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/8220/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 8220,
    "uuid": "51c4273d47ef0130c422eafb2f99d4fe",
    "title": "Colour InfraRed (CIR) data for England and Wales",
    "abstract": "Colour InfraRed (CIR) imagery for most of England and Wales collected between 2006 and 2010 at 50cm resolution by Bluesky, and then acquired by the Landmap project. The data were collected using digital cameras mounted underneath planes. The Joint Information Systems Committee (JISC) funded Landmap service which ran from 2001 to July 2014 collected and hosted Earth Observation satellite data for the majority of the UK, part of which was CIR data. After removal of JISC funding in 2013, the Landmap service is no longer operational, with the data now held at the NEODC. The data are split into 100x100km regions that correspond to Ordnance Survey grid reference squares, and are available in GeoTiff format. Some regions are also available in ecw (Enhanced Compression Wavelet) format. Colour InfraRed imagery consists of imagery in three bands – Near InfraRed (NIR), red and green. CIR can be used study the health and variation of vegetation coverage as NIR rays are reflected at the bottom of leaves rather than the top, as with green. To aid with this, images were captured at times when plants were expected to be in full leaf. The invisible near infrared light of CIR can be \"seen\" by shifting it and the primary colours over so that near infrared wavelengths become visible as red while red wavelengths appear as green and green as blue. Blue wavelengths are shifted out of the visible portion of the spectrum and so they appear as black. On CIR imagery vegetation appears red while water generally appears black with artificial structures like buildings and roads showing as a light blue-green.\r\n\r\nWhen using these data please also include the following copyright statement: © GeoPerspectives supplied by Bluesky yyyy",
    "keywords": "",
    "publicationState": "published",
    "dataPublishedTime": "2014-07-31T09:16:53",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/8221/?format=api",
        "dataPath": "/neodc/landmap/data/optical/cir/bluesky",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 2269268788742,
        "numberOfFiles": 1255876,
        "fileFormat": "&lt;div property=\"cedacat:formats\"&gt;\r\nThe data are split into 100x100km regions that correspond to &lt;a href=\"http://www.ordnancesurvey.co.uk/resources/maps-and-geographic-resources/the-national-grid.html\"&gt;Ordnance Survey (OS) national grid&lt;/a&gt; squares and archived in the directory structure of region/year/format/data. The data are available in GeoTiff format (with GeoTiff world files (.tfw) which are data files that are used to geo-reference images to an appropriate projection scheme), with some regions also available in ecw (Enhanced Compression Wavelet) format. Geotiff files are TIFF files which have geographic metadata embedded as tags within the TIFF file. The geographic metadata can then be used to position the image in the correct location and geometry on the screen of a geographic information display, and ECW (Enhanced Compression Wavelet) files are compressed images. Most filenames start with the &lt;a href=\"http://www.ordnancesurvey.co.uk/resources/maps-and-geographic-resources/the-national-grid.html\"&gt;OS grid reference&lt;/a&gt; of the area covered by the file, in the format AA0000. GeoTiff files can be opened by most Geographic Information Systems (GIS) and Image Processors (IP) such as the freely available &lt;a href=\"http://www.brockmann-consult.de/cms/web/beam/\"&gt;Basic ERS &amp;amp; Envisat (A)ATSR and Meris Toolbox (BEAM)&lt;/a&gt;. The ecw (Enhanced Compression Wavelet) files can also be opened in most image viewing/editing software, including open/free software such as &lt;a href=\"http://www.hexagongeospatial.com/products/remote-sensing/erdas-er-viewer\"&gt;Erdas ER viewer&lt;/a&gt;\r\n&lt;/div&gt;\r\n\r\n\r\n"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/2354/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/184/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data collected and prepared by the Landmap team before a copy of the data were obtained by NEODC directly from Landmap.",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/5295/?format=api"
    ],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/8044/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/8212/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/33163/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/33165/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/33166/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/42101/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/33164/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/42103/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/33167/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108874/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/42102/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/8224/?format=api",
    "procedureCompositeProcess": null,
    "procedureComputation": null,
    "permissions": [
        {
            "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/2588/?format=api",
            "useLimitation": null,
            "accessConstraints": null,
            "accessCategory": "restricted",
            "accessRoles": "landmap",
            "label": "restricted: landmap group",
            "licenceURL": "https://artefacts.ceda.ac.uk/licences/specific_licences/landmap.pdf",
            "licenceClassifications": "academic, specific"
        }
    ],
    "discoveryKeywords": [
        {
            "ob_id": 1138,
            "name": "NDGO0003"
        }
    ]
}