Model of airborne imaging system with complex modulated beam of illumination, adaptive to wavy surface

摘要

New principles of design of imaging system through the rough surface are offered. These principles allow to lower negative influence of surface wavy and multiple scattering in water on the spatial resolution. The system model in which the image of underwater objects is formed at by means of angular scanning by an illumination beam is considered. Image distortions in such system are caused basically by random changes of a refraction angle of a laser beam on a surface and can be eliminated, if the true direction of an input of a beam in water is known. We suggest taking the information on refraction angle of a beam from angular distribution of backscattering signal of water layer. Such information can be received by means of receivers with sensitivity linearly vary across the field of view. The knowledge of true position of a beam of illumination on object allows receiving the image not deformed by wavy. We suggest reducing influence of multiplayer scattering in water by means of application of high-frequency modulation of beam power and the matched processing in reception system. Use of a complex signal modulation allows keeping the good resolution on depth and the resolution in a horizontal plane to rise. Thus, the combination of a method of definition of a refraction angle of a beam and modulation of a beam by a high-frequency complex signal gives an essential gain in the resolution of airborne imaging system.