Patent ID: 7003894

Claim:
A method for determining one or more surface profiles of an object, the method comprising the steps of: moving said object and a plurality of distance sensors relative to one another in a longitudinal direction, each one of said sensors arranged to measure the distance from itself to a surface of said object; measuring the relative longitudinal motion between said object and said distance sensors; for each surface, taking a plurality of distance measurements with each one of said sensors as said object and said sensors are moved relative one another, each one of said measurements taken simultaneously by all of said sensors, the sensors thereby providing distance measurement data reflecting a series of measurements, said distance measurement data having a first component relating to the particular surface profile features of said object and a second component relating to rigid body relative motions of said object in the measurement direction relative to said sensors; analyzing said measurement data to identify said rigid body relative motion component of said data; and determining said surface profile of said object by separating said rigid body relative motion component of said measurement data from said measurement data, leaving said surface profile feature component, wherein said rigid body motion component of said data is determined by identifying motion fluctuations of said object measured simultaneously at said sensors.