Short-range synthetic aperture imaging at 633 nm by digital holography.
We present an active optical synthetic aperture-imaging system. A phase-step digital holographic setup is used as a wavefront sensor in the far field. The overlap of the holograms enables the estimation and compensation of their relative positions and phase with a speckle cross-correlation algorithm. Experimental results on a short-range synthetic aperture setup at 633 nm are presented that are based on 128 x 128 holograms. The synthesis is executed in one direction by means of rotation of the object. Test images show a significant gain of resolution in the synthesis direction. Processing errors are estimated through experiment. Random processing errors of a synthetic pupil composed of 33 merged holograms are negligible, but biases induced by unknown optical aberrations ofthe reference wave induce defocusing and astigmatism.
Thales Research and Technology, Domaine de Corbeville, Orsay, France. renaud.binet@thalesgroup.com
Renaud
R
Binet
Joseph
J
Colineau
Jean-Claude
JC
Lehureau