In contrast with naming rules used with profile parameters, prefixes of the areal parameters do not reflect the nature of the surface, distinguishing between roughness and waviness. In the ISO 25178 standard, all areal parameters start with the upper case letter S or the upper case letter V. MountainsMap® version 5.0 was the first commercial package to offer, in 2007, the complete set of field parameters defined in the draft ISO 25178. Later, release of MountainsMap in 1996 and publication of the SurfStand report, contributed to establish standard ways to calculate areal surface texture parameters.
Figure sf with slopes in terramodel software#
Stout and his collaborators at Birmingham, and with the release of DigiSurface software on Macintosh in 1993, developed by Digital Surf and later adapted for Taylor Hobson's Form Talysurf under the name Talymap. Nonetheless good practices were later disseminated, notably thanks to publications by Pr.
The naming rules for the parameters were also derived from the 2D parameters (sRa, sWa.) and were calculated using proprietary algorithms leading to different values on different instruments. In the absence of official documentation, the manufacturers made up solutions that were more or less felicitous, with surface parameters sometimes calculated as the simple mean of profile parameters evaluated for each line on the surface, or for radial profiles extracted from a circle with its origin at the centre of the image. The first manufacturers of areal surface texture measurement instruments initially proposed characterization methods that were mainly based upon a simple extrapolation of 2D methods.