Contrary to man page gdalbuildvrt does not fetch from the last file when there is spatial overlapping about gdal

[jratike80]

Maybe you are testing something else than what you believe, but I cannot directly say what happens. However, I made the most simple test that I could.

Create couple of images with the same geolocation, one with pixel value=100, the other with pixel value=200

gdal_create -of GTiff -ot byte -outsize 100 100 -bands 1 -burn 100 -a_srs epsg:3067 -a_ullr 500000 600000 500500 599500 image1.tif

gdal_create -of GTiff -ot byte -outsize 100 100 -bands 1 -burn 200 -a_srs epsg:3067 -a_ullr 500000 600000 500500 599500 image2.tif

Create couple of vrt files with different image orders

gdalbuildvrt vrttest1.vrt image1.tif image2.tif
gdalbuildvrt vrttest2.vrt image2.tif image1.tif

Now vrttest1.vrt has image2 with value=200 at the bottom, and vrttest2.vrt has image1 with value=100 at the bottom. A test with gdallocationinfo gives expected results:

gdallocationinfo vrttest1.vrt 0 0
Report:
  Location: (0P,0L)
  Band 1:
    <LocationInfo><File>image1.tif</File><File>image2.tif</File></LocationInfo>
    Value: 200

C:\data\000\gdaltest\vrt>gdallocationinfo vrttest2.vrt 0 0
Report:
  Location: (0P,0L)
  Band 1:
    <LocationInfo><File>image2.tif</File><File>image1.tif</File></LocationInfo>
    Value: 100

[jratike80]

Because you have source images with different resolutions you should read this https://gdal.org/programs/gdalbuildvrt.html#cmdoption-gdalbuildvrt-resolution and try

gdalbuildvrt index2.vrt Copernicus_DSM_COG_30_N51_00_E000_00_DEM.tif ALPSMLC30_N051E000_DSM.tif -resolution highest

gdallocationinfo -wgs84 index2.vrt  0 51.4
Report:
  Location: (2P,2161L)
  Band 1:
    <LocationInfo><File>Copernicus_DSM_COG_30_N51_00_E000_00_DEM.tif</File><File>ALPSMLC30_N051E000_DSM.tif</File></LocationInfo>
    Value: 64

Looks correct, but I have never done this before myself.

[dzfranklin]

Thank you.