AWIPS II Extended—Data Delivery Paradigm
To meet the objects of the Data Delivery project, the following types of capabilities were envisioned to be explored and implemented:
• Data registry services will provide a means to publish data sources and metadata information and allow for the introduction of new data services. • Data discovery services will provide for a system that can discover datasets and necessary associated metadata, e.g., Extensible Markup Language (XML) schemas, needed to access those datasets. • “Smart” push/pull technologies that will provide the means to subset the data by user selectable field value, time, space, ensemble member, etc., parameters. Such data set filtering will be done on an ad-hoc user request basis or in a pre-defined way where particular data subsets are known based upon upcoming weather.
The Global Systems Division (GSD) has developed a series of prototypes beginning in April, 2010, in order to implement these capabilities. The prototype systems enable clients to discover datasets by querying one of two registry/repositories (reg/reps) implemented by MIT LL and NOAA (MDL). The information returned from the reg/rep is used by the client to request data from remote data providers that have registered their products and services with the reg/rep. Three types of data can be requested – model data (grids) from Web Coverage Services (WCS) data providers; METAR observations from Web Feature Services (WFS) servers; and MADIS observations from a GSD generated JMBL-MADIS server. Gridded data are displayed on the Common AWIPS Visualization Environment (CAVE) GUI via the Volume Browser, while the observation data are displayed via the CAVE plan-view displays in the form of station plots. The Data Delivery system can handle data in three formats – NetCDF-3, NetCDF-4, JMBL XML, and Weather Information Exchange Model (WXXM). All data are stored in HDF5 for display on CAVE. This extension of AWIPS II capabilities was accomplished by developing EDEX and CAVE plug-ins.