Closed bjorn-iversen closed 2 years ago
Hi there, sorry you're having this issue!
For starters, here's what my .vrt
file for that dataset on the public API looks like (a .vrt
file is in XML format):
<VRTDataset rasterXSize="75841" rasterYSize="72001">
<SRS>GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433],AUTHORITY["EPSG","4326"]]</SRS>
<GeoTransform> -3.6000000120000003e+01, 1.0416666699999985e-03, 0.0000000000000000e+00, 9.0000000290040006e+01, 0.0000000000000000e+00, -1.0416666699999985e-03</GeoTransform>
<VRTRasterBand dataType="Float32" band="1">
<NoDataValue>99</NoDataValue>
<ColorInterp>Gray</ColorInterp>
<ComplexSource>
<SourceFilename relativeToVRT="1">../emod-2018/A1.tif</SourceFilename>
<SourceBand>1</SourceBand>
<SourceProperties RasterXSize="9492" RasterYSize="9012" DataType="Float32" BlockXSize="9492" BlockYSize="1" />
<SrcRect xOff="0" yOff="0" xSize="9492" ySize="9012" />
<DstRect xOff="0" yOff="0" xSize="9492" ySize="9012" />
<NODATA>99</NODATA>
</ComplexSource>
<ComplexSource>
<SourceFilename relativeToVRT="1">../emod-2018/A2.tif</SourceFilename>
the <SRS>
tag refers to the coordinate reference system (CRS) that the error message says is missing. Could you check if your .vrt
file has that?
The next thing to check is that the source files (A1.asc
or A1.tif
) have correct CRS info. If you run
gdalinfo A1_2018.asc
you should get a section called Coordinate System is
Driver: GTiff/GeoTIFF
Files: A1.tif
Size is 9492, 9012
Coordinate System is:
GEOGCRS["WGS 84",
DATUM["World Geodetic System 1984",
ELLIPSOID["WGS 84",6378137,298.257223563,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
CS[ellipsoidal,2],
AXIS["geodetic latitude (Lat)",north,
ORDER[1],
ANGLEUNIT["degree",0.0174532925199433]],
AXIS["geodetic longitude (Lon)",east,
ORDER[2],
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4326]]
Data axis to CRS axis mapping: 2,1
Origin = (-36.000000120000003,90.000000290040006)
Pixel Size = (0.001041666670000,-0.001041666670000)
let me know if your files are missing that: we might have to manually set the CRS if it's missing.
The last thing is the version of gdal: I don't think it's a huge problem if VRT_SHARED_SOURCE
isn't set, though it may point to an issue with your gdal installation (it's infamously very hard to install!!!) Could you let me know what version of gdal you're using, and what platform?
gdalinfo --version
# GDAL 3.3.2, released 2021/09/01
Thanks for the thorough answer!
.vrt
file seems to be missing the <SRS>
tag. gdalinfo A1_2020.asc
, the output I get is missing the "Coordinate System is" bit. GDAL 3.0.4, released 2020/01/28
, inside WSL with a Ubuntu 20.04 distribution. I installed it using sudo apt install gdal-bin
, I believe. Thanks for that info!
I think there is a bug in the instructions (I personally converted the files to .tif
first, so mustn't have testet the .asc
instructions).
Could you try this command instead:
gdalbuildvrt -a_srs=epsg:4326 emod2018.vrt ../emod2018/*.asc
Let me know if it works and I can update the instructions!
Seems to have fixed the issue (at least I get an elevation for a given query point)! I ran the command you wrote above, but for me at least, I had to remove the =
in -a_srs=epsg:4326
and replace it with a space. I also used the 2020 dataset.
I've updated the documentation, thanks for helping to improve opentopodata!
Hello,
I'm having some trouble building/using the EMOD dataset. I downloaded the 2020 version of the dataset from the website referenced in the docs, and managed to build a single
.vrt
file and linking it inconfig.yaml
, althoughgdalbuildvrt
doesn't recognize-co
as an option, so I tried to setVRT_SHARED_SOURCE=0
as an environment variable instead (perhaps this is wrong? I'm not that familiar with the gdal toolchain and geospatial data in general, unfortunately). The linking of the dataset inconfig.yaml
seems to work, but when I try to query a location, I get the following error message:I've also tried using the option
-oo
, but that results in the same error.Any pointers here would be greatly appreciated.