def __buildvrt(archives, vrtfile, pattern, vsi, extent, nodata=None, srs=None):
locals = [vsi + x for x in dissolve([finder(x, [pattern]) for x in archives])]
if nodata is None:
with Raster(locals[0]) as ras:
nodata = ras.nodata
opts = {'outputBounds': (extent['xmin'], extent['ymin'],
extent['xmax'], extent['ymax']),
'srcNodata': nodata}
if srs is not None:
opts['outputSRS'] = crsConvert(srs, 'wkt')
gdalbuildvrt(src=locals, dst=vrtfile,
options=opts)
def dem_create(src,
dst,
t_srs=None,
tr=None,
resampling_method='bilinear',
geoid_convert=False,
geoid='EGM96'):
"""
create a new DEM GeoTiff file and optionally convert heights from geoid to ellipsoid
Parameters
----------
src: str
the input dataset, e.g. a VRT from function :func:`dem_autoload`
dst: str
the output dataset
t_srs: None, int, str or osr.SpatialReference
A target geographic reference system in WKT, EPSG, PROJ4 or OPENGIS format.
See function :func:`spatialist.auxil.crsConvert()` for details.
Default (None): use the crs of ``src``.
tr: None or tuple
the target resolution as (xres, yres)
resampling_method: str
the gdalwarp resampling method; See `here <https://gdal.org/programs/gdalwarp.html#cmdoption-gdalwarp-r>`_
for options.
geoid_convert: bool
convert geoid heights?
geoid: str
the geoid model to be corrected, only used if ``geoid_convert == True``; current options:
* 'EGM96'
Returns
-------
"""
with Raster(src) as ras:
nodata = ras.nodata
epsg_in = ras.epsg
if t_srs is None:
epsg_out = epsg_in
else:
epsg_out = crsConvert(t_srs, 'epsg')
gdalwarp_args = {
'format': 'GTiff',
'multithread': True,
'srcNodata': nodata,
'dstNodata': nodata,
'srcSRS': 'EPSG:{}'.format(epsg_in),
'dstSRS': 'EPSG:{}'.format(epsg_out),
'resampleAlg': resampling_method
}
if tr is not None:
gdalwarp_args.update({'xRes': tr[0], 'yRes': tr[1]})
if geoid_convert:
if gdal.__version__ < '2.2':
raise RuntimeError('geoid conversion requires GDAL >= 2.2;'
'see documentation of gdalwarp')
if geoid == 'EGM96':
gdalwarp_args['srcSRS'] += '+5773'
else:
raise RuntimeError('geoid model not yet supported')
try:
message = 'creating mosaic'
crs = gdalwarp_args['dstSRS']
if crs != 'EPSG:4326':
message += ' and reprojecting to {}'.format(crs)
print(message)
gdalwarp(src, dst, gdalwarp_args)
except RuntimeError as e:
if os.path.isfile(dst):
os.remove(dst)
errstr = str(e)
if 'Cannot open egm96_15.gtx' in errstr:
addition = '\nplease refer to the following site for instructions ' \
'on how to use the file egm96_15.gtx (requires proj.4 >= 5.0.0):\n' \
'https://gis.stackexchange.com/questions/258532/' \
'noaa-vdatum-gdal-variable-paths-for-linux-ubuntu'
raise RuntimeError(errstr + addition)
else:
raise e
