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/24643/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 24643,
    "uuid": "708d98ac4b3d4784bd38521a4993b5b7",
    "title": "ARSF 2015_169a - EUFAR MEDHY2CON/EUFAR15_38 Flight: hyperspectral remote sensing measurements",
    "abstract": "Hyperspectral remote sensing measurements using the ARSF AsiaFENIX hyperspectral imager  and ARSF Optech Airborne Laser Terrain Mapper 3033 LIDAR instruments onboard the NERC ARSF Dornier Do228-101 D-CALM Aircraft for the MEDhy^2CON- MEDiterranean HYdrological and HYperspectral monitoring of landscape CONnectivity in contrasting Mediterranean insular catchments (Mallorca, Spain) (EUFAR15_38) project (flight reference: 2015_169a).\r\n\r\nData were collected over the Mallorca, Spain area.\r\n",
    "keywords": "EUFAR15_38, MEDHY2CON, aircraft, hyperspectral, remote sensing",
    "publicationState": "published",
    "dataPublishedTime": "2017-01-30T17:37:50",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/24642/?format=api",
        "dataPath": "/neodc/arsf/2015/EUFAR15_38/EUFAR15_38-2015_169a_Mallorca",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 170991972194,
        "numberOfFiles": 295,
        "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/6684/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/1970/?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": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/19965/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/24644/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/6382/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/100893/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/100885/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/100889/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/100890/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/100891/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/100892/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/106498/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/100884/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/106499/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/106046/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/106500/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/24640/?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"
        }
    ]
}