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Version: 2.0-beta

STAC Metadata

All imagery data products are delivered with acquisition time, radiometric, geometric, and other various metadata properties delivered in a JavaScript Object Notation (JSON) format ASCII text file that aligns with the SpatioTemporal Asset Catalog (STAC) open geospatial standard. For more background information please visit the STAC specification website.

Catalog File Contents

The catalog file is a STAC catalog file for a catalog with a single item. The path to that item's STAC JSON file can be located in the list of links. The item has a 'rel' value of 'item' and can be used to locate the items STAC metadata description.

General Information

The following describes general information fields.

Field NameTypeDescription
typestringDescribes the type of item
stac_versionstringSTAC version
idstringSTAC unique identifier
createdstringCreation datetime of this file as ISO 8601 formatted datetime, in UTC (YYYY-MM- DDTHH:MM:SSZ)
updatedstringLast update datetime of this file as ISO 8601 formatted datetime, in UTC (YYYY-MM- DDTHH:MM:SSZ)
stac_extensions[string]List of STAC extensions included in this file

Sensor Information

The following describes the type of sensor used to capture the images.

Field NameTypeDescription
sensor_modestringOperation mode of the sensor
sensor_typestringType of the sensor
product_typestringOutput product

License & Provider

The following describes the license and provider information.

Field NameTypeDescription
licensestringThe type of license. Full license provided in links
providers[Provider Object]Information describing Wyvern as data provider
links[Link Object]List of resource link objects and related URLs
License Link Object
relstringRelationship between the current document and the linked document
hrefstringThe actual link in the format of an URL
titlestringHuman-readable title
Providers Object
namestringName of the organization
roles[string]Roles of the provider
urlstringHomepage of the provider

Satellite Information

The following describes the satellite and constellation that captured the imagery.

Field NameTypeDescription
constellationstringThe name of the constellation
platformstringThe name of the satellite
instruments[string]Name of instrument used
sat:platform_international_designatorstringThe International Designator

Capture Timestamps

The following describes the timestamps of the image capture.

Field NameTypeDescription
datetimestringThe mid-way time of the capture as ISO 8601 formatted datetime, in UTC (YYYY-MM- DDTHH:MM:SSSSSSZ)
start_datetimestringThe start time of the capture as ISO 8601 formatted datetime, in UTC (YYYY-MM- DDTHH:MM:SSSSSSZ)
end_datetimestringThe end time of the capture as ISO 8601 formatted datetime, in UTC (YYYY-MM- DDTHH:MM:SSSSSSZ)

Processing Information

The following describes information about the processing chain.

Field NameTypeDescription
processing:levelstringThe processing level of the delivered data product
processing:facilitystringThe name of the facility that produced the data
processing:versionstringThe version of the primary processing software or processing chain that produced the data

View Geometry Information

The following describes the position of both the satellite and sun during imaging collection.

Field NameTypeDescription
view:off_nadirnumberThe angle from the sensor between nadir (straight down) and the scene centre measured in degrees (0° to 20°)
view:incidence_anglenumberThe incidence angle is the angle between the vertical (normal) to the intercepting surface and the line of sight back to the satellite at the scene centre measured in degrees (0° to 20°)
view:azimuthnumberViewing azimuth angle. The angle measured from the sub-satellite point (point on the ground below the platform) between the scene centre and true north. Measured clockwise from north in degrees (0° to 360°)
view:sun_azimuthnumberSun azimuth angle. From the scene centre point on the ground, this is the angle between truth north and the sun. Measured clockwise in degrees (0° to 360°)
view:sun_elevationnumberSun elevation angle. The angle from the tangent of the scene centre point to the sun. Measured from the horizon in degrees (15° to 90°)

Projection and Geospatial Data

The following describes how to interpret any geospatial data in this file or in the associated Cloud-Optimized GeoTIFF file.

Field NameTypeDescription
gsdnumberGround sample distance measured in metres (m)
geometryGeoJSON Geometry Object of type PolygonThe footprint of the item
bbox[number]Image bounding box in product Coordinate Reference System [xmin, ymin, xmax, ymax]
proj:epsgnumberEPSG code
proj:shape[integer]Number of pixels in Y and X directions for the default grid

Electro-Optical Information

The following describes data that represents a snapshot of the Earth for assets.

Field NameTypeDescription
eo:cloud_covernumberEstimate of cloud cover, in %
eo:bands[Band Object]An array of available bands where each object is a Band Object
Band Object
namestringThe name of the band, as "Band_<centre wavelength in nanometres>nm"
common_namestringThe name commonly used to refer to the band
centre_wavelengthnumberCentre wavelength of the band in micrometres (μm)
full_width_half_maxnumberThe full width at half-maximum (FWHM) for this band in micrometres (μm)
solar_illuminationnumberThe solar illumination for each band which represents the ESUN solar irradiance generated using Thuillier 2003 dataset as measured at half the maximum transmission in units of 'W / (m2 * μm)'

Raster Information

The following describes the included raster assets.

Field NameTypeDescription
raster:bands[Raster Band Object]An array of available bands where each object is a [Band Object]
Raster Band Object
nodatanumberPixel values used to identify pixels that are nodata in the band
samplingstringIndicates whether a pixel value should be assumed to represent a sampling over the region of the pixel or a point sample at the centre of the pixel
data_typestringThe data type of the pixels in the band
unitstringUnit denomination of the pixel value
scalenumberMultiplicator factor of the pixel value to transform into the value. Used for hyperspectral files only.
offsetnumberNumber to be added to the pixel value (after scaling) to transform into the value. Used for hyperspectral files only.
classification:classes[Classification Class Object]An array of available classes where each object is a [Class Object]
Class Object
valueintegerValue of the class
namestringShort name of the class for machine readability
titlestringHuman-readable name for use in, e.g. a map legend
descriptionstringDescription of the class
nodatabooleanIf set to true classifies a value as a no-data value. Only present in the nodata class object

Wyvern-Specific Information

The following describes the information specific to Wyvern data.

Field NameTypeDescription
wyvern:radiometric_resolutionnumberThe radiometric resolution of the image, specified in bits

Asset File Information

The following describes the asset file information.

Field NameTypeDescription
hrefstringURI to the asset object
typestringMedia type of the asset
titlestringThe asset title
descriptionstringA description of the asset
file:checksumstringFile checksum
file:sizeintegerThe file size, specified in bytes
roles[string]The semantic roles of the asset