Archive Catalog Image Footprint File Download

Overview

In addition to searching for individual Capella SAR data collects, you can also use the catalog service to search for and download geospatial files of the image footprints in the Capella public archive. This data is provided in bulk for the entire Capella archive for exploration and analysis in third-party geospatial tools and applications.

Search for Archive Catalog Image Footprint Files

The archive catalog image footprint files available for download are available through the following request:

GET https://api.capellaspace.com/catalog/archive-export/available

which returns a response similar to the following:

{
    "latest": [
        "capella_archive_export_latest.geoparquet",
        "capella_archive_export_latest.gpkg",
        "capella_archive_export_latest.shp.zip"
    ],
    "weekly": [
        "2020/43/capella_archive_export_20201019_20201026.geoparquet",
        "2020/43/capella_archive_export_20201019_20201026.gpkg",
        "2020/43/capella_archive_export_20201019_20201026.shp.zip",
        "2020/44/capella_archive_export_20201026_20201102.geoparquet",
        "2020/44/capella_archive_export_20201026_20201102.gpkg",
        "2020/44/capella_archive_export_20201026_20201102.shp.zip",
        "2020/45/capella_archive_export_20201102_20201109.geoparquet",
        "2020/45/capella_archive_export_20201102_20201109.gpkg",
        "2020/45/capella_archive_export_20201102_20201109.shp.zip",
        ...
        ... truncated for brevity
        ...
        "2023/35/capella_archive_export_20230828_20230904.geoparquet",
        "2023/35/capella_archive_export_20230828_20230904.gpkg",
        "2023/35/capella_archive_export_20230828_20230904.shp.zip",
        "2023/36/capella_archive_export_20230904_20230911.geoparquet",
        "2023/36/capella_archive_export_20230904_20230911.gpkg",
        "2023/36/capella_archive_export_20230904_20230911.shp.zip",
        "2023/37/capella_archive_export_20230911_20230918.geoparquet",
        "2023/37/capella_archive_export_20230911_20230918.gpkg",
        "2023/37/capella_archive_export_20230911_20230918.shp.zip"
    ],
    "full": [
        "capella_archive_export_full.geoparquet",
        "capella_archive_export_full.gpkg",
        "capella_archive_export_full.shp.zip"
    ]
}

All archive catalog image footrpint files available for download are organized into three timescale groupings:

latest
- All collects captured in latest 7-day rolling period
- Updated daily at 10:00 UTC
weekly
- All collects broken out by week of capture (Monday – Sunday) and listed chronologically
- Latest 4 weeks are updated daily at 10:00 UTC (to account for new data that may enter the public archive from archive holdback)
full
- All collects in the public archive
- Updated weekly, Mondays at 10:00 UTC

And are provided in the following industry standard geospatial data formats:

GeoParquet
- Apache Parquet is a powerful column-oriented data format, built from the ground up as a modern alternative to CSV files. GeoParquet is an incubating Open Geospatial Consortium (OGC) standard that adds interoperable geospatial types (Point, Line, Polygon)
GeoPackage
- An open, standards-based, platform-independent, portable, self-describing, compact format for transferring geospatial information
Shapefile (in a compressed zip file)
- Esri vector data storage format for storing the location, shape, and attributes of geographic features

Download Archive Catalog Image Footprint Files

The archive catalog image footrpint files can be downloaded through a POST request with a properly formed message body to:

POST https://api.capellaspace.com/catalog/archive-export/presigned

The message body can include three parameters:

exportType
- Values:
  - latest
  - weekly
  - full
- Required
exportFormat
- Values:
  - geoparquet
  - gpkg
  - shp.zip
- Optional
  - Not to be included if fileNames is specified
  - Must be included if fileNames is NOT specified
fileNames
- List of specific file name(s) to download
- Optional
  - Not to be included if exportFormat is specified
  - Must be included if exportFormat is NOT specified

Message body examples

Signed URL for latest data file in GeoPackage format:

POST https://api.capellaspace.com/catalog/archive-export/presigned
  {
      "exportType": "latest",
      "exportFormat": "gpkg"
  }

Signed URLs for all weekly files in GeoParquet format:

POST https://api.capellaspace.com/catalog/archive-export/presigned
  {
      "exportType": "weekly",
      "exportFormat": "geoparquet"
  }

Signed URL for full data file in Shapefile format:

POST https://api.capellaspace.com/catalog/archive-export/presigned
  {
      "exportType": "full",
      "exportFormat": "shp.zip"
  }

Signed URL for a specific weekly file in GeoPackage format:

POST https://api.capellaspace.com/catalog/archive-export/presigned
  {
      "exportType": "weekly",
      "fileNames": ["2023/37/capella_archive_export_20230911_20230918.gpkg"]
  }

Response example (truncated)

[
        {
            "exportType": "weekly",
            "exportFile": "2023/37/capella_archive_export_20230911_20230918.gpkg",
            "downloadHref": "https://capella-archive-export-prod.s3.amazonaws.com/weekly/2023/37/capella_archive_export_20230911_20230918.gpkg?AWSAccessKeyId..."
        }
    ]

Response properties

exportType
- The type of export, which describes the export timescale grouping
- Values
  - latest
  - weekly
  - full
exportFile
- The name of the file to be downloaded
downloadHref
- The signed URL to download the file
- The URL is valid for 1 hour after generation

File content

All archive catalog image footprint files contain the following information for each collect included in the export:

Collect footprint geometry
Collect metadata
- id
  - Capella unique Collect ID
- datetime
  - Datetime the collect was acquired
- mode
  - Imaging mode of the collect
- products
  - List of image formats available for the collect
- url
  - Link to view the collect in the Capella Console UI
- look_angle
  - Look angle - the angle between the sub-satellite point and the image center point
- incd_angle
  - Incidence angle - the angle between the radar beam and the normal to the surface of the earth
- sqnt_angle
  - Squint angle used for image collection
- num_looks
  - Number of looks used for multi-look processing
- observ_dir
  - Observation direction - whether the spacecraft is looking left or right with respect to its velocity during image acquisition
- orbt_state
  - Orbit state - whether the spacecraft is on the ascending (south to north) or descending (north to south) orbit during image acquisition
- orbt_plane
  - Orbital plane of the satellite used during image acquisition
- polariztn
  - Imaging polarization used in image acquisition
- SLC
  - STAC ID (unique name) of the SLC format for the collect (if available)
- GEO
  - STAC ID (unique name) of the GEO format for the collect (if available)
- GEC
  - STAC ID (unique name) of the GEC format for the collect (if available)
- SICD
  - STAC ID (unique name) of the SICD format for the collect (if available)
- SIDD
  - STAC ID (unique name) of the SIDD format for the collect (if available)
- CPHD
  - STAC ID (unique name) of the CPHD format for the collect (if available)

Additional Information

For more information on searching for and downloading archive imagery footprint files, see the API reference for the Catalog Service.