Overview
A STAC asset is a geospatial feature of a STAC item. For example, bands in an optical image, thumbnails, and metadata files represent different STAC assets.
The cloud-native asset model (CNAM) format transforms an UP42 asset into individual geospatial features available for immediate download. Regardless of provider or delivery format, UP42 transforms assets into a standard model. CNAM also standardizes the following types of files to enable easier integrations:
- Raster data is converted into cloud optimized GeoTIFFS (COGs).
- Vector mask files are converted into GeoJSONs.
Elements of the originally delivered UP42 asset are mapped as individual STAC assets on a STAC item level. Original delivery is mapped as a STAC asset on a STAC collection level.
You can also access CNAM files using the console.
STAC assets in a STAC item
STAC assets are returned as part of a STAC item response body. You can get STAC assets in one of the following ways:
- By requesting a list of all STAC items from a particular STAC collection.
- By requesting a particular STAC item.
- By making a detailed STAC item search request.
{
<...>,
"assets": {
"mgag5ui3_IMG_PHR1A_MS_202208080011285_SEN_6452562101-2_R1C1.JP2": {
"href": "https://api.up42.com/v2/assets/e4a15000-890b-445c-82bb-e4364baac40b",
"title": "Multispectral data",
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": ["data", "multispectral"],
"gsd": 0.7283,
"eo:bands": [
{
"name": "blue",
"common_name": "blue",
"center_wavelength": 0.47,
"full_width_half_max": 0.07
},
{
"name": "green",
"common_name": "green",
"center_wavelength": 0.47,
"full_width_half_max": 0.07
},
{
"name": "red",
"common_name": "red",
"center_wavelength": 0.665,
"full_width_half_max": 0.038
}
]
}
},
<...>
}
Parameter | Overview |
---|---|
href | string The URL of a downloadable or a streamable file related to the STAC asset. |
title | string The STAC asset title. |
type | string The STAC asset media type. |
roles | array of strings The role of the STAC asset. |
gsd | float The ground sample distance, in meters. |
eo:bands | array of objects Electro-optical bands. For more information, see extension specification. |
Parameters of the eo:bands array | |
name | string The name of the band. |
common_name | string The name commonly used to refer to the band to make it easier to search for bands. For more information, see the list of common band names. |
center_wavelength | float The center wavelength of the band, in micrometers. |
full_width_half_max | float Full width at half maximum. The width of the band, as measured at half the maximum transmission, in micrometers. |
Roles
Data
Role | Description |
---|---|
data | A higher-level role for all types of data. The CNAM format transforms all raster assets with the data role into COGs. |
multispectral | An asset related to the multispectral band. |
panchromatic | An asset related to the panchromatic band. |
Metadata
Role | Description |
---|---|
metadata | A higher-level role for all types of metadata. |
bundle | Delivery metadata that contains information about both types of bands, panchromatic and multispectral. |
extended | Detailed metadata for multispectral and panchromatic bands. |
iso-19115 | ISO 19115-1:2014 metadata. |
license | An end-user license agreement (EULA). |
lineage | Processing, ground, or strip lineage. |
lut | A Look-Up-Table with rendering of color curves in a reflectance product. |
quality-elevation | Quality elevation metadata. |
stac | STAC-related metadata. |
stereo | Stereo metadata. |
tile-info | Tiling metadata. |
toa-factors | Top-of-atmosphere reflectance metadata. |
Previews
Role | Description |
---|---|
overview | A preview image of higher resolution than thumbnail . |
thumbnail | A low-resolution preview image, usually up to 600×600 px. |
visual | A full-resolution version of the data, processed for visual use. |
Masks
Role | Description |
---|---|
data-mask | A higher-level role for all types of masks. The CNAM format transforms all vector assets with the data-mask role into GeoJSON files. |
cloud | A cloud mask. |
detector-quality | A quality detector mask. |
footprint | A footprint. |
roi | A region of interest mask. |
saturation | A saturation mask. |
technical-index | A technical index mask. |
visibility | A visibility mask. |
water-detection | A water detection mask. |
Other
Role | Description |
---|---|
index | Spectral indexes. |
rpc | Rational polynomial coefficients. |
Limitations
CNAM is only available for assets added to storage starting in 2023.
Not all geospatial collections are supported. To get a list of supported collections, see Introduction to STAC.