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/4034/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 4034,
    "uuid": "140c1b08cad8e2f080ae9b7b89f00fab",
    "title": "UTLS THESEO: Balloon-borne Near-IR laser spectrometer atmospheric methane measurements from Kiruna station, Sweden",
    "abstract": "Extension of the Third European Stratospheric Experiment on Ozone (THESEO) balloon-borne measurements of atmospheric tracers and chemically active gases in the mid-latitude lower stratosphere for tests of atmospheric transport UTLS Round 1 project led by Dr R.L.Jones, Dr J.A.Pyle and Dr Neil Harris, Centre for Atmospheric Sciences, University of Cambridge and P.T. Woods, National Physical Laboratory (NPL). \r\n\r\nThis dataset contains atmospheric methane measurements from a balloon-borne near-IR laser spectrometer.\r\n\r\nThe data shows the methane mixing ratio at different atmospheric pressures. The overall scientific objective within this proposal was to contribute to the understanding of middle latitude ozone loss by making measurements of a number of important tracers of atmospheric motion and photochemistry, and by interpreting these measurements with state-of-the-art models of atmospheric chemistry and transport.\r\n",
    "keywords": "UTLS, THESEO, balloon, chemistry",
    "publicationState": "published",
    "dataPublishedTime": "2007-03-13T15:32:42",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/4035/?format=api",
        "dataPath": "/badc/utls/data/theseo/npl",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 70637,
        "numberOfFiles": 7,
        "fileFormat": "Data are NASA Ames formatted"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/1149/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/779/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/25398/?format=api"
    ],
    "dataLineage": "Data collected by balloon-borne near-infra-red tunable diode laser spectrometer from the National Physical Laboratory (NPL), launched from Kiruna during the 1999/2000 winter, then interpreted using 3D chemical transport models already developed at Cambridge.\r\nData files were provided as is in 2000 to the BADC for archiving.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/2767/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/14405/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/4033/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/19632/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/19634/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/19635/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/19636/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/19637/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/55933/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/19629/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/19631/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/55934/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/55935/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/55936/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/55937/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/4037/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2526/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}