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/19019/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 19019,
    "uuid": "1b95268e94d44ede88eac442d0b0d473",
    "title": "Sentinel 3A Synthetic Aperture Radar Altimeter (SRAL) Level 1B data",
    "abstract": "This dataset contains level 1b altimetry data from the Synthetic Aperture Radar Altimeter (SRAL) aboard the European Space Agency (ESA) Sentinel 3A Satellite. Sentinel 3A was launched on the 16th of February 2016. \r\n\r\nThese data contain geo-located and fully calibrated multi-looked High-Resolution power echoes. \r\nThese level 1b products are geo-located and fully calibrated multi-looked High-Resolution power echoes. Complex echoes (In-phase (I) and Quadrature (Q)) for the Low-Resolution Mode (LRM) and/or Synthetic Aperture Radar (SAR) mode both for C Band and Ku band. When the altimeter is in SAR mode, this product also contains the so-called Pseudo LRM (PLRM) echoes. All Sentinel-3 Non-Time Critical (NTC) products are available in less than 30 days. Data are provided by ESA and are made available via CEDA to any registered user. The level 1B SAR product contains the same variables as the level 1B-S product except for the waveform and the stack characterisation parts. A level 1B waveform is the average of each stack and is provided in samples (power waveform) in the frequency domain (range domain).\r\n\r\nData are provided by ESA and are made available via CEDA to any registered user.",
    "keywords": "Sentinel, Synthetic Aperture Radar Altimeter, SRAL",
    "publicationState": "published",
    "dataPublishedTime": "2022-12-15T09:03:19",
    "doiPublishedTime": null,
    "updateFrequency": "continual",
    "status": "ongoing",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/26983/?format=api",
        "dataPath": "/neodc/sentinel3a/data/SRAL/L1_SRA/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 6398005075261,
        "numberOfFiles": 205558,
        "fileFormat": "Data are provided by ESA in zipped SAFE format."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/8993/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/529/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data collected and prepared by European Space Agency (ESA). Downloaded from the Sentinel hubs for use by the CEDA community.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/12321/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/30129/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/32818/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71556/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71555/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71559/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/113223/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71557/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/146257/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71552/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71554/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71558/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/71553/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/146258/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": "https://api.catalogue.ceda.ac.uk/api/v2/composites/19018/?format=api",
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2586/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://sentinel.esa.int/documents/247904/690755/Sentinel_Data_Legal_Notice",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": []
}