readers.stac

Spatio Temporal Access Catalog (STAC) is a common language to describe geospatial information, so it can more easily be worked with, indexed, and discovered. The STAC reader will read Catalogs and Features. For Catalogs, the reader will iterate through items available in the Links key, creating a list of reads to accomplish.

Default Embedded Stage

This stage is enabled by default

Example

[
    {
        "type": "readers.stac",
        "filename": "https://s3-us-west-2.amazonaws.com/usgs-lidar-stac/ept/catalog.json",
        "reader_args": [{"type": "readers.ept", "resolution": 100}],
        "items": ["MD_GoldenBeach_2012"],
        "catalogs": ["3dep"],
        "properties": { "pc:type": ["lidar", "sonar"], "pc:encoding": "ept" },
        "asset_name": "ept.json",
        "date_ranges": [
            [
                "2022-11-11T0:00:0Z",
                "2022-11-30T0:00:0Z"
            ]
        ],
        "validate_schema": true
    }
]

pdal info --input https://s3-us-west-2.amazonaws.com/usgs-lidar-stac/ept/MD_GoldenBeach_2012.json \
    --driver readers.stac --asset_name ept.json --summary

Options

filename

STAC endpoint, local or remote, that corresponds to a Catalog, Feature or ItemCollection.

asset_names

The list of asset names that should be looked at to find the source data. The default is ‘data’.

date_ranges

A list of date ranges to prune Features by. Example: --readers.stac.date_ranges '[["2022-11-11T0:00:0Z","2022-11-30T0:00:0Z"],...]'

bounds

Bounds to prune Features by. Form: ([minx,maxx],[miny,maxy],[minz,maxz]) Example: --readers.stac.bounds '([-79.0,-74.0],[38.0,39.0])'

items

List of Regular Expression strings to prune STAC Item IDs by. Example: --readers.stac.items '["MD_GoldenBeach_2012", "USGS_LPC\\w{0,}"]'

catalogs

List of Regular Expression strings to prune STAC Catalog IDs by. Root catalog IDs are always included in the list. Example: --readers.stac.catalogs '["3dep-test", "USGS"]'

collections

List of Regular Expression strings to prune STAC Collection IDs by. This will filter by the collections key in a STAC Item and the id key of the STAC Collection. Example: --readers.stac.collections '["3dep-test", "USGS"]'

validate_schema

Boolean value determining if the reader should validate the supplied STAC as it’s being read using JSON schema and the publicly available STAC schemas and list of STAC extension schemas.

properties

A key value mapping (JSON) of properties and the desired values to prune Features by. Different keys will be AND’d together, and list of values will OR’d together. Example: --readers.stac.properties '{"pc:type":["lidar","sonar"],"pc:encoding":"ept"}' In this example, a Feature must have a pc:type key with values of either lidar or sonar, and a pc:encoding key with a value of ept.

reader_args

A list of JSON objects with keys of reader options and the values to pass through. These will be in the exact same form as a Pipeline Stage object minus the filename.

Exmaple:

--readers.stac.reader_args \
'[{"type": "readers.ept", "resolution": 100}, {"type": "readers.las", "nosrs": true}]'

catalog_schema_url: URL of JSON schema you’d like to use for JSON schema validation of STAC Catalogs.
collection_schema_url: URL of JSON schema you’d like to use for JSON schema validation of STAC Collections.
feature_schema_url: URL of JSON schema you’d like to use for JSON schema validation of STAC Items/Features.

Metadata

Metadata outputs will include ids and item_ids for representings STAC Feature Ids, as well as catalog_ids and collection_ids representing STAC Catalogs and Collections, respectively.

pdal info --summary --driver readers.stac \
--readers.stac.asset_names 'ept.json' \
--readers.stac.asset_names 'data' \
${PDAL_DIR}/test/data/stac/local_catalog/catalog.json

{
    "file_size": 1177,
    "filename": "/PDAL_DIR/test/data/stac/local_catalog/catalog.json",
    "now": "2023-08-07T15:48:59-0500",
    "pdal_version": "2.6.0 (git-version: 54be24)",
    "reader": "readers.stac",
    "summary":
    {
        "bounds":
        {
            "maxx": 637179.22,
            "maxy": 5740737,
            "maxz": 1069,
            "minx": -10543360,
            "miny": 848935.2,
            "minz": -22
        },
        "dimensions": "ClassFlags, Classification, EdgeOfFlightLine, GpsTime, Intensity, NumberOfReturns, PointSourceId, ReturnNumber, ScanAngleRank, ScanChannel, ScanDirectionFlag, UserData, X, Y, Z, OriginId, Red, Green, Blue",
        "metadata":
        {
            "catalog_ids":
            [
                "3dep"
            ],
            "collection_ids":
            [
                "usgs-test"
            ],
            "ids":
            [
                "IA_SouthCentral_1_2020",
                "MI_Charlevoix_Islands_TL_2018",
                "MD_GoldenBeach_2012",
                "Autzen Trim"
            ],
            "item_ids":
            [
                "IA_SouthCentral_1_2020",
                "MI_Charlevoix_Islands_TL_2018",
                "MD_GoldenBeach_2012",
                "Autzen Trim"
            ]
        },
        "num_points": 44851411750
    }
}

Curl Timeouts

STAC reader, and PDAL as a whole, rely on curl for external requests. The curl requests default to a timeout of 5s. If your requests are failing, it could be because the timeout is too short. You can set CURL_TIMEOUT in your environment to get around this.

To debug your requests to make sure that the timeout is the problem, set VERBOSE=1 in your environment before running your PDAL task.

VERBOSE=1 CURL_TIMEOUT=30 \
    pdal info --summary --driver readers.stac \
    --readers.stac.asset_names 'ept.json' \
    --readers.stac.asset_names 'data' \
    ${PDAL_DIR}/test/data/stac/local_catalog/catalog.json