Recovering Occluded Scene Depth and Reflectance Maps in Dense Fog

A pulsed laser may illuminate a scene that is obscured by dense, dynamic and heterogeneous fog. Light may reflect back to a time-resolved camera. Each pixel of the camera may detect a single photon during each frame. The imaging system may accurately determine reflectance and depth of the fog-obscured target, without any calibration or prior knowledge of the scene depth. The imaging system may perform a probabilistic algorithm that exploits the fact that times of arrival of photons reflected from fog have a Gamma distribution that is different than the Gaussian distribution of times of arrival of photons reflected from the target. The probabilistic algorithm may take into account times of arrival of all types of measured photons, including scattered and un-scattered photons.