Patent ID: 7359039

Claim:
A method for measuring the distance to a target object based on a radiant energy time of travel to and from the target object and a measuring device, the method comprising: generating a wave of outgoing radiant energy pulses having a substantially stable period for providing a wave of reflected pulses, said outgoing pulses having a duration shorter than said period; measuring reflected energy from said pulse wave over a scanning window that has a shorter effective duration than said time of travel; setting an offset between said outgoing pulses and said scanning window in order to capture reflected pulses at desired positions within said scanning window; recording said offset and reflected energy data when said outgoing wave is reflected from a reference surface and said offset has been set to capture reflected pulses in a first time position in said scanning window and provide a first reference pulse data set, said reference surface being a fixed distance from a point of measuring reflected energy; recording offset and reflected energy data when said outgoing wave is reflected from said reference surface and said offset has been set to capture reflected pulses in a second time position in said scanning window and provide a second reference pulse data set, said second position being different than said first position; recording offset and reflected energy data when said outgoing wave is reflected from the target object and said offset has been set to capture reflected pulses in said scanning window and provide an object pulse data set; and calculating said distance between the device and the target object according to said first reference data set, said second reference data set and said object data set.