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 positioned on the head assembly , the lens positioned on a front side of the motherboard ; and a mirror positioned on the head assembly , the mirror positioned on a rear side of the motherboard ; wherein the lens comprises an emitter lens and a detector lens , the emitter lens and the detector lens being positioned adjacent one another; and the mirror 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 positioned on the head assembly , the lens 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 positioned on the head assembly , the lens positioned on a front side of the motherboard ; and a mirror positioned on the head assembly , the mirror positioned on a rear side of the motherboard ; wherein the lens comprises an emitter lens and a detector lens , the emitter lens and the detector lens being positioned adjacent one another; and the mirror 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. <EOS>