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Applied Optics

Applied Optics


  • Editor: Joseph N. Mait
  • Vol. 53, Iss. 24 — Aug. 20, 2014
  • pp: 5531–5537

Synthetic aperture ladar imaging demonstrations and information at very low return levels

Zeb W. Barber and Jason R. Dahl  »View Author Affiliations

Applied Optics, Vol. 53, Issue 24, pp. 5531-5537 (2014)

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We present synthetic aperture ladar (SAL) imaging demonstrations where the return-signal level from the target is near the single-photon level per resolved pixel. Scenes consisting of both specular-point targets and diffuse-reflection, fully speckled targets are studied. Artificial retro-reflector-based phase references and/or phase-gradient-autofocus (PGA) algorithms were utilized for compensation of phase errors during the aperture motion. It was found that SAL images could reliably be formed with both methods even when the final max pixel intensity was at the few photon level, which means the SNR before azimuth compression is below unity. Mutual information-based comparison of SAL images show that average mutual information is reduced when the PGA is utilized for image-based phase compensation. The photon information efficiency of SAL and coherent imaging is discussed.

© 2014 Optical Society of America

OCIS Codes
(000.5490) General : Probability theory, stochastic processes, and statistics
(030.5290) Coherence and statistical optics : Photon statistics
(280.3400) Remote sensing and sensors : Laser range finder
(280.6730) Remote sensing and sensors : Synthetic aperture radar

ToC Category:
Imaging Systems

Original Manuscript: May 28, 2014
Revised Manuscript: July 23, 2014
Manuscript Accepted: July 25, 2014
Published: August 20, 2014

Zeb W. Barber and Jason R. Dahl, "Synthetic aperture ladar imaging demonstrations and information at very low return levels," Appl. Opt. 53, 5531-5537 (2014)

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