| Autor: |
Beck, Steven M., Buck, Joseph R., Buell, Walter F., Dickinson, Richard P., Kozlowski, David A., Marechal, Nicholas J., Wright, Timothy J. |
| Zdroj: |
Applied Optics; December 2005, Vol. 44 Issue: 35 p7621-7629, 9p |
| Abstrakt: |
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. |
| Databáze: |
Supplemental Index |
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