A LiDAR-based sensor system comprising: a base; a head assembly; a rotary component configured to rotate the head assembly with respect to the base, the rotation of the head assembly defining an axis of rotation; an electrical motherboard carried in the head assembly, the motherboard defining plane that is substantially parallel to the rotation axis; a plurality of photon transmitters mounted to a plurality of emitter circuit boards; and a plurality of detectors mounted to a plurality of detector circuit boards; the sensor system being characterized in that: the plurality of emitter circuit boards are mounted directly to the motherboard along a first axis substantially parallel to the axis of rotation; the plurality of detector circuit boards are mounted directly to the motherboard along a second axis substantially parallel to the axis of rotation; and a lens (50,52) positioned on the head assembly, the lens (50,52) positioned on a front side of the motherboard; and a mirror (40,42) positioned on the head assembly, the mirror (40,42) positioned on a rear side of the motherboard; wherein the lens (50,52) comprises an emitter lens and a detector lens, the emitter lens and the detector lens being positioned adjacent one another; and the mirror (40,42) comprises an emitter mirror and a detector mirror; wherein the emitter mirror is positioned within the head assembly to reflect light from the plurality of photon transmitters through the emitter lens, and the detector mirror is positioned within the head to reflect light received through the detector lens toward the plurality of detectors. a base; a head assembly; a rotary component configured to rotate the head assembly with respect to the base, the rotation of the head assembly defining an axis of rotation; an electrical motherboard carried in the head assembly, the motherboard defining plane that is substantially parallel to the rotation axis; a plurality of photon transmitters mounted to a plurality of emitter circuit boards; and a plurality of detectors mounted to a plurality of detector circuit boards; the sensor system being characterized in that: the plurality of emitter circuit boards are mounted directly to the motherboard along a first axis substantially parallel to the axis of rotation; the plurality of detector circuit boards are mounted directly to the motherboard along a second axis substantially parallel to the axis of rotation; and a lens (50,52) positioned on the head assembly, the lens (50,52) positioned on a front side of the motherboard; and the plurality of emitter circuit boards are mounted directly to the motherboard along a first axis substantially parallel to the axis of rotation; the plurality of detector circuit boards are mounted directly to the motherboard along a second axis substantially parallel to the axis of rotation; and a lens (50,52) positioned on the head assembly, the lens (50,52) positioned on a front side of the motherboard; and a mirror (40,42) positioned on the head assembly, the mirror (40,42) positioned on a rear side of the motherboard; wherein the lens (50,52) comprises an emitter lens and a detector lens, the emitter lens and the detector lens being positioned adjacent one another; and the mirror (40,42) comprises an emitter mirror and a detector mirror; wherein the emitter mirror is positioned within the head assembly to reflect light from the plurality of photon transmitters through the emitter lens, and the detector mirror is positioned within the head to reflect light received through the detector lens toward the plurality of detectors.