Coherent High-Resolution Sparse Aperture Imaging Testbed

Coherent high resolution imaging of distant targets is a challenging problem whose complexity involves understanding of diffractive properties of the optical imaging system, speckle properties of target, statistical properties of the atmospheric refractive index variations, coherence properties of the light source and noise limtations of the detector array to mention a few major issues. In a coherent laser radar imaging system, the target is illuminated with a laser beam, and the scattered light wave from the target light wave is mixed with a local oscillator wave from the same source. The system is referred to as spatial heterodyne imaging system. The sparse aperture imaging approach is based on reducing the total irradiance collection area using smaller sub-apertures, while the resulting resolution of the sparse aperture imaging array is equivalent to an aperture larger than the sub-apertures. The Ladar and Optical Communications Institute (LOCI) currently has a prototype of the high resolution sparse aperture imaging testbed with an indoor and outdoor range capability. In collaboration with industry partners, academic institutions, and the government this testbed is becoming an innovative research tool in the field of high resolution coherent ladar imaging.