9 June 2014 Mosaïc active imaging: direct physical modeling and image reconstruction
Author Affiliations +
Active imaging can be used for surveillance or target identification at long range and low visibility conditions. Its principle is based on the illumination of a scene with a pulsed laser which is then backscattered to the sensor. The signal to noise ratio and contrast of the object over the background are increased in comparison with passive imaging. Even though, range and field of view (FOV) are limited for a given laser power. A new active imaging system presented here aims at overcoming this limitation. It acquires the entire scene with a high-speed scanning laser illumination focused on a limited region, whereas at each scan the full frame active image is acquired. The whole image is then reconstructed by mosaicking all these successive images. A first evaluation of the performance of this system is conducted by using a direct physical model. This end-to-end model, realistic in terms of turbulence effects (scintillation, beam wandering ...), gives us a sequence of images a synthetic scenes. After presenting this model, a reconstruction method of the total scene is described. And the performances of this new concept are compared to those of a conventional flash active camera by using usual metrics ( SNR, MTF ...). For various mean laser powers, we quantify the gains expected in terms of range and field of view of this new concept.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Emmanuelle Thouin, Emmanuelle Thouin, Marie-Thérèse Velluet, Marie-Thérèse Velluet, Dominique Hamoir, Dominique Hamoir, Laurent Hespel, Laurent Hespel, François Malgouyres, François Malgouyres, Xavier Briottet, Xavier Briottet, "Mosaïc active imaging: direct physical modeling and image reconstruction", Proc. SPIE 9080, Laser Radar Technology and Applications XIX; and Atmospheric Propagation XI, 908007 (9 June 2014); doi: 10.1117/12.2053022; https://doi.org/10.1117/12.2053022

Back to Top