Filters on grids
At least some basic filters would be very convenient on grids: after the interpolation, we currently perform some basics checks on some specific fields (see http://models.slf.ch/p/meteoio/source/tree/HEAD/trunk/meteoio/Meteo2DInterpolator.cc starting line 148). Similarly, Snowpack forces all wind speeds less than 0.2 back to 0.2. And GeoTop needs the same thing in order to avoid very low wind speeds.
The proper way to address it would be a new section like [2D_filters] where we could configure which of these basic filters to use on grids (per parameter). The grids require filters that are different from the normal station filters: there are often no time series and the constraints are different (if all wind stations are sheltered, the max is different from the interpolated wind on a ridge).