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/6574/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 6574,
    "uuid": "7025e0c5730cdea0e18669c75cd1688b",
    "title": "UTLS-Ozone DCFZ campaign: CFARR Chilbolton Advanced Meteorological Radar images",
    "abstract": "Data from the Upper Troposphere Lower Stratosphere (UTLS) programme's round 1 research project \"Dynamics and Chemistry of Frontal Zones\" (DCFZ). DCFZ investigated the role of frontal shear zones in determining upper tropospheric chemical distributions. This dataset contains Chilbolton radar images.",
    "keywords": "UTLS, DCFZ, Radar",
    "publicationState": "published",
    "dataPublishedTime": "2007-03-13T15:06:33",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/6575/?format=api",
        "dataPath": "/badc/utls/data/dcfz/chilbolton",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 192716419,
        "numberOfFiles": 959,
        "fileFormat": "Images are JPG formatted"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/1931/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/152/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data were given to the BADC from Chilbolton Facility for Atmospheric and Radio Research (CFARR).",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/4292/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/14434/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/6573/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28380/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28381/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28383/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28386/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28384/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28385/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28387/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28382/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/6576/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2526/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}