# CTG – USGS LULC Composite Theme Grid

Driver short name

CTG

Driver built-in by default

This driver is built-in by default

This driver can read USGS Land Use and Land Cover (LULC) grids encoded in the Character Composite Theme Grid (CTG) format. Each file is reported as a 6-band dataset of type Int32. The meaning of each band is the following one :

1. Land Use and Land Cover Code

2. Political units Code

3. Census county subdivisions and SMSA tracts Code

4. Hydrologic units Code

5. Federal land ownership Code

6. State land ownership Code

Those files are typically named grid_cell.gz, grid_cell1.gz or grid_cell2.gz on the USGS site.

- Land Use and Land Cover Digital Data (Data Users Guide 4) - PDF version from USGS

- Land Use and Land Cover Digital Data (Data Users Guide 4) - HTML version converted by Ben Discoe

- USGS LULC data at 250K and 100K

NOTE: Implemented as `gdal/frmts/ctg/ctgdataset.cpp`.

## Driver capabilities

Supports Georeferencing

This driver supports georeferencing

Supports VirtualIO

This driver supports virtual I/O operations (/vsimem/, etc.)