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/27454/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 27454,
    "uuid": "6027950b3f214818b661e4e11245b1a8",
    "title": "Hurricane Maria and Dominica: geomorphological change and infrastructure damage baseline surveys: Unmanned Aerial Vehicle (UAV) data processed using Structure from Motion",
    "abstract": "Topographical and orthophotograph data sets created using Structure from Motion (SfM) from Unmanned Aerial Vehicle (UAV) data, presented as Orthophotographs (image and world file),   Digital Surface Models (DSM) (image and world file), and point clouds (LAS format) using EPSG 32620 projection. The data was collected at selected sites on Dominica, Caribbean in January/February 2018 as part of a NERC funded project (NE/RO16968/1) to conduct geomorphological change and infrastructure   damage baseline surveys following hurricane Maria.  The data was flown using either a DJI Phantom 3 or 4, as indicated by the file name.   If the file name includes 'NoGCP' in the file name the data uses the internal GPS and altitude of the DJI UAV. This means the data is not positionally   accurate in absolute terms and should not be used in direct comparison to other georeferenced data.  If the file name includes 'GCP' then the data was georeferenced using ground control derived from UAV data provided by the University of Michigan. This data  is deemed accurate in absolute terms. (World Bank. 2018 Aug 31; Geotechnical Engineering Research Report(UMGE-2018/01))",
    "keywords": "UAV, UAS, hurricane, Structure from Motion, Maria",
    "publicationState": "citable",
    "dataPublishedTime": "2019-04-05T13:44:25",
    "doiPublishedTime": "2019-04-05T14:00:01",
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/27455/?format=api",
        "dataPath": "/badc/deposited2019/dominica_post-maria_UAV/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 143585233877,
        "numberOfFiles": 254,
        "fileFormat": "Data are Jpeg, TIF and LAS formatted."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/7369/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/2397/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data captured using DJI Phantom 3&4 in JPG format, lighting levels balanced in Adobe Lightroom CC Classic, processed using Agisoft PhotoScan 1.4 using version 6.2 of a Python script (https://github.com/gisportsmouth/PhotoScan-Automation-Script)  developed for automatic processing of UAV data. The method involved using an automated gradual selection process. \r\nOutput in EPSG 32620.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/10508/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/27456/?format=api"
    ],
    "observationcollection_set": [],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114783/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114778/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114779/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114780/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114781/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114782/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114784/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114777/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114785/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114786/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114787/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114788/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/27457/?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"
        }
    ]
}