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/31848/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 31848,
    "uuid": "5d8221e070e64823891bed7a87840447",
    "title": "FRANC: Doppler radar radial wind observations and associated observation-minus-model residuals from the Met Office UKV 3D Var assimilation scheme",
    "abstract": "The dataset is provided to support the publication 'Diagnosing Observation Error Correlations for Doppler Radar Radial Winds in the Met Office UKV Model Using Observation-Minus-Background and Observation-Minus-Analysis Statistics' by Waller et al (2016). The dataset was created as part of the NERC Flooding from Intense Rainfall (FRANC) project in order to study the observation uncertainties associated with Doppler radar radial wind observations assimilated in to the Met Office UK variable resolution model. The dataset is processed output of the Met Office UKV 3D var assimilation scheme for June, July and August 2013 for four different experimental scenarios. Full details and equations are given in Waller et al (2016) but the four different experimental cases are summarised as follows:\r\n\r\n- Case 1: Control experiment using standard UKV settings in place in January 2014\r\n- Case 2: As Case 1, but with a different background error covariance matrix used in the data assimilation\r\n- Case 3: As Case 1, but with raw Doppler radial wind observations rather than superobservations\r\n- Case 4: As Case 3, but with an improved observation operator.\r\n\r\nFor each case the dataset consists of the radial wind observations assimilated at each assimilation cycle valid between 01/06/2013 and 31/08/2016 along with the associated observation-minus-background and observation-minus-analysis residuals. Each observation also has metadata that describes the location of the observation (both in latitude/longitude co-ordinates, and co-ordinates relative to the radar station) , the assimilation cycle at which it was assimilated and the observation error variance that the observation was assigned in the data assimilation scheme. \r\n\r\nThese data are published under the Open Government License  (http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/) © Crown Copyright, 2020, Met Office”.",
    "keywords": "Doppler radial winds, data assimilation, convection permitting numerical weather prediction",
    "publicationState": "citable",
    "dataPublishedTime": "2020-09-30T10:41:42",
    "doiPublishedTime": "2020-10-05T10:57:05",
    "updateFrequency": "notPlanned",
    "status": "final",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/31849/?format=api",
        "dataPath": "/badc/deposited2020/franc/data/franc_radialwinds/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 239049050,
        "numberOfFiles": 5,
        "fileFormat": "Data are BADC-CSV formatted."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/8730/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/2701/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89700/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89701/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89702/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89703/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89704/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89705/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89706/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89707/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89708/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89709/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89710/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89711/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/89712/?format=api"
    ],
    "dataLineage": "Observation data were quality controlled, superobservations were created and superobservations quality controlled before being assimilated with Met Office UKV background data. The data assimilation output was then prepared for archiving before upload to the Centre for Environmental Data Analysis (CEDA) for long term archiving.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/10753/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/11981/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/31970/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140578/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140570/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140579/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140580/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140581/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140569/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140575/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140576/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140577/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140571/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140572/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140573/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140574/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": "https://api.catalogue.ceda.ac.uk/api/v2/composites/31850/?format=api",
    "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"
        }
    ]
}