Surface distance determination using reflected light

A distance between a light source and a surface may be determined by emitting pulses of light from the light source and measuring an intensity of the light after the light reaches the surface. To determine a true distance, aliased distances, which are outside of a known distance segment, are disregarded. The distance segment may be defined by a modulation period of light emitted by the light source. The distance segment may be determined based on a ratio of a measured intensity of light captured during a first time interval and a second time interval, and a comparison of other types of evidence data that identifies a correct distance segment. The evidence data may include data associated with the amplitude (intensity) of the light captured, temporal variations in data, and/or analysis data collected from other surfaces that are adjacent to the surface.