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/6312/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 6312,
    "uuid": "cae68b35c821ce036f28eda09e7d3a7c",
    "title": "ECMWF ERA-Interim: reduced N256 Gaussian gridded pressure level analysis time parameter data (ggap)",
    "abstract": "Pressure level analysis time parameters on a reduced N256 Gaussian grid from the European Centre for Medium-Range Weather Forecasts (ECWMF) ERA-Interim programme.\r\n\r\nThe ERA-Interim global atmospheric reanalysis of the covers 1979 to August 2019. This follows on from the ERA-15 and ERA-40 re-analysis projects\r\n\r\nThis subset of the ERA-Interim dataset contains 16 parameters on 37 pressure levels.",
    "keywords": "ECMWF, ERA, ERA, Interim, reanalysis, surface, model, Gaussian, N256, analysis, pressure level",
    "publicationState": "published",
    "dataPublishedTime": "2014-08-26T15:11:19",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/6313/?format=api",
        "dataPath": "/badc/ecmwf-era-interim/data/gg/ap",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 18440841745115,
        "numberOfFiles": 59416,
        "fileFormat": "Data are netCDF formatted."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/1834/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/1/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/1635/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/1636/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/7018/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8543/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8552/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8553/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8554/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8555/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8556/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8557/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8558/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8559/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/8565/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/10287/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/10288/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/10289/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/10290/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/10291/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/10292/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/10293/?format=api"
    ],
    "dataLineage": "Data are generated by the ERA-Interim project at European Centre for Medium-Range Weather Forecasts (ECMWF) before being prepared by ECMWF and uploaded to Centre for Environmental Data Analysis (CEDA) for ingestion into the archive.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/4119/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/6305/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/6302/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/26693/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/26691/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/26692/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/26694/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/26695/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/26696/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/26698/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/26697/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/109202/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": null,
    "procedureComputation": "https://api.catalogue.ceda.ac.uk/api/v2/computations/6306/?format=api",
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2536/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "registered",
            "accessRoles": null,
            "label": "registered: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/specific_licences/ecmwf-era-products.pdf",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}