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Basic API operations#

The GeoDataHub Web API is based on REST principles. Readers not familiar with REST APIs are encouraged to understand the basics before reading on.

Data resources are accessed via standard HTTP requests. Where possible, the web API uses appropriate HTTP verbs for each action.

Method Action
GET Retrieves resources
POST Creates resources
PUT Changes and/or replaces resources
DELETE Deletes resources

The API is split into operations on different resources. Operations specific to datasets use the URI Depending on the HTTP method the same URI can get, add, change, or remove datasets. See the examples section for more.

Global data model#

Each dataset contains a fixed set of metadata attributes defined by the platform and a variable set of metadata defined by the schema. The schema specific parameters are stored under the distribution_info key while all other parameters exists for all datasets,

  "identifier": "6376f381-09f0-4dbe-a994-a88a4847defe",
  "owner": "aa59467e-9aef-4854-a762-920fe20a9747",
  "organization": "00000000-0000-0000-0000-000000000000",
  "datatype": "",
  "citation": "",
  "description": "Odense Syd, historiske Wenner data",
  "larger_work": "",
  "distribution_info": {
    "Ident": "dk.mim.ode.wenner-odensesyd.Lindved_WEN_3",
    "Project": "Odense Syd, historiske Wenner data",
    "Purpose": "saarbarhed",
    "Contractor": "COWI A/S",
    "Dataset Id": 700849,
    "Project Id": 1508,
    "Maximum RHoa": 57.0,
    "Minimum RHoa": 46.0,
    "Inserted Date": "2009-01-09",
    "Project Ident": "dk.mim.ode.wenner-odensesyd",
    "Maximum A-distance": 25.0,
    "Minimum A-distance": 25.0,
    "Maximum Focus Depth": 12.976,
    "Minimum Focus Depth": 12.976,
    "Number Of Positions": 24
  "result": {
    "download_link": ""
  "projected_geometry": {
    "type": "LineString",
    "coordinates": [

The platform specific attributes are defined in the API reference. For convenience the most important are listed below,

Parameter Definition
identifier Random unique identifier following the uuid v4 format (ex. 6376f381-09f0-4dbe-a994-a88a4847defe)
result JSON encoded list with information linking the metadata information with one or more files
projected_geometry The 2D geometry, in GeoJSON format, of the dataset (POINT, LINE, or POLYGON)
datatype The full schema URI that defines the distribution_info section
distribution_info Dataset specific metadata attributes

The variable names are based on the INSPIRE Geoph Measurement class.

The result section#


The result document and backend logic is still under development and is not considered stable.

Metadata is linked to the actual files or data streams containing the data through the result parameter. The file information is encoded as JSON allowing flexibility in the possible parameters to include. The result parameter must include the following attributes,

  • uri: Local or remote path to the file or data stream
  • protocol: The protocol used to access the data (e.g. HTTP, FTP, FILE, etc)
  • file extension: The file extension (e.g. pdf, las etc.)
  • source: The software or instrument used to generate, process or transform the data

Possible additional attributes are,

  • md5: A md5 hash sum of the file content
  • license: URL to the terms of use for public or commercial data

Example of the result parameter,

  "uri": "",
  "location": "HTTPS",
  "file extension": "las",
  "source": "unknown",
  "md5": "060b49d83ba4ea60aefcde8885bad26c"

Example requests#

Description HTTP Method Request format
Get a specific Dataset with ID 6376f381-09f0-4dbe-a994-a88a4847defe GET
Add a new dataset (See required payload) POST
Get all datasets with schema GET{"": ""}
Get all Geolog datasets starting below 10 ft GET{"":{"DepthStartFt": {"$gt": 10}}}
Get all data within a polygon GET{"geometry":{\"$contains\":\"POLYGON((7.9 55.4,8.1 55.4,8.1 55.6,7.9 55.6,7.9 55.4))\"}}

Search format#

GeoDataHub supports three modes of search,

  • Metadata search: Find all datasets with a specific metadata attribute
  • Datatype search: Find all datasets of a specific datatype
  • Geography search: Find all datasets within a geographic area

Users can freely combine different modes depending on their needs.

A dataset search encodes the query as a JSON formatted parameter in the URL. All search requests are sent to the URL with the query encoded as q (e.g."YOUR QUERY").

The search either contains a schema or geometry at the top-level. To search for all Geolog data send the following query,

"": ""

The URL for this query is,

GET{"": ""}

  "Authorization": "NgCXRK...MzYjw"

The empty value indicates no filtering is needed beyond the schema. A search for all Geolog data within Florida is,

    "StateName": "Florida"

StateName is defined in the Geolog schema.

Currently, the query language supports two simple logical operators ($lt less than and $gt greater than). To filter to only logs in Florida that are also deeper than 90 ft,

"": {
    "StateName": "Florida",
    "DepthEndFt": {"$gt": 90}

Query parameters are additive so both conditions are required on the dataset. The logical OR operation (i.e. one or the other) is currently not supported.

Searching within a geographic region is supported using the top-level geometry parameters. The geometry is defined by a polygon encoded as Well known text.

"geometry": {
    "$contains": "POLYGON((7.9 55.4,8.1 55.4,8.1 55.6,7.9 55.6,7.9 55.4))",

Since no additional constraints are imposed the query above returns all datasets within the polygon.

Finally, let's combine two search modes in a single query,

"": {
    "Category": "Electromagnetic"
"geometry": {
    "$contains": "POLYGON ((-70.39215087890625 41.16211393939692, -69.81674194335938 41.16211393939692, -69.81674194335938 41.447873389865194, -70.39215087890625 41.447873389865194, -70.39215087890625 41.16211393939692))",

This will return all Geolog datasets of the category Electromagnetic located on the island of Nantucket off the east coast of the US.