Experimental demonstrations of optical synthetic aperture imaging using spatial heterodyne interferometry have been achieved at the Lockheed Martin Advanced Technology Center in Palo Alto, CA. In laboratory experiments, a reflective binary star scene and an Air Force resolution bar target were illuminated and imaged by a 532 nm laser and an afocal telescope. The real aperture diffraction limit in the horizontal direction was 65 microRadians. Complex pupil information was obtained by mixing the scattered return light from the target with light from an off-axis local oscillator, thus forming a linear fringe pattern on a CCD array placed at the pupil plane. Fourier transform methods were used to extract pupil amplitude and phase. By translating the real aperture pupil, collecting data at different locations, and extracting and combining the pupil data, a synthetic aperture twice the real aperture size was created. In the reconstructed image resulting from the synthetic aperture pupil data, features down to 32 microRadians were clearly resolved.

Date Published: 1 September 2009
PDF: 8 pages
Proc. SPIE 7468, Adaptive Coded Aperture Imaging, Non-Imaging, and Unconventional Imaging Sensor Systems, 74680Q (1 September 2009); doi: 10.1117/12.824501

Published in SPIE Proceedings Vol. 7468:
Adaptive Coded Aperture Imaging, Non-Imaging, and Unconventional Imaging Sensor Systems
David P. Casasent; Stanley Rogers; Jean J. Dolne; Thomas J. Karr; Victor L. Gamiz, Editor(s)