NTv2 format supports only single-precission floating point data. GRASS double-precision DCELL data need to be reduced to FCELL before export, eg. using r.mapcalc float()
function.
The user should adjust the region and resolution to match the input raster maps before export, using g.region.
PROJ.4 and the software that depend on it, including GDAL, GRASS, QGIS, assume the NTv2 grid's destination coordinate system to be WGS84. The metadata values in the grid's header set with majort
, minort
, systemt
parameters are ignored, same as the input coordinate system parameters (majorf
, minorf
, systemf
). They are for documentation purposes only.
The CREATED
and UPDATED
output grid's metadata fields are set to, respectively, current date and time, in YYYYMMDD and HHMMSS format.
Last changed: $Date$