[gdal-dev] GetProjection returns empty string, python 3.7

[Nicolas Cadieux]

Hi,

With the following code, I get an empty string indicating the projection 
is not valid.

from osgeo import gdal, osr
raster_ds = gdal.Open(r"C:\temp\180922_WTE3.tif")
target_ds = 
driver.Create(r"c:\temp\output.tif",xsize=raster_ds_ncol,ysize=raster_ds_nrow,bands 
= 1,eType = gdal.GDT_Float32)
(array is a numpty array.)
raster_srs = osr.SpatialReference()
raster_srs.ImportFromWkt(raster_ds.GetProjectionRef())
target_ds.SetProjection(raster_srs.ExportToWkt())
target_ds.GetRasterBand(1).WriteArray(array)
raster_ds = None #close dataset
target_ds=None

Below is the result of gdal info from qgis. File appears to have a valid 
projection and is properly georeferenced in QGIS using other data sets. 
   Is this projection wrong or am I missing something in my python 
code?  The goal is to extract the projection from raster_ds set in order 
to apply to target_ds.  I can create the file, apply a geotransform but 
can't get the projection.  Can you help?

Thanks/merci!

Nicolas

QGIS version: 3.14.16-Pi
QGIS code revision: df27394552
Qt version: 5.11.2
GDAL version: 3.0.4
GEOS version: 3.8.1-CAPI-1.13.3
PROJ version: Rel. 6.3.2, May 1st, 2020
Processing algorithm…
Algorithm 'Raster information' starting…
Input parameters:
{ 'EXTRA' : '', 'INPUT' : 'C:/temp/180922_WTE3.tif', 'MIN_MAX' : False, 
'NOGCP' : False, 'NO_METADATA' : False, 'OUTPUT' : 'TEMPORARY_OUTPUT', 
'STATS' : False }

GDAL command:
gdalinfo C:/temp/180922_WTE3.tif
GDAL command output:
Warning 1: TIFFReadDirectory:Sum of Photometric type-related color 
channels and ExtraSamples doesn't match SamplesPerPixel. Defining 
non-color channels as ExtraSamples.

Driver: GTiff/GeoTIFF
Files: C:/temp/180922_WTE3.tif
Size is 1194, 2783
Coordinate System is:
PROJCRS["WGS 84 / UTM zone 18N",
BASEGEOGCRS["WGS 84",
DATUM["World Geodetic System 1984",
ELLIPSOID["WGS 84",6378137,298.257223563,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4326]],
CONVERSION["UTM zone 18N",
METHOD["Transverse Mercator",
ID["EPSG",9807]],
PARAMETER["Latitude of natural origin",0,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8801]],
PARAMETER["Longitude of natural origin",-75,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8802]],
PARAMETER["Scale factor at natural origin",0.9996,
SCALEUNIT["unity",1],
ID["EPSG",8805]],
PARAMETER["False easting",500000,
LENGTHUNIT["metre",1],
ID["EPSG",8806]],
PARAMETER["False northing",0,
LENGTHUNIT["metre",1],
ID["EPSG",8807]]],
CS[Cartesian,2],
AXIS["(E)",east,
ORDER[1],
LENGTHUNIT["metre",1]],
AXIS["(N)",north,
ORDER[2],
LENGTHUNIT["metre",1]],
USAGE[
SCOPE["unknown"],
AREA["World - N hemisphere - 78°W to 72°W - by country"],
BBOX[0,-78,84,-72]],
ID["EPSG",32618]]
Data axis to CRS axis mapping: 1,2
Origin = (459417.200000000011642,5028584.700000000186265)
Pixel Size = (0.050000000000000,-0.050000000000000)
Metadata:
AREA_OR_POINT=Area
TIFFTAG_XRESOLUTION=1
TIFFTAG_YRESOLUTION=1
Image Structure Metadata:
INTERLEAVE=BAND
Corner Coordinates:
Upper Left ( 459417.200, 5028584.700) ( 75d31' 7.03"W, 45d24'34.58"N)
Lower Left ( 459417.200, 5028445.550) ( 75d31' 6.99"W, 45d24'30.07"N)
Upper Right ( 459476.900, 5028584.700) ( 75d31' 4.28"W, 45d24'34.59"N)
Lower Right ( 459476.900, 5028445.550) ( 75d31' 4.24"W, 45d24'30.08"N)
Center ( 459447.050, 5028515.125) ( 75d31' 5.63"W, 45d24'32.33"N)
Band 1 Block=1194x1 Type=UInt16, ColorInterp=Red
...
Band 288 Block=1194x1 Type=UInt16, ColorInterp=Undefined