Apologies for my first posting to this group, if this isn't really the best
place
to pose this question. I also posted this question in the 'GMT' (Generic Mapping Tools)
newsgroup, since that is the primary tool that I am attempting to use (so far, no
responses). However, the actual error message that I am getting (see below)is
a 'NetCDF'
error. Can anyone help? Would the newest version (4.0+) help me?
...
Hello all! I posted a similar question, apparently 4 years ago. I have now
resumed my quest for using GMT to create topo maps using 0.75 arcsecond (or
is it 1 arcsecond?) Canadian CDED data. I am doing this since the SRTM data
currently available for non-US locations is limited to 30 arcsecond (90
meter) accuracy.
This good page indirectly confirms that this *should* be possible, since
conversion to SRTM format (and therefore GMT maps) is implied for the CDED data:
http://www.cplus.org/rmw/dataen.html
After registering, I download a zip file containing relevant files:
# unzip -l 062G01.zip
Archive: 062G01.zip
Length Date Time Name
-------- ---- ---- ----
13521 07-06-07 10:36 cded_062g01_2_0_fgdc_en.xml
33703 07-06-07 10:36 cded_062g01_2_0_fgdc_en.html
15169 07-06-07 10:36 cded_062g01_2_0_fgdc_fr.xml
36134 07-06-07 10:36 cded_062g01_2_0_fgdc_fr.html
9839616 07-06-07 10:36 062g01_0200_deme.dem
9839616 07-06-07 10:36 062g01_0200_demw.dem
-------- -------
19777759 6 files
My tests involve using '062g01_0200_demw.dem'.
I convert this to GMT 'grd' data format using two different techniques:
1) Python program written by Norman Vine
(http://www.vso.cape.com/~nhv/files/python/gdal/gdal2grd.py):
python gdal2grd.py 062g01_0200_demw.dem
2) GDAL utility:
gdal_translate -of GMT 062g01_0200_demw.dem 062g01_0200_demw.gdal_translate.grd
Both appear to be successful, and generate apparently valid GMT 'grd' files:
# grdinfo 062g01_0200_demw.gdal2grd.grd
062g01_0200_demw.gdal2grd.grd: Title: no_title
062g01_0200_demw.gdal2grd.grd: Command: created by NumPy
062g01_0200_demw.gdal2grd.grd: Remark:
062g01_0200_demw.gdal2grd.grd: Gridline node registration used
062g01_0200_demw.gdal2grd.grd: Grid file format: cf (# 10)
062g01_0200_demw.gdal2grd.grd: x_min: -98.5001 x_max: -98.2499 x_inc:
0.000208333 name: degrees nx: 1201
062g01_0200_demw.gdal2grd.grd: y_min: 48.9999 y_max: 49.2501 y_inc:
0.000208333 name: degrees ny: 1201
062g01_0200_demw.gdal2grd.grd: z_min: -32767 z_max: 505 name: meters
062g01_0200_demw.gdal2grd.grd: scale_factor: 1 add_offset: 0
# grdinfo 062g01_0200_demw.gdal_translate.grd
062g01_0200_demw.gdal_translate.grd: Title:
062g01_0200_demw.gdal_translate.grd: Command:
062g01_0200_demw.gdal_translate.grd: Remark:
062g01_0200_demw.gdal_translate.grd: Gridline node registration used
062g01_0200_demw.gdal_translate.grd: Grid file format: cs (# 8)
062g01_0200_demw.gdal_translate.grd: x_min: -98.5001 x_max: -98.2499 x_inc:
0.000208333 name: meters nx: 1201
062g01_0200_demw.gdal_translate.grd: y_min: 48.9999 y_max: 49.2501 y_inc:
0.000208333 name: meters ny: 1201
062g01_0200_demw.gdal_translate.grd: z_min: 339 z_max: 505 name: meters
062g01_0200_demw.gdal_translate.grd: scale_factor: 1 add_offset: 0
However, when I attempt to actually draw GMT maps using these 'grd' files,
things break down quickly. It chokes at one of the first steps i.e. using
'grdgradient':
# grdgradient 062g01_0200_demw.gdal2grd.grd -A0 -Ne0.6 -Gcded_i.grd -V
GMT_grd_is_global: no!
GMT_boundcond_param_prep determined edgeinfo: gn = 0, gs = 0, nxp = 0, nyp = 0
GMT_grd_is_global: no!
grdgradient: NetCDF: Index exceeds dimension bound
[062g01_0200_demw.gdal2grd.grd]
]# grdgradient 062g01_0200_demw.gdal_translate.grd -A0 -Ne0.6 -Gcded_i.grd -V
GMT_grd_is_global: no!
GMT_boundcond_param_prep determined edgeinfo: gn = 0, gs = 0, nxp = 0, nyp = 0
GMT_grd_is_global: no!
grdgradient: NetCDF: Index exceeds dimension bound
[062g01_0200_demw.gdal_translate.grd]
I am at my wit's end! I am so close, but it just doesn't work. Can anyone
help?
Thanks
