Get a list of Observation objects.

### Available end points:

- `/observations/` - Will list all Results in the database
- `/observations.json` - Will return all Results in json format. This can
also be achieved by using the accept header. `application/json`
- `/observations/<object_id>/` - Returns Results object with that id

### Available Methods:

- `GET`
- `HEAD`

### Available filters:

- `title`
- `uuid`
- `keywords`
- `status`
- `result_field`
- `discoveryKeywords`
- `updateFrequency`
- `nonGeographicFlag`
- `publicationState`
- `permissions`

### How to use filters:

These filters can be used like django query filters using __ for related model relationships.

- `/observations/?uuid=d594d53df2612bbd89c2e0e770b5c1a0`
- `/observations/?status=completed`
- `/observations/?results_field__dataPath__startswith=/neodc/esacci`
- `/observations/?discoveryKeywords__name=ESACCI`
- `/observations/?nonGeographicFlag=True`

Filters can be stacked to build an 'AND' relationship. E.g.

- `/observations/?publicationState__in=published,citable&nonGeographicFlag=True`
- `/observations/?publicationState__in=published,citable&discoveryKeyword__name=NDGO0003`

GET /api/v2/observations/19114/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 19114,
    "uuid": "59f3a38819e140b49ffe46f32176709e",
    "title": "ESA Aerosol Climate Change Initiative (Aerosol CCI): Level 2 aerosol products from AATSR (SU Algorithm), Version 4.21",
    "abstract": "The ESA Climate Change Initiative Aerosol project has produced a number of global aerosol Essential Climate Variable (ECV) products from a set of European satellite instruments with different characteristics. \r\n\r\nThis dataset comprises the Level 2 aerosol products from AATSR, using the Swansea University (SU) algorithm, version 4.21. \r\n\r\nFor further details about these data products please see the linked documentation.",
    "keywords": "Aerosol, ESA, CCI, AATSR",
    "publicationState": "published",
    "dataPublishedTime": "2016-05-07T12:07:39",
    "doiPublishedTime": null,
    "updateFrequency": "",
    "status": "superseded",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/19115/?format=api",
        "dataPath": "/neodc/esacci/aerosol/data/AATSR_SU/L2/v4.21",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 56694604769,
        "numberOfFiles": 47762,
        "fileFormat": "Data are in NetCDF format"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/3607/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/529/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/25983/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50379/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50380/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50385/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50392/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50393/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50407/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50408/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50409/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50410/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50411/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50412/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50413/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50414/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61900/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61904/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61958/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61959/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61960/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61961/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61962/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61963/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61964/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61965/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61966/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61967/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61968/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61969/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/87635/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89160/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89161/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89162/?format=api"
    ],
    "dataLineage": "Data were processed by the ESA CCI Aerosol project team and supplied to CEDA in the context of the ESA CCI Open Data Portal Project.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/13341/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/13340/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/30128/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71933/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71929/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71931/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/105307/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71928/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/75201/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/104913/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/105129/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71932/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71930/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/13635/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2555/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/specific_licences/esacci_aerosol_terms_and_conditions.pdf",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}