The numerical hole filling procedure, however, modifies the surface topography so that
roughness measurements become dubious from the data. Moreover, the procedure is time
consuming with coupling of repeated scans to cover the whole surface. Together with the
numerical hole filling- and the reference plane selection procedures this presumably also
introduces the kind of vertical artefacts seen several places in the surface scans in Figure 2. In
addition to the above mentioned work with the concrete ice abrasion machine we are therefore
at present also developing a new abrasion measurement system based on laser.