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/4851/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 4851,
    "uuid": "8075c2db8e687fe3aa6d26d9b7d0bf48",
    "title": "Convective Storm Initiation Project (CSIP): Radiosonde Data from the University of Reading",
    "abstract": "The data were collected by radiosonde at Reading by Convective Storm Initiation Project (CSIP) participants at the University of Reading between the 16th of June 2005 and the 25th of August 2005. Data include measurements of air temperature, relative humidity, wind speed and direction, and air pressure.",
    "keywords": "CSIP, UFAM",
    "publicationState": "published",
    "dataPublishedTime": "2008-08-01T11:30:54",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/4852/?format=api",
        "dataPath": "/badc/csip/data/reading-radiosonde",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 65640597,
        "numberOfFiles": 261,
        "fileFormat": "Data are NASA Ames formatted."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/1401/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/711/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/58215/?format=api"
    ],
    "dataLineage": "Data were collected by the collected by the instrument scientist before preparation and delivery to the Convective Storm Initiation Project (CSIP) participants and then to the BADC for archiving.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/3239/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/4614/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/4611/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/21998/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/50231/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/21997/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/21999/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/22000/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/22001/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/22003/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/42712/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/54580/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/4853/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2543/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "registered",
            "accessRoles": null,
            "label": "registered: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/missing_licence.pdf",
            "licenceClassifications": "unstated"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}