Exercise 7 - Environmental data via OGC - Environmental Data Retrieval
OGC API - Environmental Data Retrieval provides a Web API to access environmental data using well defined query patterns:
OGC API - Environmental Data Retrieval uses OGC API - Features as a building block, thus enabling streamlined integration for clients and users. EDR can be considered a convenience API which does not require in depth knowledge about the underlying data store/model.
pygeoapi support
pygeoapi supports the OGC API - Environmental Data Retrieval specification by leveraging both feature and coverage provider plugins.
Note
See the official documentation for more information on supported EDR backends
Publish environmental data in pygeoapi
Let's try publishing some ICOADS data via the EDR xarray plugin. The sample ICOADS data can be found in workshop/exercises/data/coads_sst.nc
:
Update the pygeoapi configuration
Open the pygeoapi configuration file in a text editor. Add a new dataset section as follows:
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Save the configuration and restart Docker Compose. Navigate to http://localhost:5000/collections
to evaluate whether the new dataset has been published.
At first glance, the icoads-sst
collection appears as a normal OGC API - Coverages collection. Let's look a bit closer at the colleciton description:
Client access
Currently there is no support for EDR in common tooling. The example below provides a generic workflow using the Python requests library:
>>> import requests
>>> collection = requests.get('http://localhost:5000/collections/icoads-sst').json()
>>> collection['id']
'icoads-sst'
>>> collection['title']
'International Comprehensive Ocean-Atmosphere Data Set (ICOADS)'
>>> collection['description']
'International Comprehensive Ocean-Atmosphere Data Set (ICOADS)'
>>> collection['parameter-names'].keys()
dict_keys(['SST', 'AIRT', 'UWND', 'VWND'])
>>> params = {'coords': 'POINT(-28 14)', 'parameter-name': 'SST'}
>>> position_query = requests.get('http://localhost:5000/collections/icoads-sst/position', params=params).json()
>>> position_query['ranges']['SST']['values']
[26.755414962768555, 26.303892135620117, 26.512916564941406, 26.799564361572266, 27.48826026916504, 28.04759979248047, 28.745832443237305, 28.5635986328125, 28.272104263305664, 28.526521682739258, 28.25160026550293, 27.074399948120117]
Summary
Congratulations! You are now able to publish environmental data to pygeoapi.