Spike Removal is a generalisation of the algorithm given in EN15610:2009 section 7.2.Normally, the data displayed is based on the corrugation profile of the rail as measured. Optionally, the data displayed (and analysed) can be pre-processed to remove ‘spikes’ in the measured profile. Spikes can be measurement artefacts or can be caused by discontinuities in the measured rail.To turn on spike removal, select Filters|Spike Processing… from the menu. A dialog panel appears which enables you to turn spike processing on and off: