.. _raster.s102:

================================================================================
S102 -- S-102 Bathymetric Surface Product
================================================================================

.. shortname:: S102

.. build_dependencies:: libhdf5

.. versionadded:: 3.8

This driver provides read-only support for bathymetry data in the S-102 format,
which is a specific product profile in an HDF5 file.

S-102 files have two image bands representing depth (band 1),
uncertainty (band 2) values for each cell in a raster grid area.

Note that positive values of depth mean values *below* the reference surface
of the vertical datum. The :oo:`DEPTH_OR_ELEVATION` open option can be set
to ``ELEVATION`` to expose depth values as elevation values, by negating their sign
(i.e. positive values of elevation mean values above the reference surface)

Georeferencing is reported.

Nodata, minimum and maximum values for each band are also reported.

Supported versions of the specification are S-102 v2.1, v2.2 and v3.0
(support for v3.0 spatial metadata added in GDAL 3.10. Multiple grids per
file, as permitted by S-102 v3.0, are not supported currently. Only the
first one will be reported.)

Driver capabilities
-------------------

.. supports_georeferencing::

.. supports_virtualio::

Open options
------------

|about-open-options|
The following open options are supported:

- .. oo:: DEPTH_OR_ELEVATION
     :choices: DEPTH, ELEVATION
     :default: DEPTH

     Whether to report depth or elevation.
     Positive values of depth mean values *below* the reference surface of the
     vertical datum.
     Positive values of elevation mean values *above* the reference surface of the
     vertical datum (which is the convention used by the :ref:`BAG driver <raster.bag>`)

- .. oo:: NORTH_UP
     :choices: YES, NO
     :default: 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-102 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)

Spatial metadata support
------------------------

Starting with GDAL 3.9, GDAL can handle QualityOfSurvey
(or QualityOfBathymetryCoverage in S102 v3.0) spatial metadata.

When such spatial metadata is present, the subdataset list will include
a name of the form ``S102:"{filename}":QualityOfSurvey`` (
or ``S102:"{filename}":QualityOfBathymetryCoverage`` in S102 v3.0)

The ``/QualityOfSurvey/featureAttributeTable``
(``/QualityOfBathymetryCoverage/featureAttributeTable`` in S102 v3.0)
dataset is exposed as a
GDAL Raster Attribute Table associated to the GDAL raster band. The pixel
values of the raster match the ``id`` column of the Raster Attribute Table.

See Also
--------

-  Implemented as :source_file:`frmts/hdf5/s102dataset.cpp`.
-  `S-102 Bathymetric Surface Product Specification <https://registry.iho.int/productspec/view.do?idx=199&product_ID=S-102&statusS=5&domainS=20&category=product_ID&searchValue=>`__
-  :ref:`BAG driver <raster.bag>`
-  :ref:`S-104 driver <raster.s104>`
-  :ref:`S-111 driver <raster.s111>`
