v.surf.tps & s.surf.tps

[Hangsheng Lin]

Dear GRASS users:

Is v.surf.tps available now? What is the general accuracy of s.surf.tps?
80%, 90%, or 50% (or whatever number) accurate? If v.surf.tps not ready
yet, to use s.surf.tps to interpolate a contour map to a full surface,
which of the following two approaches yields better accuracy? 1) use
v.to.rast to convert the vector file to a raster map -> use r.random to
sample, say 50% of the points -> use s.surf.tps to interpolate; 2) use
v.to.sites to extract points from the vector file -> use s.surf.tps to
interpolate. If I wish to assess the accuracy of the interpolation, how
should I do it? I am talking about a large area (~1/3 of Arkansas size and
a county size), no field data available for checking in my own study.

Any feedback will be greatly appreciated. Thanks in advance.

Sincerely,
Hangsheng Lin