The present invention can provide an apparatus operable to determine a signature from an article arranged in a reading volume. The apparatus can comprise a generator operable to generate and sequentially direct a focussed noncoherent beam onto each of a plurality of different regions of the reading volume; a detector arrangement operable to collect a set comprising groups of data points from signals obtained when the beam scatters from the different regions of the reading volume, wherein different ones of the groups of data points relate to scatter from the respective different regions of the reading volume; and a data acquisition and processing module operable to determine a signature of the article from the set of groups of data points.