1. A method for generating charged particle tomography images for a volume of interest (VOI) by a charged particle tomography system, the method comprising: collecting raw track data of tracks of cosmic-ray based charged particles passing through the VOI; grouping the collected raw track data into subsets of the tracks based on angular distribution of the tracks in a zenith direction in the raw track data by partitioning the collected raw track data into a first subset corresponding to large zenith angles and a second subset corresponding to small zenith angles; generating a set of images of the VOI based on the grouped subsets of the tracks; and combining information from at least the generated set of images to obtain an resulting image of the VOI.