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/28050/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 28050,
    "uuid": "235ff4a040854dcd8dfb754bbb898479",
    "title": "Met Office daily weather reports 1900-1910",
    "abstract": "This dataset contains meteorological observations taken from 72 locations around Great Britain, Ireland and Europe published in the 1900-1910 Met Office Daily Weather Reports (DWRs). These records were produced as part of the Operation Weather Rescue project.\r\n\r\nTwice daily observations of mean sea level pressure and dry bulb temperature, along with daily wet bulb, maximum and minimum temperatures and total rainfall, were sent to the Met Office via telegraph for publication the DWRs. Some of the locations cover the entire 11 year period whereas others stopped reporting and may have been replaced by another location, and some locations were included in the DWRs from a later date. Additional observations of mean sea level pressure, dry bulb temperature and wet bulb temperature at 2pm are included for 1900 but these observations were no longer included in the DWRs after 1900. From November 1908 the German stations replaced wet bulb temperature with relative humidity.\r\n\r\nThe data is stored in two formats: in daily csv files with observations for each station and in Station Exchange Format (SEF) files for each station in separate variables. SEF is a human-readable text format saved as .tsv (tab separated values). In the csv files units are inches of mercury (inHg) for mean sea level pressure, degrees Fahrenheit (F) for all temperature variables, inches for rainfall and percent (%) for relative humidity. In the SEF files the units are hectopascals (hPa) for mean sea level pressure, degrees Celsius (C) for all temperature variables, millimetres (mm) for rainfall and percent for relative humidity.",
    "keywords": "Met Office, Reports, Weather, Meteorology",
    "publicationState": "published",
    "dataPublishedTime": "2019-10-24T13:02:12",
    "doiPublishedTime": null,
    "updateFrequency": "",
    "status": "ongoing",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/28049/?format=api",
        "dataPath": "/badc/deposited2019/operation-weather-rescue/data/daily-weather-reports-1900-1910/",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 79437696,
        "numberOfFiles": 4486,
        "fileFormat": "Data are csv and SEF formatted."
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/7543/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/2535/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data were digitised as part of the Operation Weather Rescue project and sent to the Centre for Environmental Data Analysis (CEDA) for archiving.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/27037/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/28048/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118122/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118131/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118128/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118124/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118125/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118126/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118127/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118129/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118130/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/118123/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/168796/?format=api"
    ],
    "procedureAcquisition": null,
    "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"
        }
    ]
}