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/8053/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 8053,
    "uuid": "acfa8955414aef710105ef640802b9aa",
    "title": "1m resolution LiDAR-derived Digital Terrain/Surface Models (DTMs/DSMs) for cities of England and Scotland",
    "abstract": "Light Detection and Ranging (LiDAR) data was collected by The Geoinformation Group using LiDAR-equipped survey aircraft for the main urban conurbations of England and Wales (including London, Manchester, Birmingham, Liverpool, Newcastle, Edinburgh and Glasgow) as part of the Cities Revealed project, and made available through the Landmap service. The GeoInformation Group (TGG) has processed the data so that they are available as Digital Terrain Models (ground surface only) and Digital Surface/Elevation Models (the ground and all features on it), both geographic databases with height and surface measurement information in the form of regular grids with intervals of 1 or 2 m. In addition, some First Pass and Last Pass data are available. The First Pass data provides height values for the top of the canopy (i.e. buildings, trees etc.) while the Last Pulse data provides height values for the bottom of the canopy and provides information about the shape of the terrain. The data are available in img format. The Joint Information Systems Committee (JISC) funded Landmap service which ran from 2001 to July 2014 collected and hosted a large amount of earth observation data for the majority of the UK, part of which was elevation data. After removal of JISC funding in 2013, the Landmap service is no longer operational, with the data now held at the NEODC.\r\n\r\nWhen using the data please also add the following copyright statement: Cities Revealed © The GeoInformation Group yyyy",
    "keywords": "Landmap, LIDAR",
    "publicationState": "published",
    "dataPublishedTime": "2014-08-15T14:48:27",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/8054/?format=api",
        "dataPath": "/neodc/landmap/data/elevation/lidar",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 76001174622,
        "numberOfFiles": 954,
        "fileFormat": "Data are img formatted"
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/2305/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/176/?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/5235/?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/8041/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32847/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32848/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32849/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32850/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/40997/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/43263/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32846/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/108861/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/43264/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/8058/?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"
        }
    ]
}