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/27486/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 27486,
    "uuid": "1d76c5f6007648f8b81c37cbcb62024a",
    "title": "Advanced Very High Resolution Radiometer (AVHRR) - Level 0 data from NEODAAS Dundee Satellite Receiving Station",
    "abstract": "The Advanced Very High Resolution Radiometer (AVHRR) is a broad-band, four to six-channel (depending on the model) scanner, sensing in the visible, near-infrared, and thermal infrared portions of the electromagnetic spectrum. This sensor is carried on the National Oceanic and Atmospheric Administration's (NOAA's) Polar Orbiting Environmental Satellites (POES), beginning with TIROS-N in 1978.\r\n\r\nAVHRR provides day and night imaging of land, water, and clouds as well as measurements of sea surface temperature, ice snow, and vegetation cover.\r\n\r\nNEODAAS (NERC Earth Observation Data Acquisition and Analysis Service) Dundee Satellite Receiving Station retrieved data from the NOAA satellites and initially published the products. The data were transferred to CEDA when the Dundee Satellite Receiving Station (NEODAAS Dundee node) facility was closed to continue the long term archive.",
    "keywords": "AVHRR, Radiometer",
    "publicationState": "published",
    "dataPublishedTime": "2020-09-22T12:22:35",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/27578/?format=api",
        "dataPath": "/neodc/avhrr_dundee/data/Level_0/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 9560503697698,
        "numberOfFiles": 235544,
        "fileFormat": "Data are provided in RAW format, from the NEODAAS Dundee satellite receiving station."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/7375/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/529/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data from the NOAA AVHRR instruments were collected by the NEODAAS Dundee Satellite Receiving Station. NEODAAS Dundee Satellite Receiving Station initially published the data but due to this facilities closure, these products were transferred to CEDA to archive allowing the long term archive to continue.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/30202/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/30129/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114914/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114915/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114916/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114918/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114917/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114913/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/140737/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/114912/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/27579/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2591/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/specific_licences/NOAA%20Open%20Access%20Data.pdf",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}