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/6540/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 6540,
    "uuid": "447bea7b938c96fa567b2f45dec48956",
    "title": "APPRAISE ACES: University of Manchester Condensation Particle Counter Data",
    "abstract": "The ACES (Aerosol Coupling in the Earth System) project was an integrated research programme that aims to reduce uncertainties in our fundamental understanding of the formation of BSOA (Biogenic Secondary Organic Aerosol) and the subsequent impact on atmospheric composition, through coordinated chamber studies, field studies, process model development, and application of atmospheric models of chemistry and transport to assess coupling and feedbacks in the Earth system.\r\n\r\nThe dataset contains measurements of concentrations of aerosols between 50nm and 2nm, using a TSI Condesation Particle Counter model 3025A, near ground level below the rainforest canopy at the nursery site. These data were collected from the 9th to 23rd of July 2008 by the University of Manchester condensation particle counter based at the forest in-canopy site located at the FACE (Forests Absorbing CO2 Emissions) nursery at the Sabahmas Estate oil plantation in Malaysia.",
    "keywords": "APPRAISE ACES, Aerosol, particle counter",
    "publicationState": "published",
    "dataPublishedTime": "2009-07-13T15:24:22",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/6541/?format=api",
        "dataPath": "/badc/appraise/data/aces/man-cpc",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 290153,
        "numberOfFiles": 2,
        "fileFormat": "Data are NASA Ames formatted\r\n\r\n"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/3315/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/522/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/57490/?format=api"
    ],
    "dataLineage": "Data for the period 2005 to 2010, provided as is by the APPRAISE campaign participants for archiving at the BADC.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/4280/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/8351/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/6531/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/6518/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28300/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28301/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28302/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28303/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28305/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/41902/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/41906/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/28299/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/46744/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/41903/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/74192/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/6542/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2526/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "public",
            "accessRoles": null,
            "label": "public: None group",
            "licenceURL": "http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}