An imaging system comprising: a main detection unit, configured to acquire reflection-based images of an environment to be imaged, said main detection unit comprising: at least one light source, configured to emit light pulses toward said environment; and at least one camera comprising at least one gated image sensor, configured to receive reflections of said light pulses reflected from a selected depth of field in said environment, and to convert said reflections into a reflection-based image (170, 200, 230), whereby the main detection unit operates using active gated imaging such that the activation of said camera is synchronized with the emission of said light pulses by said light source in order to image a particular DOF, an auxiliary detection unit, configured to acquire emission-based images of said environment, said auxiliary detection unit comprising at least one thermal sensor, configured to detect infrared radiation emitted from said environment, and to generate an emission-based image (180, 210, 240), and an image processor, configured to process and to detect at least one region of interest in at least one acquired reflection-based image (170, 200, 230) and at least one acquired emission-based image (180, 210, 240); and a controller, configured to synchronize the emission of said light pulses by said light source with exposure of said camera for implementing active gated imaging by said main detection unit, the controller further configured to selectively modify at least one operating parameter of said main detection unit to direct said main detection unit to obtain further reflection-based images in a particular DOF based on detection of a potential object in a region of interest in an emission-based image (180, 210, 240) obtained from said auxiliary detection unit, to reduce potential object candidates in the further reflection-based images, such that said image processor is configured to detect at least one object of interest in a subsequent reflection-based image (170, 200, 230) acquired by the main detection unit. a main detection unit, configured to acquire reflection-based images of an environment to be imaged, said main detection unit comprising: at least one light source, configured to emit light pulses toward said environment; and at least one camera comprising at least one gated image sensor, configured to receive reflections of said light pulses reflected from a selected depth of field in said environment, and to convert said reflections into a reflection-based image (170, 200, 230), whereby the main detection unit operates using active gated imaging such that the activation of said camera is synchronized with the emission of said light pulses by said light source in order to image a particular DOF, at least one light source, configured to emit light pulses toward said environment; and at least one camera comprising at least one gated image sensor, configured to receive reflections of said light pulses reflected from a selected depth of field in said environment, and to convert said reflections into a reflection-based image (170, 200, 230), whereby the main detection unit operates using active gated imaging such that the activation of said camera is synchronized with the emission of said light pulses by said light source in order to image a particular DOF, an auxiliary detection unit, configured to acquire emission-based images of said environment, said auxiliary detection unit comprising at least one thermal sensor, configured to detect infrared radiation emitted from said environment, and to generate an emission-based image (180, 210, 240), and an image processor, configured to process and to detect at least one region of interest in at least one acquired reflection-based image (170, 200, 230) and at least one acquired emission-based image (180, 210, 240); and a controller, configured to synchronize the emission of said light pulses by said light source with exposure of said camera for implementing active gated imaging by said main detection unit, the controller further configured to selectively modify at least one operating parameter of said main detection unit to direct said main detection unit to obtain further reflection-based images in a particular DOF based on detection of a potential object in a region of interest in an emission-based image (180, 210, 240) obtained from said auxiliary detection unit, to reduce potential object candidates in the further reflection-based images, such that said image processor is configured to detect at least one object of interest in a subsequent reflection-based image (170, 200, 230) acquired by the main detection unit.