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/13797/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 13797,
    "uuid": "30d95d1041fc4ec59b4fabcce1e656af",
    "title": "Total Ozone Mapping Spectrometer (TOMS): NIMBUS-7 reflectivity measurements (1978-1993) version 1",
    "abstract": "Data from the Total Ozone Mapping Spectrometer (TOMS), which used backscattered ultraviolet radiance to infer total column ozone measurements (gridded daily for the entire globe). This 2 CD-ROM set contains the latest version (version 7) of reflectivity data from the TOMS (Total Ozone Mapping\r\nSpectrometer) instrument onboard the Nimbus 7 spacecraft.  Data covering the entire Nimbus 7 TOMS lifetime, November 1, 1978 through May 6, 1993, are given as daily files of gridded data, as\r\nzonal means, and as monthly averages.\r\n\r\nA similar CD-ROM set (OPT_004A and OPT_004B) containing TOMS total ozone values is also currently available.  A CD-ROM of version 7 data from the Meteor 3 TOMS instrument (August 1991 -December 1994) will be produced soon.\r\n",
    "keywords": "ATMOSPHERICRADIATION ATMOSPHERE ATMOSPHERICCHEMISTRY",
    "publicationState": "published",
    "dataPublishedTime": "1996-12-10T02:16:33",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/13798/?format=api",
        "dataPath": "/badc/CDs/toms_CDs/nimbus7_toms_reflect_v1",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 577128711,
        "numberOfFiles": 3602,
        "fileFormat": "Data are ASCII formatted and images are GIF formatted"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/125/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/1/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/21771/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/22890/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/25394/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/26002/?format=api"
    ],
    "dataLineage": "Data collected by NASA's Total Ozone Mapping Spectrometer (TOMS) and published on CD-ROM. A copy of the data were obtained by the BADC to assist in data access and to ensure long term preservation.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/456/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/453/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/52839/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/52837/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/52836/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/52835/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/52841/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/52842/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/52843/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/52840/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/52838/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": "https://api.catalogue.ceda.ac.uk/api/v2/composites/462/?format=api",
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2521/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/missing_licence.pdf",
            "licenceClassifications": "unstated"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}