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/39499/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "ob_id": 39499,
    "uuid": "6b143f0feab14045b91556438b48cceb",
    "title": "TCOM-CH4: TOMCAT CTM and Occultation Measurements based daily zonal stratospheric methane profile dataset (1991-2021) constructed using machine-learning",
    "abstract": "This dataset contains daily zonal stratospheric methane profile outputs between 1991-2021 simulated by the TOMCAT model.\r\n\r\nThe TOMCAT simulation is performed at T64L32 resolution that is similar to the one used in Dhomse et al., (2021, 2022) for 1991-2021 time period. \r\n\r\nCollocated methane profiles are divided in five latitude bins: SH polar (90S-50S), SH mid-lat (70S-20S), tropics (40S-40N), NH mid-lat (20N-70N) and NH polar (50N-90N). Initially, differences are calculated for each zonal bins for 46 height levels (15km to 60km). Then separate XGBoost regression models are trained for the methane differences between TOMCAT and measurements at each level for a given latitude bin. \r\n\r\nThe same model is used for all day/night time (2 X11323 days) TOMCAT output sampled at 1.30 am and 1.30 pm local time at the equator. Thus bias corrections for a given model grid are added to the original TOMCAT day and night time profiles. Height resolved data are then interpolated on 28-pressure levels (300 - 0.1hPa). For overlapping latitude bins, we use averages and then calculate daily zonal mean values.  For more details regarding this methodology see the associated presentation on Zenodo.\r\n\r\nDataset also includes two files containing daily mean zonal mean methane profiles on height (15-60 km) and pressure (300-0.1 hPa) levels:\r\n\r\n- zmch4_TCOM_hlev_T2Dz_1991_2021.nc – height level data (15 to 60 km)\r\n- zmch4_TCOM_plev_T2Dz_1991_2021.nc – pressure level data (300 to 0.1 hPa)\r\n\r\nThe exact cause of unusual methane variations during 1991-1994 is unknown, however some recent studies argue that it could be due to sudden changes in methane loss processes following Mount Pinatubo eruption as well as significant changes in methane emissions following collapse of the Soviet Union.",
    "keywords": "stratosphere, methane profiles, satellite, machine-learning",
    "publicationState": "preview",
    "dataPublishedTime": null,
    "doiPublishedTime": null,
    "updateFrequency": "",
    "status": "pending",
    "result_field": null,
    "timePeriod": null,
    "geographicExtent": "https://api.catalogue.ceda.ac.uk/api/v2/bboxes/529/?format=api",
    "nonGeographicFlag": false,
    "phenomena": [],
    "dataLineage": "Data were produced by the project team and supplied for archiving at the Centre for Environmental Data Analysis (CEDA).",
    "removedDataTime": null,
    "removedDataReason": "",
    "language": "English",
    "identifier_set": [],
    "projects": [
        "https://api.catalogue.ceda.ac.uk/api/v2/projects/5002/?format=api"
    ],
    "observationcollection_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/observationcollections/30127/?format=api"
    ],
    "responsiblepartyinfo_set": [
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/192647/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/192648/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/192649/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/192650/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/192651/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/192652/?format=api",
        "https://api.catalogue.ceda.ac.uk/api/v2/rpis/192653/?format=api"
    ],
    "procedureAcquisition": null,
    "procedureCompositeProcess": null,
    "procedureComputation": "https://api.catalogue.ceda.ac.uk/api/v2/computations/39527/?format=api",
    "permissions": [],
    "discoveryKeywords": []
}