DETECTION AND RANGING METHODS AND SYSTEMS

A method for detecting a distance to an object, comprising: providing a lighting system having at least one pulse width modulated visible-light source for illumination of a field of view; emitting an illumination signal for illuminating said field of view for a duration of time y using said visible-light source at a time t, said time t typically being a center of a transition from a non-illuminated state to an illuminated state of said field of view, for at least one pulse; starting an optical sensor for integrating a reflection energy captured by said visible-light source, of a reflection of said illumination signal, for a first time period at a time t-x of a first one of said at least one pulse; stopping said optical sensor for said first time period at a time t+x for said first one of said at least one pulse and determining a first integration value for said first time period; starting said optical sensor for integrating said reflection energy captured by said visible-light source, of said reflection of said illumination signal, for a second time period at a time t+y-x for a second one of said at least one pulse, said second one being one of said first one and another one of said at least one pulse, y being greater than x; stopping said optical sensor for said second time period at a time t+y+x for said second one of said at least one pulse and determining a second integration value for said second time period; calculating a difference value between said first integration value and said second integration value; determining a propagation delay value proportional to said difference value; determining said distance to said object from said propagation delay value.