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/7995/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 7995,
    "uuid": "8c05f529402fc0fbbb57bbc01c5641c8",
    "title": "NCAVEO: NERC Field Spectroscopy Facility (FSF) Soil Reflectance data collected using an ASD FieldSpec Pro at Brockley field, near Chilbolton",
    "abstract": "Spectra measurements were collected for a patch of bare soil at the northern corner of Brockley field, near Chilbolton, to establish the field's typical soil background reflectance. The measurements were recorded on the 18th June 2006 as part of the Network for Calibration and Validation of Earth Observation (NCAVEO) 2006 Field Campaign. An ASD Fieldspec Pro Instrument (FR Unit No. 6408, NCAVEO Code N4406), owned by Newcastle University, was used with an 8° FOV foreoptic. All measurements were collected using a 1.5m extension probe from a height of ~1.35 metres above the ground, with the foreoptic positioned approximately 1.5m from the tramline, in a vertical plane unless stated otherwise. At each pair of coloured flags 11 sets of panel/target measurements were taken at approximately 1 metre intervals moving from left [01] to right [11] facing from the tramline towards the crop. 30 samples were averaged per data point. Times recorded are UTC (GPS time). ",
    "keywords": "",
    "publicationState": "published",
    "dataPublishedTime": "2008-10-08T13:43:09",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/12671/?format=api",
        "dataPath": "/neodc/ncaveo_field/data/Field_spectra/Soil_Spectra",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 315787,
        "numberOfFiles": 6,
        "fileFormat": "The spectra are in HDR and SPC format, and are ENVI compatible. A plot of the spectra with 'noisy' wavelengths removed is also included in JPG format and a log sheet of the data collection in a PDF file. "
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/2285/?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/5201/?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/32716/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32721/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32715/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32719/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32720/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32722/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32718/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32717/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/7997/?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"
        }
    ]
}