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/12790/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 12790,
    "uuid": "b0ecc01a0c244162b5c4254ae03be45a",
    "title": "NCAVEO: Level 3A ARSF Compact Airbone Spectrographic Imager 2 (CASI-2) data collected on board the Dornier Do228-101 D-CALM aircraft",
    "abstract": "As part of the Network for Calibration and Validation of Earth Observation data (NCAVEO) 2006 Field Campaign, a Dornier 228 aircraft operated by the Natural Environment Research Council (NERC) Airborne Research and Survey Facility (ARSF) collected CASI-2 data on 17th June 2006. The data was collected between 10:40 am and 12:01pm GMT over Chilbolton, the campaign's study area. The aircraft  flew eight adjacent north-south flightlines to cover the whole area, and one east-west across the area, passing directly over the CFARR site. Information about data collection can be found in documentation file '168-GB06-10.pdf' in linked documentation.\r\n\r\nThe Level 3a files in this dataset have been processed using the AZGCORR software package (Azimuth Systems UK) provided by the NERC Airborne Research and Survey Facility. This produced a 2 metre pixel geo-corrected product without the use of ground control points. JPEG images of the Level 3 files are available for each flight line as band 10, 8, 6 RGB false-colour composites. The CASI data has 15 bands. The wavelength and width of these are specified in the associated metadata PDF, in linked documentation. Level 1B CASI-2 files and data collected by the Eagle instrument during the flight are also available through their separate dataset record pages, listed in linked documentation. ",
    "keywords": "NCAVEO, ARSF, CASI-2, DORNIER",
    "publicationState": "published",
    "dataPublishedTime": "2007-10-16T22:04:41",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/12792/?format=api",
        "dataPath": "/neodc/ncaveo_field/data/arsf/L3a",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 3596603200,
        "numberOfFiles": 19,
        "fileFormat": "Data is HDF formatted. "
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/2252/?format=api",
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/172/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/64847/?format=api"
    ],
    "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": [],
    "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/48891/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/48892/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/48894/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/48895/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/48896/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/48897/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/48890/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/48893/?format=api"
    ],
    "procedureAcquisition": "https://api.catalogue.ceda.ac.uk/api/v2/acquisitions/7859/?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"
        }
    ]
}