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/26628/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 26628,
    "uuid": "656b9c8effd0470080a8797e90c5ac44",
    "title": "CMORPH 0.25 degree 3-hourly precipitation estimates",
    "abstract": "This dataset contains 0.25 degree resolution 3-hourly global Climate Prediction Center morphing method (CMORPH) precipitation data. CMORPH is the CPC Morphing technique which derives precipitation estimates from low orbiter satellite microwave observations.",
    "keywords": "CMORPH, rainfall, precipitation",
    "publicationState": "published",
    "dataPublishedTime": "2018-10-12T15:56:54",
    "doiPublishedTime": null,
    "updateFrequency": "",
    "status": "ongoing",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/26629/?format=api",
        "dataPath": "/badc/cmorph/data/0.25deg-3HLY",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 13893690603,
        "numberOfFiles": 8032,
        "fileFormat": "Data are binary formatted"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/7154/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/529/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data taken as is from National Oceanic and Atmospheric Administration.  https://ftp.cpc.ncep.noaa.gov/precip/CMORPH_V1.0/CRT/0.25deg-3HLY/",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/26537/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/26630/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/193355/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/111895/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/111896/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/111898/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/111900/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/111901/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/111902/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/111899/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/111894/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/132767/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/111897/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/168853/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": null,
    "procedureComputation": "https://api.catalogue.ceda.ac.uk/api/v2/computations/26528/?format=api",
    "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"
        }
    ]
}