{"id": "can-nrcan-hrdem-2m", "type": "Collection", "links": [{"rel": "items", "type": "application/geo+json", "href": "https://api.darly.io/collections/can-nrcan-hrdem-2m/items"}, {"rel": "parent", "type": "application/json", "href": "https://api.darly.io/"}, {"rel": "root", "type": "application/json", "href": "https://api.darly.io/"}, {"rel": "self", "type": "application/json", "href": "https://api.darly.io/collections/can-nrcan-hrdem-2m"}, {"rel": "license", "href": "https://open.canada.ca/en/open-government-licence-canada", "title": "Open Government Licence - Canada 2.0"}], "title": "CAN - NRCan HRDEM 2m", "extent": {"spatial": {"bbox": [[-140.96852111816406, 41.67843246459961, -52.61335754394531, 83.2262954711914]]}, "temporal": {"interval": [["2019-10-01T12:00:00+00:00", "2025-11-14T12:00:00+00:00"]]}}, "license": "OGL-Canada-2.0", "keywords": ["DEM", "DTM", "DSM", "elevation", "terrain", "lidar", "photogrammetry", "HRDEM", "NRCan", "Canada", "2m"], "providers": [{"url": "https://natural-resources.canada.ca/maps-tools-publications/satellite-elevation-air-photos/national-elevation-data-strategy", "name": "Natural Resources Canada (NRCan)", "roles": ["producer", "licensor", "host"]}, {"url": "https://darly.io", "name": "Darly", "roles": ["processor"]}], "summaries": {"gsd": [2]}, "description": "High Resolution Digital Elevation Model (HRDEM) Mosaic at 2-meter resolution from Natural Resources Canada (NRCan). Indexed from the `hrdem-mosaic-2m` collection of the NRCan Data Cube STAC API (geo.ca).\n\n**Source & method:** The HRDEM Mosaic merges many acquisition projects into a single continuous surface (newer data replaces older where they overlap). The 2-meter mosaic corresponds to lower-density airborne **lidar** (average nominal pulse density < 2 pts/m\u00b2) and, in northern Canada (north of the productive forest line), to **photogrammetric** DSMs derived from optical stereo satellite imagery (occasionally supplemented by radar interferometry). In the north only a DSM is generally produced, so DTM coverage there may be limited or absent. Hillshades are derived products.\n\n**Products:** DTM (bare earth) and DSM (first surface), plus derived hillshades where available.\n\n**Resolution:** 2 m ground sample distance.\n\n**Coordinate reference:** NAD83(CSRS) / Canada Atlas Lambert (EPSG:3979); orthometric elevations in meters on CGVD2013 (EPSG:6647).\n\n**Documentation:**\n- [Source: NRCan Data Cube STAC API](https://datacube.services.geo.ca/stac/api/) \u2014 collection `hrdem-mosaic-2m`\n- [HRDEM Mosaic dataset record](https://open.canada.ca/data/en/dataset/0fe65119-e96e-4a57-8bfe-9d9245fba06b)\n- [HRDEM Mosaic product specification (PDF)](https://download-telecharger.services.geo.ca/pub/elevation/dem_mne/HRDEMmosaic_mosaiqueMNEHR/HRDEM_Mosaic_Product_Specification.pdf)\n- [NRCan National Elevation Data Strategy](https://natural-resources.canada.ca/maps-tools-publications/satellite-elevation-air-photos/national-elevation-data-strategy)\n", "item_assets": {"dsm": {"type": "image/tiff; application=geotiff; profile=cloud-optimized", "roles": ["data", "dsm"], "title": "Digital Surface Model (DSM)"}, "dtm": {"type": "image/tiff; application=geotiff; profile=cloud-optimized", "roles": ["data", "dtm"], "title": "Digital Terrain Model (DTM)"}, "extent": {"type": "application/geo+json", "roles": ["extent"], "title": "Tile boundary"}, "coverage": {"type": "application/geopackage+sqlite3", "roles": ["metadata"], "title": "Full-resolution data coverage"}, "thumbnail": {"type": "image/png", "roles": ["thumbnail"], "title": "Thumbnail"}, "hillshade-dsm": {"type": "image/tiff; application=geotiff; profile=cloud-optimized", "roles": ["overview"], "title": "Hillshade DSM"}, "hillshade-dtm": {"type": "image/tiff; application=geotiff; profile=cloud-optimized", "roles": ["overview"], "title": "Hillshade DTM"}}, "sci:citation": "Natural Resources Canada, High Resolution Digital Elevation Model (HRDEM) Mosaic - 2 m, https://open.canada.ca/data/en/dataset/0fe65119-e96e-4a57-8bfe-9d9245fba06b.", "stac_version": "1.0.0", "stac_extensions": ["https://stac-extensions.github.io/item-assets/v1.0.0/schema.json", "https://stac-extensions.github.io/scientific/v1.0.0/schema.json"]}