#
#  filter and downsample the srtm15_V2.1.nc grid
#
ln -s ../SRTM15+V2.1.nc
gmt grdfilter SRTM15+V2.1.nc -D3 -Fg1m -I1m -Gtopo1.grd -V
gmt grdfilter topo1.nc -D3 -Fg2m -I2m -Gtopo2.nc -V
gmt grdfilter topo1.nc -D3 -Fg2m -I2m -Gtopo2.nc -V
gmt grdfilter topo2.nc -D3 -Fg5m -I5m -Gtopo5.nc -V
