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/1478/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 1478,
    "uuid": "7b143c4f452d8a053278128f74eb50cc",
    "title": "EASOE: Central Aerological Observatory (CAO) Backscatter Sonde measurements at Dikson, Russia",
    "abstract": "The European Arctic Stratospheric Ozone Experiment is a European Commission (EC) measurement campaign undertaken in the Northern Hemisphere winter of 1991-92 to study ozone chemistry and dynamics. This dataset contains meteorological parameters from the Central Aerological Observatory in Russia.",
    "keywords": "EASOE, Backscatter sonde, Meteorology",
    "publicationState": "published",
    "dataPublishedTime": "2007-01-31T22:51:11",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/1479/?format=api",
        "dataPath": "/badc/CDs/easoe/data/balloons/backscat/dikson",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 115799,
        "numberOfFiles": 5,
        "fileFormat": "Data are NASA Ames formatted"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/433/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/778/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/13197/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/21824/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/25394/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/25404/?format=api"
    ],
    "dataLineage": "CD-ROM content uploaded as is into BADC archive for browsing purposes.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/1100/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/1438/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/1435/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/4649/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/4654/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/4648/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/4651/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/4652/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/4653/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/4655/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/4650/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/1482/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2521/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/missing_licence.pdf",
            "licenceClassifications": "unstated"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}