If you've got an existing FlightGear build, there are some additional dependencies:
* GDAL (https://gdal.org/)
** ... which requires PROJ 6 or above (https://proj.org/)
*** ... which requires the sqlite3.11 or above development package (on linux - 'sudo apt-get install libsqlite3-dev')
Note that GDAL and PROJ do not use cmake, so you need to run "./configure" in the source directory before make
VPB is built using cmake e.g.
Choose RASTER data, which will download a geo-referenced TIF image.
== Getting DEM data .