How to extract raster from .gdb instead of empty polygons?

Question

I have met with a problem when importing raster data of light intensity. Concretely, the following file contains raster data of Chinese nightlight intensity. I write the following command to import it:

file_temp = st_read(dsn = 'path/tif.gdb', layer = 'noflare_20131')

light = raster(file_temp)

plot(light)

link for replication data: https://www.dropbox.com/s/o8rn7cnb4a5rc6j/tif.gdb.zip?dl=0

However, it seems that I have only extracted an empty polygon into R without values of light intensity. In contrast, when importing the data into ArcGIS, it could be displayed successfully.

I guess that I should add some options to the command st_read() or raster() while have not figured out a specific solution.

Answer 1

The drivers in GDAL/OGR don't support rasters in FileGDB sources, and you should export from Arc in a different format, such as a GeoTIFF.

Command line tools show no layers for your FileGDB:

$ ogrinfo -al -so tif.gdb/
INFO: Open of `tif.gdb/'
      using driver `OpenFileGDB' successful.
$

So I am slightly surprised that R can read this:

> file_temp = st_read(dsn = './tif.gdb', layer = 'noflare_20131')
Reading layer `noflare_20131' from data source `/home/rowlings/Downloads/tif.gdb' using driver `OpenFileGDB'
Simple feature collection with 1 feature and 3 fields
geometry type:  MULTIPOLYGON
dimension:      XY
bbox:           xmin: 73.3875 ymin: 18.12917 xmax: 134.9875 ymax: 53.50417
geographic CRS: WGS 84

but it appears to be the raster bounds rather than the data itself:

> file_temp
Simple feature collection with 1 feature and 3 fields
geometry type:  MULTIPOLYGON
dimension:      XY
bbox:           xmin: 73.3875 ymin: 18.12917 xmax: 134.9875 ymax: 53.50417
geographic CRS: WGS 84
  RASTER FOOTPRINT_Length FOOTPRINT_Area                      FOOTPRINT
1   <NA>           193.95         2179.1 MULTIPOLYGON (((73.3875 18....

If there are any other vector layers in there, R can't list them and ogrinfo isn't showing them. If there are raster layers, GDAL can't read them.

More info here:

https://stackoverflow.com/questions/27821571/working-with-rasters-in-file-geodatabase-gdb-with-gdal