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/27179/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 27179,
    "uuid": "d9aaa1c2371147669e4ace0446dd9758",
    "title": "BAS Twin-Otter flight 218 MAC flight: Airborne atmospheric measurements from core and non-core instrument suites on board the BAS Masin Twin-Otter aircraft.",
    "abstract": "Airborne atmospheric measurements from core and non-core instrument suites data on board the British Antarctic Survey (BAS) Masin Twin-Otter aircraft collected for the Microphysics of Antarctic Clouds (MAC) project.",
    "keywords": "MAC, BAS, airborne, atmospheric measurements",
    "publicationState": "published",
    "dataPublishedTime": "2020-07-23T11:01:26",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/27189/?format=api",
        "dataPath": "/badc/mac/data/twinotter/flight218_20151127",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 175559819,
        "numberOfFiles": 2,
        "fileFormat": "NetCDF"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/7304/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/2362/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51090/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51105/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51106/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51107/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51108/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51110/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51112/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51113/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51114/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51115/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51117/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51118/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51119/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51120/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/59259/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/59260/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/59261/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/59262/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/59263/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/59264/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/59265/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/59266/?format=api"
    ],
    "dataLineage": "Data were collected by instrument scientists during the flight before preparation and delivery for archiving at the Centre for Environmental Data Analysis (CEDA).",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/19273/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/19274/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/7571/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113820/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113819/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113821/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113822/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113823/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113824/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113825/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113818/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113826/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113827/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/27180/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2522/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "registered",
            "accessRoles": null,
            "label": "registered: None group",
            "licenceURL": "http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}