Long range 3D active imagery with a scanned single element 1.5 μm coherent lidar system

摘要

Recent progress on the development of a long-range, high-resolution 3D active imaging sensor is described. Diffraction limited angular resolution of 20μrad and sub-metre down range resolution are demonstrated at stand-off ranges of 8km. A scanned single pixel arrangement was employed using an all-fiber coherent lidar operating in a chirp-pulse-compression mode. The monostatic antenna had an aperture of 150mm and the image was built up using a piezoelectric tip/tilt stage positioned prior to the final expansion of the beam. Transmit/receive multiplexing was achieved with a fiber optic circulator. Examples of recently acquired images consisting of 150x150 pixels with 1000, 30cm range cells per pixel at a stand-off range 8km are presented.