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/27438/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 27438,
    "uuid": "e838a628dacc438ab4749b011ae7225f",
    "title": "South Asian Monsoon: whole air sample halocarbon measurements onboard FAAM aircraft flights",
    "abstract": "This dataset contains halocarbon measurements made from whole air samples collected on board the FAAM (Facility for Airborne Atmospheric Measurements) aircraft during the NERC (National Environmental Research Council) South West Asian Aerosol Monsoon Interactions (SWAAMI) project and the Interaction of Convective Organization and Monsoon Precipitation, Atmosphere, Surface and Sea (INCOMPASS) project - both of which were funded under the 'Drivers of Variability in the South Asian Monsoon' programme.\r\nWhole air samples were collected in 3 L stainless steel cylinders (WAS flasks) aboard the FAAM aircraft during 11 flights (b957, b959, b963, b966, b968, b969, b971, b972, b974, b975, b976). In total, 176 samples were collected above India and the Indian Ocean, from the 12th June - 10th July 2016. Samples were returned to the University of Bristol for analysis by Medusa Gas Chromatography Mass Spectrometry, resulting in concentration (mole fraction) data for chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and chlorocarbons (e.g. dichloromethane). Each sample was analysed three times in total, with the reported mole fraction taken to be the average of these three analyses. Samples were collected by Daniel Say, with significant input from Anita Ganesan (flight planning) and Simon O'Doherty (interpretation of measurements).",
    "keywords": "b957, b959, b963, b966, b968, b969, b971, b972, b974, b975, b976, halocarbons, HCFC, HFC, FAAM, SWAAMI, INCOMPASS, whole air sample, WAS",
    "publicationState": "published",
    "dataPublishedTime": "2019-03-28T16:07:36",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/27439/?format=api",
        "dataPath": "/badc/sa-monsoon/data/swaami/bristol-gcms/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 444306,
        "numberOfFiles": 20,
        "fileFormat": "Data are NetCDF formatted."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/7364/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/2395/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51156/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51157/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/51158/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/61969/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/68171/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/68172/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/68173/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/68174/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/68175/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/68176/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/68177/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/68178/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/68179/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90446/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90447/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90448/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90449/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90450/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90451/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90452/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90453/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90454/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/90455/?format=api"
    ],
    "dataLineage": "Flask samples were collected by Daniel Say on board the Facility for Airborne Atmospheric Measurements (FAAM) aircraft. Samples were analysed using a Medusa Gas Chromatography Mass Spectrometry instrument at the University of Bristol. Data were deposited at the Centre for Environmental Data Analysis (CEDA) for archiving.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/19201/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/19202/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/27440/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/20240/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/20235/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114694/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114689/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114690/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114691/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114692/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114693/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114695/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114688/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114696/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114697/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/27441/?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"
        }
    ]
}