A 3D range imaging method using a LiDAR system includes sequentially generating multiple far field patterns to illuminate a target scene, each far field pattern including a plurality of light spots where each spot illuminates only a segment of a scene region unit that corresponds to a sensor pixel of the LiDAR receiver. Within each scene region unit, the multiple segments illuminated in different rounds are non-overlapping with each other, and they collectively cover the entire scene region unit or a part thereof. With each round of illumination, the signal light reflected from the scene is detected by the sensor pixels, and processed to calculate the depth of the illuminated segments. The calculation may take into consideration optical aberration which causes reflected light from an edge segment to be received by two sensor pixels. The depth data calculated from the sequential illuminations are combined to form a ranged image.