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/19987/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 19987,
    "uuid": "7687e5d628f1496cbe6c2622642842b2",
    "title": "ESA Greenland Ice Sheet Climate Change Initiative (Greenland_Ice_Sheet_cci): Ice Velocity Time Series of the Kangerlussuaq Glacier for 2015-2016 from Sentinel-1, v1.0",
    "abstract": "This dataset contains a time series of ice velocity maps for the Kangerlussuag  Glacier in Greenland derived from Sentinel-1 SAR data acquired between January 2015 and June 2016. This dataset has been produced by the ESA Greenland Ice Sheet Climate Change Initiative (CCI) project.\r\n\r\nData files are delivered in NetCDF format at 250m grid spacing in North Polar Stereographic projection (EPSG: 3413). The horizontal velocity components are provided in true meters per day, towards the EASTING(x) and NORTHING(y) directions of the grid.",
    "keywords": "Greenland, Ice sheet, CCI, ESA",
    "publicationState": "published",
    "dataPublishedTime": "2017-01-17T14:56:42",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "superseded",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/26830/?format=api",
        "dataPath": "/neodc/esacci/ice_sheets_greenland/data/greenland_ice_velocity/greenland_iv_250m_s1_kangerlussuaq/v1.0/",
        "oldDataPath": [
            "https://api.catalogue.ceda.ac.uk/api/v2/results/20171/?format=api"
        ],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 49804361,
        "numberOfFiles": 5,
        "fileFormat": "Data files are delivered in NetCDF format at 250m grid spacing in North Polar Stereographic projection (EPSG: 3413). The horizontal velocity components are provided in true meters per day, towards the EASTING(x) and NORTHING(y) directions of the grid."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/5324/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/1650/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/6023/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/12066/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/13230/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/13232/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50547/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/50548/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/53927/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/53928/?format=api"
    ],
    "dataLineage": "Data were processed by the ESA CCI Greenland Ice Sheet project team and supplied to CEDA in the context of the ESA CCI Open Data Portal Project.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/14317/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/14316/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/76006/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/76007/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/79005/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/104954/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/105174/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/105350/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/79003/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/79004/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2553/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/specific_licences/esacci_icesheets_greenland_terms_and_conditions.pdf",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}