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/5779/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 5779,
    "uuid": "c51faade69520b1838b90bad689ec83c",
    "title": "Hameldon Hill C-band rain radar 1 km rainfall rate data",
    "abstract": "1 km resolution data from the NIMROD system data describe rain-rate observations taken at Hameldon, Lancashire, by NIMROD, which is a very short range forecasting system used by the Met Office. 1 km rain rate data are available from 2011 until present. Radar images from the C-band (5.3 cm wavelength) radar are received by the Nimrod system 5 minute intervals.",
    "keywords": "Met Office, NIMROD, rain radar",
    "publicationState": "published",
    "dataPublishedTime": "2011-02-23T00:00:00",
    "doiPublishedTime": null,
    "updateFrequency": "continual",
    "status": "ongoing",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/5780/?format=api",
        "dataPath": "/badc/ukmo-nimrod/data/single-site/hameldon-hill/1km/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 1686016978,
        "numberOfFiles": 2286,
        "fileFormat": "NIMROD product data are in the non-standard NIMROD binary format. Refer to linked documentation for further details."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/3281/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/127/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/25899/?format=api"
    ],
    "dataLineage": "Data are acquired from rain radar network in the UK and Europe by the Met Office's NIMROD system. Composite products (images and data) and single site data are then sent to the BADC by the Met Office's DART operational dissemination system. Raw polar data from single sites are sent through from the RADARNET team at the Met Office. On arrival at the BADC the data are ingested after a one day quarantine.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/3777/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/5736/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/5709/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/24801/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/24804/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/24805/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/24807/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/43653/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/43654/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/24803/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/24802/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/5781/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2532/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "restricted",
            "accessRoles": "ukmo_wx",
            "label": "restricted: ukmo_wx group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/specific_licences/ukmo_agreement.pdf",
            "licenceClassifications": "academic"
        },
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2533/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "restricted",
            "accessRoles": "ukmo_wx_gov",
            "label": "restricted: ukmo_wx_gov group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/specific_licences/ukmo_agreement_gov.pdf",
            "licenceClassifications": "policy"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}