestad, Kevin Hughes, David Roberts, John Stewart, Jack Wood

Proceedings Volume 5160, (2004) https://doi.org/10.1117/12.507952

KEYWORDS: Imaging systems, Turbulence, Visible radiation, Sensors, Projection systems, Statistical analysis, Cameras, Data acquisition, Optical sensors, Scintillation

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A dual-band imaging system with variable aperture diameter was constructed and horizontal and vertical atmospheric tilt components were measured on a 1-km near-the-ground horizontal path using discrete and extended visible and JR sources. The spatial and temporal tilt statistics were estimated from the recorded data. Tilt structure function, which also characterizes v ariance of the p ointing error caused by anisoplanatism of t he track point to the aim point in the 1 aser projection system, for small angular separation decreases inverse proportionally to the aperture diameter D1 . The tilt structure function is insensitive to sensor vibration. For a point ahead angle of 0.45 mrad the daytime rms pointing enor caused by tilt anisoplanatism is 12 prad for D= 6 cm, and it is 5 prad for D= 40 cm. The tilt power spectral density agrees well with theory. Jt has the "-2/3" power slope, and the ratio of the two knee frequencies is equal to the inverse ratio of the aperture diameters. The tilt temporal conelation increases with the aperture diameter. The temporal conelation scale is 0.25 sec for D=6 cm and it is 1 sec for D= 40 cm. The C measurements made with discrete JR sources and an optical imager agree well with the measurements made with a scintillometer. The structure function for the lateral (Y) tilt exceeds that for the longitudinal (X) tilt, which is inconsistent with the theoretical prediction. We believe that heat-induced turbulence from the JR sources and a wind component parallel to the optical path degraded the measurements of the vertical tilt. Three mitigation techniques were considered including an increase of the aperture diameter, integration of the image edge over the edge angular extent, and averaging of multiple frames. A multi-frame averaging technique is known to be efficient for mitigation of the effects of turbulence induced scintillation and laser speckle. We found that by averaging multiple image frames one can mitigate the effects of tilt anisoplanatism as well. We also found that the edge response for a multi frame averaged image and a single frame image is the same. This allows us to conclude that a multi frame averaging technique for an extended object does not affect the system angular resolution.

Proceedings Article | 18 September 2001 Paper

Turbulence-induced edge image waviness: theory and experiment

Mikhail Belen'kii, John Stewart, Patti Gillespie

Proceedings Volume 4370, (2001) https://doi.org/10.1117/12.440076

KEYWORDS: Turbulence, Imaging systems, Cameras, Data modeling, Infrared imaging, Video, Analytical research, Astronomy, Image processing, Spherical lenses

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Proceedings Article | 7 July 1998 Paper

EOSAEL and PcEosael www.EOSAEL.com

Alan Wetmore, Patti Gillespie, John Schroeder

Proceedings Volume 3375, (1998) https://doi.org/10.1117/12.327145

KEYWORDS: Atmospheric modeling, Aerosols, Human-machine interfaces, Electro optical modeling, Atmospheric particles, Transmittance, Clouds, Analytical research, Atmospheric propagation, Scattering

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Conference Committee Involvement (19)

Automatic Target Recognition XXVII

10 April 2017 | Anaheim, CA, United States

Automatic Target Recognition XXVI

18 April 2016 | Baltimore, MD, United States

Automatic Target Recognition XXV

20 April 2015 | Baltimore, MD, United States

Infrared Sensors, Devices, and Applications IV

18 August 2014 | San Diego, California, United States

Automatic Target Recognition XXIV

5 May 2014 | Baltimore, MD, United States

Infrared Sensors, Devices, and Applications III

26 August 2013 | San Diego, California, United States

Automatic Target Recognition XXIII

29 April 2013 | Baltimore, Maryland, United States

Infrared Sensors, Devices, and Applications II

14 August 2012 | San Diego, California, United States

Automatic Target Recognition XXII

23 April 2012 | Baltimore, Maryland, United States

Infrared Sensors, Devices, and Applications

23 August 2011 | San Diego, California, United States

Automatic Target Recognition XXI

25 April 2011 | Orlando, Florida, United States

Automatic Target Recognition XX

5 April 2010 | Orlando, Florida, United States

Automatic Target Recognition XIX

13 April 2009 | Orlando, Florida, United States

Automatic Target Recognition XVIII

19 March 2008 | Orlando, Florida, United States

Automatic Target Recognition XVII

10 April 2007 | Orlando, Florida, United States

Automatic Target Recognition XVI

18 April 2006 | Orlando (Kissimmee), Florida, United States

Automatic Target Recognition XV

29 March 2005 | Orlando, Florida, United States

Automatic Target Recognition XIV

13 April 2004 | Orlando, Florida, United States

Automatic Target Recognition XIII

22 April 2003 | Orlando, Florida, United States

Showing 5 of 19 Conference Committees

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