.. _raster.stacit:

================================================================================
STACIT - Spatio-Temporal Asset Catalog Items
================================================================================

.. versionadded:: 3.4

.. shortname:: STACIT

.. built_in_by_default::

This driver supports opening STAC API ItemCollections, with the input usually being a `STAC API search query <https://github.com/radiantearth/stac-api-spec/tree/main/item-search>`_ or the results saved as a JSON file. Items in the response must include projection information following the `Projection Extension Specification <https://github.com/stac-extensions/projection/>`_.
It builds a virtual mosaic from the items.

A STACIT dataset which has no subdatasets is actually a :ref:`raster.vrt` dataset.
Thus, translating it into VRT will result in a VRT file that directly references the items.

Note that `STAC API ItemCollections <https://github.com/radiantearth/stac-api-spec/blob/main/fragments/itemcollection/README.md>`_ are not the same as  `STAC Collections <https://github.com/radiantearth/stac-spec/tree/master/collection-spec>`_. STAC API ItemCollections are GeoJSON FeatureCollections enhanced with STAC entities.

Open syntax
-----------

STACIT datasets/subdatasets can be accessed with one of the following syntaxes:

* ``filename.json``: local file

* ``STACIT:"https://example.com/filename.json"``: remote file or query

* ``STACIT:"filename.json":asset=my_asset``: specify the name of the asset GDAL should read (i.e. "visual")

* ``STACIT:"filename.json":collection=my_collect,asset=my_asset``: limit to items in a given collection and specify asset to read

* ``STACIT:"filename.json":collection=my_collect,asset=my_asset,crs=my_crs``: specify a collection, asset, and limit to items in a given CRS

Starting with GDAL 3.10, specifying the ``-if STACIT`` option to command line utilities
accepting it, or ``STACIT`` as the only value of the ``papszAllowedDrivers`` of
:cpp:func:`GDALOpenEx`, also forces the driver to recognize the passed
filename or URL.

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

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

-  .. oo:: MAX_ITEMS
      :choices: <integer>
      :default: 1000

      Maximum number of items fetched. 0=unlimited.

-  .. oo:: COLLECTION

      Name of collection to filter items.

-  .. oo:: CRS

      Name of CRS to filter items.

-  .. oo:: ASSET

      Name of asset to read.

-  .. oo:: RESOLUTION
      :choices: AVERAGE, HIGHEST, LOWEST
      :default: AVERAGE

      Strategy to use to determine dataset resolution.

-  .. oo:: OVERLAP_STRATEGY
      :choices: REMOVE_IF_NO_NODATA, USE_ALL, USE_MOST_RECENT
      :default: REMOVE_IF_NO_NODATA
      :since: 3.9.1

      Strategy to use when the ItemCollections contains overlapping items, and
      that some items are fully covered by other items that are more recent.

      Starting with GDAL 3.9.1, the ``REMOVE_IF_NO_NODATA`` strategy is applied
      by default. The STACIT virtual mosaic will omit fully covered items,
      only if no band declares a nodata value.
      (Note that the determination whether a band has a nodata value of not is
      done by opening one of the items, and assuming it is representative of
      the characteristics of the others in the collection).

      This strategy can be forced in all cases by selecting the ``USE_MOST_RECENT``
      strategy (this was the strategy applied prior to 3.9.1)

      The ``USE_ALL`` strategy always causes all items to be listed in the virtual
      mosaic, with the most recent ones being rendered on top of the less recent ones.


Subdatasets
-----------

If a STACIT JSON file contains several collections, assets or CRS,
the driver will return a list of subdataset names to open each of the possible
subdatasets.

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

.. supports_virtualio::

Examples
--------

List the subdatasets associated to a `STAC search <https://github.com/radiantearth/stac-api-spec/tree/master/item-search>`_
on a given collection, bbox and starting from a datetime:

::

    gdalinfo "STACIT:\"https://planetarycomputer.microsoft.com/api/stac/v1/search?collections=naip&bbox=-100,40,-99,41&datetime=2019-01-01T00:00:00Z%2F..\""


Open a subdataset returned by the above request:

::

    gdalinfo "STACIT:\"https://planetarycomputer.microsoft.com/api/stac/v1/search?collections=naip&bbox=-100,40,-99,41&datetime=2019-01-01T00:00:00Z%2F..\":asset=image"


See Also
--------

-  :ref:`raster.stacta` documentation page.
