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ARLAS Item Registration Services (AIRS)

ARLAS Item Registration Services offers registration services for Spatio-temporal assets. It manages Items as well as Assets (e.g. raster files, cogs, etc.).

The service exposes the STAC-T methods github.com/stac-api-extensions/transaction as well as a set of methods for handling the assets.

By default, the service manages the assets. When an item is registered, the service checks that the managed asset exists: the asset must be added before the item. Deleting an item is cascaded on the managed assets. An asset can be unmanaged by setting asset.airs:managed=False (or asset.airs__managed=False).

AIRS Data model

The AIRS Model is based on the STAC specifications. It supports the following extensions:

  • view
  • storage
  • eo
  • processing
  • dc3 (ARLAS Datacube Builder)
  • cube
  • sar
  • proj

Also, metadata are enriched by the service and placed in the generated namespace.

Namespaces are prefixes in the key names of the JSON. The : is used for separating the namespace and the field name.

Warning

Since ARLAS does not support the : in field names, the character is replaced by __ for storage and indexation.

For more details, see the AIRS API documentation

Using AIRS

In the following examples, we will:

  • add an asset
  • check that it exists
  • add an item
  • get the item
  • delete the item and its asset

Prerequisites

  • minio
  • elasticsearch
  • docker

See here for the available versions of airs.

Note

The service is deployed on ARLAS_ENDPOINT

Add an asset

curl -X POST \
    "${ARLAS_ENDPOINT}/airs/collections/digitalearth.africa/items/077cb463-1f68-5532-aa8b-8df0b510231a/assets/classification?content_type=image/tiff" \
    -F file=@test/inputs/ESA_WorldCover_10m_2021_v200_N15E000_Map.tif
Result: 
{"msg":"Object has been uploaded to bucket successfully"}

Check that the asset exists

curl -I \
    "${ARLAS_ENDPOINT}/airs/collections/digitalearth.africa/items/077cb463-1f68-5532-aa8b-8df0b510231a/assets/classification"
Result:

HTTP/1.1 204 No Content

Add an item

curl -X POST \
    -H "Content-Type: application/json" \
    "${ARLAS_ENDPOINT}/airs/collections/digitalearth.africa/items" \
    -d @test/inputs/077cb463-1f68-5532-aa8b-8df0b510231a.json

Result: 

{
   "collection":"digitalearth.africa",
   "catalog":"snow",
   "id":"077cb463-1f68-5532-aa8b-8df0b510231a",
   "geometry":{...},
   "bbox": ...,
   "assets":{
      "classification":{...},
      "arlas_eo_item":{...}
   },
   "properties":{
      "datetime":1640908800.0,
      "start_datetime":1609459200.0,
      "end_datetime":1640908800.0,
      "eo:bands":[
         {
            "name":"classification"
         }
      ],
      "proj:epsg":4326,
      "proj:shape":[
         36000.0,
         36000.0
      ],
      "generated:day_of_week":4,
      "generated:day_of_year":365,
      "generated:hour_of_day":1,
      "generated:minute_of_day":60,
      ...
   }
}

Check the item exists

curl -X GET \
    -H "Content-Type: application/json" \
    "${ARLAS_ENDPOINT}/airs/collections/digitalearth.africa/items/077cb463-1f68-5532-aa8b-8df0b510231a"

Result: same as previous call (registration).

Delete the item and its assets

curl -X DELETE \
    -H "Content-Type: application/json" \
    "${ARLAS_ENDPOINT}/airs/collections/digitalearth.africa/items/077cb463-1f68-5532-aa8b-8df0b510231a"