title: Synthetic-aperture imaging laser radar: laboratory demonstration and signal processing.
abstract: The spatial resolution of a conventional imaging laser radar system is constrained by the diffraction limit of the telescope's aperture. We investigate a technique known as synthetic-aperture imaging laser radar (SAIL), which employs aperture synthesis with coherent laser radar to overcome the diffraction limit and achieve fine-resolution, long-range, two-dimensional imaging with modest aperture diameters. We detail our laboratory-scale SAIL testbed, digital signal-processing techniques, and image results. In particular, we report what we believe to be the first optical synthetic-aperture image of a fixed, diffusely scattering target with a moving aperture. A number of fine-resolution, well-focused SAIL images are shown, including both retroreflecting and diffuse scattering targets, with a comparison of resolution between real-aperture imaging and synthetic-aperture imaging. A general digital signal-processing solution to the laser waveform instability problem is described and demonstrated, involving both new algorithms and hardware elements. These algorithms are primarily data driven, without a priori knowledge of waveform and sensor position, representing a crucial step in developing a robust imaging system.
authors.affiliation: Aerospace Corporation, P.O. Box 92957, Los Angeles, California 90009-2957, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Beck
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Buck
authors.forename: Walter F
authors.initials: WF
authors.lastname: Buell
authors.forename: Richard P
authors.initials: RP
authors.lastname: Dickinson
authors.forename: David A
authors.initials: DA
authors.lastname: Kozlowski
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Marechal
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Wright