US Patent 11536836 Time-of-flight independent of object reflectivity

A method includes flashing an object with a first illumination pulse at a first illumination power level, flashing the object with a second illumination pulse at a second illumination power level different from the first illumination power level, integrating at least a portion of a first return pulse which is the first illumination plus returning from the object to determine a first return time, and integrating at least a portion of a second return pulse which is the second illumination pulse returning from the object to determine a second return time. The method includes using the first and second return times to determine distance to the object independent of reflectivity of the object.