WMTS

Tidetech have developed a WMTS, a service that produces visualisations of Tidetech's data products in a tiled format compatible with web map servers. Spatial web services can be accessed at the WMTS address at https://wmts.tidetech.org/wmts/1.0.0/get-capabilities/.

Demo

A minimal functional demo of the WMTS can be seen at https://wmts.tidetech.org/demo/. Log in using your Tidetech account to access the datasets available to you. 

Technology

Tidetech WMTS is a custom implementation of the OGC WMTS standard. The demo is built on OpenLayers.

Authentication

In order to access production data, which is updated multiple times a day, users will need to authenticate themselves. Authentication can happen in two ways: via SAML, for web-based interfaces; and via HTTP Basic Authentication, for all other interfaces.

All requests should be authenticated, including requests for the capabilities document, tiles, legends, and feature info requests. Failure to authenticate will result in a 404 when accessing your private datasets.

SAML

For web-based interfaces, such as the OpenLayers demo, users can log in via SAML to their Tidetech account. Visit https://wmts.tidetech.org/auth/saml/login/ to start the log in process. Once logged in, users can log out by POSTing to https://wmts.tidetech.org/auth/saml/logout/.

HTTP Basic Authentication

For non-web based clients, authentication can be done via HTTP Basic Authentication. Users should authenticate with either their username and password, or preferably with an API key. API keys for your organisation can be found in your account portal.

Testing authentication

Applications can check theie authentication status by sending a GET request to https://wmts.tidetech.org/auth/. If the user has successfully authenticated, the response will show who they are authenticated as. If the user has not successfully authenticated, an authentication error will be returned. If the user has not supplied any authentication details, the response will say the user is anonymous.

Custom Layers

Custom layers for your organisation are configurable on an as-needs basis.

Implementation Notes

GetCapabilities

The capabilities of the WMTS are all listed in the GetCapabilities document at https://wmts.tidetech.org/wmts/1.0.0/get-capabilities/. This information includes the available datasets, the time steps associated with those datasets, where to access the tiles, legend graphics, and how to query a point for data. The WMTS specification has more information on each of these features.

The WMTS implements both REST- and KVP-style endpoints.

Time

The entire forecast for each dataset is available. Different time steps are available by changing the Time parameter in the GetTile or GetFeatureInfo requests. The available timesteps for each dataset are listed in the GetCapabilities document. Each dataset may have different timesteps available.

A Time of default will get the data from the start of the most recent forecast, which may be in the future or in the past, depending upon when the forecast was run.

See the Tidetech WMTS Capabilities Time Dimension documentation for information about the convention used in our capabilities document.

GetTile

The WMTS tiles are served from multiple subdomains, as listed in the GetCapabilities document. This allows web clients to work around a limitation in browsers, which limit the number of concurrent connections to a single domain to some small number. By serving tiles on multiple domains, the web client can speedily fetch a full screen of tiles without hitting the browsers limit on concurrent requests. Non-web based clients without this limitation can request tiles from a single domain, or all domains, as they choose.

GetFeatureInfo

The recommended way of retrieving information about a specific latitude and longitude is using the WMTS 'GetFeatureInfo' request. This can return data in HTML or JSON formats as desired. The WMTS specification has more detailed instructions on composing a GetFeatureInfo request.