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/9029/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 9029,
    "uuid": "36e74097dc67e04f7edc35a7c387cc2b",
    "title": "Data from the Photographic Camera on-board the Piper PA31 Navajo Chieftain G-NERC Aircraft during Flight 83/16 over the Derbyshire Area",
    "abstract": "The Airborne Research & Survey Facility (ARSF, formerly Airborne Remote Sensing Facility) is managed by NERC Scientific Services and Programme Management. It provides the UK environmental science community, and other potential users, with the means to obtain remotely-sensed data in support of research, survey and monitoring programmes. The ARSF is a unique service providing environmental researchers, engineers and surveyors with synoptic analogue and digital imagery of high spatial and spectral resolution.The NEODC holds the entire archive of Airborne Thematic Mapper (ATM) and Compact Airborne Spectrographic Imager (CASI) data acquired by the NERC ARSF. High-resolution scanned digital versions of the entire collection of analogue photographs are now also available as well as selected LiDAR-derived elevation and terrain models for selected sites flown using the sensor.",
    "keywords": "ARSF, 83/16, Derbyshire",
    "publicationState": "published",
    "dataPublishedTime": "2007-10-06T00:33:13",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/9030/?format=api",
        "dataPath": "/neodc/arsf/1983/83_16",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 7776190321,
        "numberOfFiles": 580,
        "fileFormat": null
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/2557/?format=api",
    "geographicExtent": null,
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data have been provided to NEODC via a number of routes: \r\nMost data up to 2005 was provided directly from ARSF flight team (ARSF-Ops) or Andrew Wilson at CEH, on various media.\r\nData since 2008 was mostly transferred to NEODC from ARSF-Data Analysis Node (DAN) in Plymouth via rsync.\r\nData for 2006 - 2008 were provided partly from ARSF-DAN, partly from ARSF-Ops, and some from Andrew Wilson.  \r\nData from the ULM LiDAR instrument was provided, via FTP or on media, from ULM Cambridge.\r\nScanned aerial photographs were provided by Bluesky Ltd, who carried out the digitisation, on LaCiE disks. \r\nSome data (\"user_provided\") was sent to NEODC by ARSF data users.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/5839/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/9031/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/8604/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/30129/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/34930/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/34935/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/34929/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/34933/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/34934/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/34936/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/34932/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/34931/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/9032/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2522/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "registered",
            "accessRoles": null,
            "label": "registered: None group",
            "licenceURL": "http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}