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/3090/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 3090,
    "uuid": "f0cdcbcc196f878915812a6758faf474",
    "title": "Polluted Troposphere TORCH1: University of Leeds Wind, Relative humidity and temperature measurements at Writtle College",
    "abstract": "Tropospheric ORganic CHemistry Experiment (TORCH) was a Natural Environment Research Council (NERC) Polluted Troposphere Research Programme project (Round 1 - NER/T/S/2002/00145. Duration 2002 - 2005) led by A. Lewis, University of York. TORCH 1 took place in July and August 2003 at Writtle College, near Chelmsford, Essex.\r\n\r\nThis dataset contains temperature, relative humididty, wind speed and wind direction measurments taken using Campbell Scientific basic weather station",
    "keywords": "Polluted Troposphere, TORCH1, Wind, Temperature, Humidity",
    "publicationState": "published",
    "dataPublishedTime": "2007-03-15T18:36:33",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/3091/?format=api",
        "dataPath": "/badc/polluted-tropo/data/torch/torch1_2003/leeds-metsensor",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 3459785,
        "numberOfFiles": 2,
        "fileFormat": "Data are NASA Ames formatted"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/829/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/892/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/52651/?format=api"
    ],
    "dataLineage": "Data were collected at Writtle College, near Chelmsford, Essex between 27th July - 30th August 2003 and in April and May 2004 at Weybourne Atmospheric Observatory. Data files supplied as is to the BADC by the campaign participants.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/2120/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/14344/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/3058/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/13822/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/13825/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/13827/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/55523/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/13821/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/13820/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/13823/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/13824/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/55524/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/55525/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/55526/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/3092/?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"
        }
    ]
}