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/25924/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 25924,
    "uuid": "aa09603e91b44f3cb1573c9dd415e8a8",
    "title": "ESA Greenhouse Gases Climate Change Initiative (GHG_cci): Column-averaged CH4 from SCIAMACHY generated with the WFMD algorithm (CH4_SCI_WFMD), version 4.0",
    "abstract": "The CH4_SCI_WFMD dataset comprises level 2, column-averaged dry-air mole fractions (mixing ratios) of methane (XCH4). It has been produced using data acquired from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) on board the European Space Agency's (ESA's) environmental research satellite ENVISAT, as part of the ESA's Greenhouse Gases Climate Change Initiative (GHG_cci) project.   This version of the data is version 4.0, and forms part of the Climate Research Data Package 4.\r\n\r\nThe Weighting Function Modified DOAS (WFMD) algorithm is a least-squares method based on scaling pre-selected atmospheric vertical profiles. A second product is also available, which has been generated from the SCIAMACHY data using the IMAP algorithm. \r\n\r\nThe data product is stored per day in separate NetCDF-files (NetCDF-4 classic model). The product files contain the key products and other information relevant for the use of the data e.g. the averaging kernels. Note that the results since November 2005 are considered to be of reduced quality in comparison to the earlier results because the extended-wavelength part (1590-1770 nm) of SCIAMACHY's channel 6, covering the methane 2v3 absorption band used for the methane retrieval, is subject to irreversible displacement damage induced by high energy solar protons, which occurs from time to time at individual detector pixels. Therefore several affected detector pixels had to be excluded for the time period since November 2005. \r\n\r\nFor further information on the product, including details of the WFMD algorithm and the SCIAMACHY instrument, please see the associated product user guide (PUG) or the Algorithm Theoretical Basis Documents.",
    "keywords": "ESA, GHG, CCI, CH4, WFMD",
    "publicationState": "published",
    "dataPublishedTime": "2018-03-19T21:10:04",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/25925/?format=api",
        "dataPath": "/neodc/esacci/ghg/data/crdp_4/SCIAMACHY/CH4_SCI_WFMD/v4.0/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 3050499629,
        "numberOfFiles": 3211,
        "fileFormat": "Data are in NetCDF format"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/3849/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/529/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54763/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54764/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/55532/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/55533/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/55535/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/63576/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69362/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69622/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69623/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69624/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69625/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69626/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69627/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69628/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69629/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69630/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69631/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69632/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69633/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69634/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/69635/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/74650/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/74654/?format=api"
    ],
    "dataLineage": "Data were processed by the ESA CCI GHG project team and supplied to CEDA as part of the ESA CCI Open Data Portal Project",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/13295/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/12808/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108367/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108361/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108362/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108364/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108366/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108363/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108360/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108365/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108368/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/8036/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2564/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/specific_licences/esacci_ghg_terms_and_conditions.pdf",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        },
        {
            "ob_id": 1140,
            "name": "ESACCI"
        }
    ]
}