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/26173/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 26173,
    "uuid": "0f4570c780ba41b19a362e774509c883",
    "title": "ESA Soil Moisture Climate Change Initiative (Soil_Moisture_cci): 'Combined' Product, Version 03.3",
    "abstract": "The Soil Moisture CCI 'Combined' dataset is one of the three datasets created as part of the European Space Agency's (ESA) Soil Moisture Essential Climate Variable (ECV) CCI project. The product has been created by merging the \"Active\" and \"Passive\" datasets which were created for the project, these being respectively fusions of scatterometer and radiometer soil moisture products derived from the AMI-WS, ASCAT, SMMR, SSM/I, TMI, AMSR-E, WindSat, AMSR2 and SMOS satellite instruments. \r\n\r\nThe v03.3 Combined product, provided as global daily images in NetCDF-4 classic file format, presents a global coverage of surface soil moisture at a spatial resolution of 0.25 degrees. It is provided in volumetric units [m3 m-3] and covers the period (yyyy-mm-dd) 1978-11-01 to 2016-12-31. For information regarding the theoretical and algorithmic base of the product, please see the Algorithm Theoretical Baseline Document.  Other additional reference documents and information relating to the dataset can also be found on the CCI Soil Moisture project web site or within the Product Specification Document.\r\n\r\nThe data set should be cited using all three of the following references:\r\n\r\n1. Dorigo, W.A., Wagner, W., Albergel, C., Albrecht, F., Balsamo, G., Brocca, L., Chung, D., Ertl, M., Forkel, M., Gruber, A., Haas, E., Hamer, D. P. Hirschi, M., Ikonen, J., De Jeu, R. Kidd, R. Lahoz, W., Liu, Y.Y., Miralles, D., Lecomte, P. (2017). ESA CCI Soil Moisture for improved Earth system understanding: State-of-the art and future directions. In Remote Sensing of Environment, 2017, ISSN 0034-4257, https://doi.org/10.1016/j.rse.2017.07.001\r\n\r\n2. Gruber, A., Dorigo, W. A., Crow, W., Wagner W. (2017). Triple Collocation-Based Merging of Satellite Soil Moisture Retrievals. IEEE Transactions on Geoscience and Remote Sensing. PP. 1-13. 10.1109/TGRS.2017.2734070\r\n\r\n3. Liu, Y.Y., Dorigo, W.A., Parinussa, R.M., de Jeu, R.A.M. , Wagner, W., McCabe, M.F., Evans, J.P., van Dijk, A.I.J.M. (2012). Trend-preserving blending of passive and active microwave soil moisture retrievals, Remote Sensing of Environment, 123, 280-297, doi: 10.1016/j.rse.2012.03.014",
    "keywords": "ESA, Soil Moisture, CCI, Combined",
    "publicationState": "published",
    "dataPublishedTime": "2018-06-25T13:23:48",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "superseded",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/26231/?format=api",
        "dataPath": "/neodc/esacci/soil_moisture/data/daily_files/COMBINED/v03.3/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 12075789740,
        "numberOfFiles": 13942,
        "fileFormat": "Data is in NetCDF format"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/7084/?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/50512/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/52664/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/52665/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54641/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54643/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54646/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54647/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54648/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54649/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54650/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/54651/?format=api"
    ],
    "dataLineage": "Data were processed by the ESA CCI Soil Moisture project team and transferred to CEDA for the ESA CCI Open Data Portal Project.\r\nThis dataset forms part of the v03.3 Soil Moisture CCI data (doi:10.5285/b810601740bd4848b0d7965e6d83d26c. http://dx.doi.org/10.5285/b810601740bd4848b0d7965e6d83d26c )",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/13332/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/12877/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/26166/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/109475/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/109476/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/109477/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/109478/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/109479/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/109480/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110068/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/109481/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/109483/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110069/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110070/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110071/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110072/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110073/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110074/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110075/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110076/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/110077/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2535/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/specific_licences/esacci_soilmoisture_terms_and_conditions.pdf",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}