Build VRT from list of VRTs in Python

Question

I have a list with lots of VRTs. Each VRT is the mosaic for a single band for a single band. What I want to do is to make a final TIFF with as many layers as bands. I'm trying to first make one VRT and then convert it to a TIFF in Python. But what I get is a TIFF with a single layer...

My list of VRTs (vrts_per_date) kind of looks like this:

[296B02.vrt', 296B10.vrt', 296B08.vrt', 296B12.vrt', 296B07.vrt', 296B03.vrt', 296B11.vrt'...]

And then I use:

single_vrt = gdal.BuildVRT("my.vrt" vrts_per_date)

And finally I want to make a TIFF with all bands, so I use:

final_tif = gdal.Translate("my.tiff", single_vrt)

But when I open it in QGIS it's a mosaic, but with just one band... How can I get a TIFF as output with as many bands as VRTs in vrts_per_date?

Answer 1

By default BuildVRT creates a mosaic:

>>> verts_per_date = ['out1.vrt','out2.vrt','out3.vrt']
>>> mosaic_vrt = gdal.BuildVRT("my.vrt", verts_per_date)
>>> mosaic_tif = gdal.Translate("mymosaic.tiff", mosaic_vrt)

That creates mymosaic.tiff as a single band.

To create a multi-band VRT, pass separate=True:

>>> verts_per_date = ['out1.vrt','out2.vrt','out3.vrt']
>>> layer_vrt = gdal.BuildVRT("mylayer.vrt", verts_per_date, separate=True)
>>> layer_tif = gdal.Translate("mylayer.tiff", layer_vrt)

that creates mylayer.tiff with three bands.

Read the help for help(gdal.BuildVRTOptions) for more help, this is mentioned in help(gdal.BuildVRT).

  targetAlignedPixels --- whether to force output bounds to be multiple of output resolution.
  separate --- whether each source file goes into a separate stacked band in the VRT band.
  bandList --- array of band numbers (index start at 1).

Note there are some typos in your code and I had to create three VRTs to test this. Please try and make reproducible examples!