WIS2 Overview
WMO Information System 2.0 has been designed to meet the shortfalls of the current WIS and GTS, support the WMO’s Unified Data Policy and the Global Basic Observing Network (GBON), and meet the demand for high data volume, variety, velocity, and veracity.
WIS 2.0 uses the public internet (rather than private dedicated links as for GTS) and uses a "publish-subscribe" pattern where users subscribe to a topic to receive new data in real-time using the MQTT protocol.
Each Data Provider is required to host a WIS 2.0 node that sends WIS 2.0 data notifications and WIS 2.0 metadata notifications and enables the download of data over HTTP.
WIS2 Global Services
Three types of Global Services are used to enable the dissemination of data in the WIS2 network:
- Global Broker: Globally accessible MQTT Broker that re-publishes data-notifications of all WIS 2.0 Nodes. The users of WIS 2.0 will be able to access data in real-time by subscribing to a Global Broker and receiving notifications when new data are available for download from a Global Cache or from the data provider.
- Global Discovery Catalogue: Globally accessible catalogue, hosted on HTTP, storing WIS 2.0 Discovery Metadata records. The Global Discovery Catalogue allows users to discover the available datasets on WIS 2.0 and provide information on how and where to access the data.
- Global Cache: Globally accessible HTTP-endpoint where data classified as core can be downloaded from
A Data Consumer in WIS 2.0 can discover the MQTT-endpoints for subscribing to data using Global Discovery Catalogue. Data classified as "core" by the Unified Data Policy will be available for download without access restrictions from the Global Cache. For "recommended data" a Data Consumer is required to access the WIS 2.0 of the data provider, and access restrictions may be applied.
WIS 2.0 Topic Hierarchy
Data Consumers subscribe to specific WIS2 topics to target the data-type they wish to receive.
The topic structure is organized according to Annex 1 of the Unified Data Policy to make it easy to find the topic associated with the relevant data-type:
For more information see WIS2 Topic Hierarchy (draft)
WIS 2.0 Notification
The WIS 2.0 Notification standard defines the attributes used in the message payload of a WIS2 Notification.
A WIS 2.0 Notification contains a "canonical" link indicating the HTTP-endpoint where the data can be downloaded from :
Data published on "origin/a/wis2/<centre-id>/data/core" can not implement access control and the canonical link should be available for download by the WIS2 Global Caches.
For data published "origin/a/wis2/<centre-id>/data/recommended" access control may be implemented. Data published on this subtopic will never be downloaded by WIS2 Global Caches.
WIS 2.0 Metadata
WIS 2.0 Discovery Metadata records are encoded according using the WMO Core Metadata Profile (WCMP) standard.
Data Producers are required to publish a WIS 2.0 Notification on the topic "origin/a/wis2/<centre-id>/metadata" of their WIS2-node, containing a canonical link to the WCMP2 record. The Global Discovery Catalogue is updated using the records published on this "metadata" subtopic.
Setting up a WIS 2.0 Node
In order to setup a WIS 2.0 Node for data sharing on WIS2.0, the Data Provider needs to setup the following components to be accessible over the public internet:
- MQTT-broker publishing WIS2 Notifications for data and metadata
- HTTP-endpoint for downloading the data advertised in the notifications
These components may be provided by commercially developed weather data sharing solutions or can be developed as custom solutions by a Data Provider.
In order to accelerate the implementation of WIS2, WMO has enabled the development of the "WIS2-in-a-box" (wis2box) software: a Free and Open Source (FOSS) Reference Implementation of a WIS2 Node. For more information see the wis2box documentation.
Implementation plan and transition
For more information see WIS2 Implementation plan and GTS-to-WIS2 transition