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/20092/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 20092,
    "uuid": "81784e3642bd465aa69c7fd40ffe1b1b",
    "title": "EUSTACE / ECA&D:  European land station daily air temperature measurements, homogenised",
    "abstract": "This dataset consists of homogenised time series of daily temperature observations for meteorological stations throughout Europe and the Mediterranean.  The version of the dataset described here is a homogenised version of the ECA&D (European Climate Assessment & Dataset)  daily dataset, produced with funding from the EU Horizon2020 EUSTACE (EU Surface Temperature for All Corners of Earth) project.    \r\n\r\nThe data is available directly from the ECA&D website and is referenced here to form part of the EUSTACE collection of data.   The EUSTACE version of the product is that labelled 'Homogenized ECA Dataset'.   This dataset will continue to be updated by the ECA&D project beyond the end of EUSTACE.\r\n\r\nData is available for non-commercial purposes under the ECA&D terms and conditions (see https://www.ecad.eu//documents/ECAD_datapolicy.pdf).\r\n\r\nTo cite this dataset please use Squintu, AA, van der Schrier, G, Brugnara, Y, Klein Tank, A. \r\nHomogenization of daily temperature series in the European Climate Assessment & Dataset. /Int J Climatol/. 2019; 39: 1243– 1261.  https://doi.org/10.1002/joc.5874\r\n\r\nThe EU EUSTACE project has received funding by the European Union's Horizon 2020 research and innovation programme under grant agreement no 640171.",
    "keywords": "",
    "publicationState": "published",
    "dataPublishedTime": "2019-04-09T16:26:03",
    "doiPublishedTime": null,
    "updateFrequency": "unknown",
    "status": "ongoing",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/27401/?format=api",
        "dataPath": "https://www.ecad.eu/dailydata/predefinedseries.php",
        "oldDataPath": [],
        "storageLocation": "external",
        "storageStatus": "online",
        "volume": 0,
        "numberOfFiles": 0,
        "fileFormat": "ASCII format"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/7354/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/929/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "This data forms part of the  European Climate Assessment & Dataset (ECA&D) (www.ecad.eu)   It has been derived from the non-homogenised version of the ECA&D data.    \r\n\r\nThis dataset has been  produced under funding from the EU EUSTACE project, which has received funding by the European Union's Horizon 2020 research and innovation programme under grant agreement no 640171.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/19556/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/20098/?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/76414/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/76415/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114524/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114526/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114528/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114525/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/204929/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/204930/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114529/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114847/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114848/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": null,
    "procedureComputation": "https://api.catalogue.ceda.ac.uk/api/v2/computations/27402/?format=api",
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2632/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://www.ecad.eu/documents/ECAD_datapolicy.pdf",
            "licenceClassifications": ""
        }
    ],
    "discoveryKeywords": []
}