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/14143/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 14143,
    "uuid": "a26ae5277e3e46d8b8415eae22a4a111",
    "title": "Berlin Stratospheric: 5 to 5 degree horizontal resolution geopotential height and temperature measurements",
    "abstract": "This is a copy of The Berlin Stratospheric Data Series provided to the BADC by K. Labitzke and her collaborators (2002) as a CD from the Meteorological Institute, Free University Berlin. This data set contains temperature and geopotential height data on the 100, 50, 30, 10 mb pressure surfaces on a  5 to 5 degree horizontal resolution, produced at the Meteorological Institute, Free University of Berlin.",
    "keywords": "Berlin Stratospheric, Height, Temperature",
    "publicationState": "published",
    "dataPublishedTime": "2007-02-09T16:37:07",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/14144/?format=api",
        "dataPath": "/badc/CDs/berlin_strat/data/5x5",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 308478710,
        "numberOfFiles": 38735,
        "fileFormat": "Data are ASCII formatted"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/249/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/13/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/25382/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/25388/?format=api"
    ],
    "dataLineage": "This is a copy of The Berlin Stratospheric Data Series, from radiosonde data and rocket observations, provided to the BADC by K. Labitzke and her collaborators (2002) as a CD from the Meteorological Institute, Free University Berlin.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/907/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/54266/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/54267/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/54268/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/54270/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/54271/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/54272/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/54273/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/54269/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": "https://api.catalogue.ceda.ac.uk/api/v2/composites/921/?format=api",
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2521/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/missing_licence.pdf",
            "licenceClassifications": "unstated"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}