# S111 -- S-111 Surface Currents Product

Driver short name

S111

Build dependencies

libhdf5

New in version 3.9.

This driver provides read-only support for surface currents in the S-111 format, which is a specific product profile in an HDF5 file.

S-111 files have two image bands representing the following values for each cell in a raster grid area:

- surface current speed (band 1), in knots

- surface current direction (band 2), in degree measured from true north clock-wise.

When opening a S-111 file, no raster band is directly available. But a list of subdatasets will be reported, one for each timestamp available in the file.

An actual dataset can be opened through such a subdataset, with a syntax like `S111:"filename.h5":Group_001`.

Georeferencing is reported.

Note that the driver currently only supports regularly gridded S111 datasets.

## Driver capabilities

Supports Georeferencing

This driver supports georeferencing

Supports VirtualIO

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

## Open options

- NORTH_UP=[YES/NO]: Defaults to `YES`. Whether the top line of the dataset should be the northern-most one.

  This is the default behavior of most GDAL formats, but the native organization of the data in S-111 products is to have the first line of the grid being the southern-most one. This native organization can be exposed by the driver by setting this option to NO (in which case the 6th term of the geotransform matrix will be positive)

## See Also

- Implemented as s111dataset.cpp.

- S-111 Bathymetric Surface Product Specification

- BAG driver

- S-102 driver

- S-104 driver