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/24139/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 24139,
    "uuid": "89e8e254ed874c1cb446e034de9b625b",
    "title": "INTACASA-RS EUFAR HYPERFOREST Flight, 2010-08-24: hyperspectral remote sensing measurements",
    "abstract": "Hyperspectral remote sensing measurements using the INTA Airborne Hyperspectral Scanner and INTA Compact Airborne Spectrographic Imager 1500i instruments onboard the CASA 212 RS - INTA aircraft for the HyperForest - Advanced airborne hyperspectral remote sensing to support forest management (HYPERFOREST) project (flight reference: intacasa-rs_20100824_hyperforest).\r\n\r\nData were collected over the Belgium area.",
    "keywords": "HYPERFOREST, EUFAR, aircraft, hyperspectral, remote sensing",
    "publicationState": "citable",
    "dataPublishedTime": "2015-07-31T14:59:44",
    "doiPublishedTime": "2018-01-17T09:40:36",
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/24138/?format=api",
        "dataPath": "/badc/eufar/data/projects/hyperforest/intacasa-rs_20100824_hyperforest",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 18753622012,
        "numberOfFiles": 72,
        "fileFormat": "Data are netCDF and ENVI Binary formatted. Ancillary files may be plain ASCII or PDF formatted. Image files may be PNG or JPG formatted."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/6570/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/1887/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data were collected by instrument scientists during the flight before preparation and delivery for archiving at the Centre for Environmental Data Analysis (CEDA).",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/9411/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/19605/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/6382/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/24140/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/98984/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/98977/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/98980/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/98981/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/98982/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/98983/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/106172/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/98976/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/106173/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/105941/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/106174/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/24136/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2528/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "http://creativecommons.org/licenses/by/4.0/",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}