A light ranging system can include a laser device and an imaging device having photosensors. The laser device illuminates a scene with laser pulse radiation that reflects off of objects in the scene. The reflections can vary greatly depending on the reflecting surface shape and reflectivity. The signal measured by photosensors can be filtered with a number of matched filter designed according to profiles of different reflected signals. A best matched filter can be identified, and hence information about the reflecting surface and accurate ranging information can be obtained. The laser pulse radiation can be emitted in coded pulses by allowing weights to different detection intervals. Other enhancements include staggering laser pulses and changing an operational status of photodetectors of a pixel sensor, as well as efficient signal processing using a sensor chip that includes processing circuits and photosensors.