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/31687/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 31687,
    "uuid": "340711b723124764bd42f39c4465d728",
    "title": "NERC-ARF 2014_291 - RG13_06 Flight: Airborne remote sensing measurements",
    "abstract": "Airborne remote sensing measurements collected on 18 October 2014 onboard the Natural Environment Research Council Airborne Research Facility (NERC-ARF) Dornier Do228-101 D-CALM Aircraft for the Biodiversity and Land-use Impacts on Tropical Ecosystem function (BALI) (RG13_06) project (flight reference: 2014_291). This dataset comprises: digital photography data collected using a Leica RCD105 camera, hyperspectral data collected using a Specim Aisa FENIX imager and full-waveform airborne LiDAR data collected using a Leica ALS50II LiDAR.\r\n\r\nData were collected over the  Danum Valley, Malaysia area.",
    "keywords": "RG13_06, RG13/06, aircraft, hyperspectral, remote sensing, lidar",
    "publicationState": "citable",
    "dataPublishedTime": "2020-07-20T16:25:24",
    "doiPublishedTime": "2020-07-21T11:38:09.452720",
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/31688/?format=api",
        "dataPath": "/neodc/arsf/2014/RG13_06/RG13_06-2014_291_Danum_Valley",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 205124951072,
        "numberOfFiles": 1413,
        "fileFormat": "Hyperspectral data are ENVI binary, LiDAR data are LAS and aerial photography are TIF formats"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/8673/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/2674/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data were collected and processed by the NERC-ARF facility and deposited at the Centre for Environmental Data Analysis (CEDA) for archiving.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/10737/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/26485/?format=api"
    ],
    "observationcollection_set": [],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/139908/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/139909/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/139910/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/139911/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/139912/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/139913/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/139915/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/139914/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/31689/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2522/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "registered",
            "accessRoles": null,
            "label": "registered: None group",
            "licenceURL": "http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}