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/7974/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 7974,
    "uuid": "dae0e67b8f878bc03cefb59c4acac33b",
    "title": "NCAVEO: Version 1 of ground data collected during Chilbolton reconnaissance survey for Land Cover Map 2007",
    "abstract": "As part of the Centre for Ecology and Hydrology Land Cover 2007 Pilot Project, a reconnaissance survey was undertaken on 12th May 2006 in a 60 x 60 km area (bounded by Ordnance Survey National Grid Reference X = 400000 to 460000, Y = 095000 to 155000) which included the Network for Calibration and Validation in Earth Observation (NCAVEO) test site. A recording tablet device was used for acquiring ground data for sample points in the defined area.\r\n\r\nThe dataset consists of an ESRI shape file of point data, containing all the points recorded on a tablet device. Each point has a British National Grid X and Y co-ordinate and a class code. The dataset has not been checked or edited yet and a few of the records will be erroneous. The most obvious errors will be two or more points with identical locations but different codes, the final code will be the correct one. Some of the points for Salisbury Plain lie just outside the test area boundaries. A key to abbreviations used for field recording is also included and a list of thematic land cover classes and their codes to aid field reconnaissance, as used for Land Cover Map 2000. ",
    "keywords": "NCAVEO, LANDCOVER MAP, CHILBOLTON",
    "publicationState": "published",
    "dataPublishedTime": "2008-10-07T14:48:46",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/12681/?format=api",
        "dataPath": "/neodc/ncaveo_field/data/Land_cover",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 4585487,
        "numberOfFiles": 40,
        "fileFormat": "All data is in ESRI shape file format, compatible in GIS software packages such as ArcGIS. PDF files are also included providing the name and crop type for the northern and southern areas of the Chilbolton validation site. "
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/2280/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/172/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "These data were provided to NEODC by university of Southampton, who carried out work to convert formats to NASA-Ames, and write metadata documents. The metadata documents describing the processing are archived alongside the data as PDF files.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/5185/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/7827/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/7824/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/30128/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32664/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32669/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32666/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32667/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32668/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32670/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32663/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32665/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/7977/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2522/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "registered",
            "accessRoles": null,
            "label": "registered: None group",
            "licenceURL": "http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
            "licenceClassifications": "any"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}