GDAL: use virtual file system (VSI) as datasource in virtual format (VRT files)

What is VRT GDAL?

The VRT driver is a format driver for GDAL that allows a virtual GDAL dataset to be composed from other GDAL datasets with repositioning, and algorithms potentially applied as well as various kinds of metadata altered or added. VRT descriptions of datasets can be saved in an XML format normally given the extension .

What is vsicurl?

/vsicurl/ is a file system handler that allows on-the-fly random reading of files available through HTTP/FTP web protocols, without prior download of the entire file. It requires GDAL to be built against libcurl.

What is VSimEM?

VSimEM is an optimized FDTD solver used for simulating electromagnetic, and electrostatics in complex dielectric and metallic environments. Users of VSimEM can import existing CAD files or build their own unique geometries through the user interface, with numerous options for domain features and boundary conditions.

What is VRT file format?

Driver short name. VRT. OGR Virtual Format is a driver that transforms features read from other drivers based on criteria specified in an XML control file. It is primarily used to derive spatial layers from flat tables with spatial information in attribute columns.

What is the difference between VRT and TIF?

tif files have the same coordinate system (EPSG 29193), but the . vrt file has a User defined projected CRS. The . vrt file was created using Ras Mapper from (HEC-RAS).
 

What is the block size of Geotiff?

The default is 128, or starting with GDAL 3.1 to use the same block size as the full-resolution dataset if possible (i.e. block height and width are equal, a power-of-two, and between 64 and 4096).

What is the tile size of GDAL?

Tiled (512 pixels by default) for imagery, mask and overviews.

What is the purpose of GDAL?

GDAL, also known as GDAL/OGR, is a library of tools used for manipulating geospatial data. GDAL works on both raster and vector data types, and is an incredible useful tool to be familiar with when working with geospatial data.
 

What is a virtual raster?

A virtual raster is a special type of raster whose pixel values are created upon request during data processing or visualization. Its memory footprint includes a reference to a source raster along with details of how the source pixel values will be modified in order to create new pixels.

How to add VRT to QGIS?

To open the VRT in QGIS, click ‘Layer’ in the top menu, ‘Add Layer’, and ‘Add Raster Layer’. Click the 3 dots by ‘Raster Layer’, navigate to your VRT file (either 1. vrt or main_vrt. vrt), and ‘Add’.