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/30038/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 30038,
    "uuid": "44d49866681f4e30b0fd39ec8eeefdaa",
    "title": "Si-SOA: Concentration of elements found in PM2.5 samples taken from the Institute of Atmospheric Physics Beijing site in August 2018 and January 2019",
    "abstract": "This dataset contains both the concentration of PM2.5 in ambient air sampled at a height of 8 metres and the concentration of elements found in the PM2.5 samples resulting from X-ray Fluorescence Spectrometer (XRF) analysis.  The PM2.5 samples were collected in the Institute of Atmospheric Physics, Chinese Academy of Sciences, China in August 2018 and January 2019.  \r\n\r\nThe data was collected to support the study of atmospheric chemistry and processes involving Silicon (Si)  containing fine particles, which potentially contribute to atmospheric pollution. \r\n\r\nThese data were collected as part of the Silicon-containing secondary organic aerosols in ambient air (Si-SOA) Natural Environment Research Council (NERC) funded project.",
    "keywords": "SI-SOA, PM2.5, X-ray, Fluorescence Spectrometer",
    "publicationState": "published",
    "dataPublishedTime": "2020-02-18T09:06:37",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/30040/?format=api",
        "dataPath": "/badc/deposited2020/si-soa/data/x-ray_fluorescence_spectrometer",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 11562,
        "numberOfFiles": 2,
        "fileFormat": "Data are BADC-CSV formatted."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/8156/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/2572/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65473/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65474/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65475/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65476/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65477/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65478/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65479/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65480/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65481/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65482/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65483/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65484/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65485/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65486/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65487/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65488/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65489/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65490/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65491/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65492/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65493/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65494/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65495/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/65496/?format=api"
    ],
    "dataLineage": "Data produced by University of Birmingham and uploaded to Centre for Environmental Data Anaylsis (CEDA) for archiving.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/29996/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/30041/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129796/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129794/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129795/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129800/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129799/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129797/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129793/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129798/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/168416/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129801/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129802/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/129803/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/30039/?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"
        }
    ]
}