I am trying to convert an imagine file with meter vertical and horizontal units to a foot projection. Using gdalwarp, I am able to convert the horizontal but the vertical units stays in meters. I did not see an option to either convert the z values or put the vertical unit type in the header.
I noticed gdal_grid has a -z_multiply option, but I would rather not have another step if possible.
Here is an example of my gdalwarp command:
gdalwarp -t_srs ESRI::C:\state_plane_foot.prj -tr 3.3 3.3 -r average -of HFA C:\utm_meter.img C:\state_plane_foot.img