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/7848/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 7848,
    "uuid": "3d966add9811374d81fc46d4dee2cfdc",
    "title": "NCAVEO: Project for On-Board Autonomy (PROBA) Compact High Resolution Imaging Spectrometer (CHRIS) data collected over Chilbolton",
    "abstract": "This dataset compromises data collected by the Compact High Resolution Imaging Spectrometer (CHRIS) over Chilbolton, 17th June 2006, as part of the Network for Calibration and Validation of EO data (NCAVEO) 2006 Field Campaign. The data were collected in Mode 1, which has 34 metre pixel size and 62 spectral bands between 411 nm and 997 nm, giving a ground resolution of 34 metres. \r\n\r\nSurrey Satellite Technology Ltd is the owner of all data directly resulting from in-flight operation of the CHRIS instrument flown on- board the ESA PROBA spacecraft. All publications on the CHRIS instrument or data obtained from the CHRIS development and/or operation should therefore make explicit reference to Surrey Satellite Technology Ltd, the CHRIS instrument and the ESA PROBA mission. The L3b Directory contains data created by Ted Milton from the L1b, after having been destriped and registered to the OS grid.\r\n\r\nFor more information on the structure and format of the data please see the associated metadata PDF for the dataset in linked documentation.  ",
    "keywords": "NCAVEO, CHRIS, CHILBOLTON",
    "publicationState": "published",
    "dataPublishedTime": "2007-10-16T22:20:36",
    "doiPublishedTime": null,
    "updateFrequency": "notPlanned",
    "status": "completed",
    "result_field": {
        "ob_id": "https://api.catalogue.ceda.ac.uk/api/v2/observations/12661/?format=api",
        "dataPath": "/neodc/ncaveo_field/data/CHRIS_Proba",
        "oldDataPath": [],
        "storageLocation": "internal",
        "storageStatus": "online",
        "volume": 964461559,
        "numberOfFiles": 20,
        "fileFormat": "Level 1 data is in HDF format.\r\nLevel 3 data is in HDR format. "
    },
    "timePeriod": "https://api.catalogue.ceda.ac.uk/api/v2/times/2251/?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/66078/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/phenomona/66079/?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": [
        "https://api.catalogue.ceda.ac.uk/api/v2/identifiers/5098/?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/32374/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32379/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32380/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32373/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32376/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32377/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32378/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/32375/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": "https://api.catalogue.ceda.ac.uk/api/v2/composites/7855/?format=api",
    "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"
        }
    ]
}