Interoperability Provided By:
Demos and Applications
Implementation of Model Data Interoperability for
US Integrated Ocean Observing System (IOOS)
Introduction
The challenges of stovepiped model access, inability to compare and assess model results, and underutilization of model products drove the joint NOAA/USGS study on model data interoperability led by Dr. Richard Signell.
An observed issue was that ocean grids are not regularly spaced. In fact, many structured grid coastal models (POM, ECOM, ROMS, HYCOM, Delft3D) have curvilinear orthogonal coordinates in the horizontal and stretched terrain and free-surface following vertical coordinates (but could be sigma, s-coordinate, double sigma, sigma over z). CF allows these to be specified in a standard way, allowing the possibility of standard-access to data on the models’ native grid.
Data providers do nothing but put their non-compliant files on their web sites. Standards-expert works with provider to generate NcML that aggregates and standardizes their files (adds metadata, changes incorrect metadata, unions or joins data). Data is served via a variety of services, but OPeNDAP is the only one that supports non-regularly spaced grids. A variety of clients can then be used, all built on NetCDF Java.
NJ Toolkit for Matlab
The NJ Toolkit for Matlab makes it simple to access CF data in Matlab, in which the URI can be local NetCDF, remote NetCDF, NcML, or OpenDAP Data URL. Scientists can use powerful applications that they are already familiar with such as Matlab to perform model analysis and evaluation. Here we are comparing two different model results with data using identical color scales and plot limits. However, the important thing is that the scientist was able to easily access data from two remote models as well as data with a single identical command.
3D visualization of data with IDV
The same THREDDS catalog and URLs can be visualized with other standards-based tools such as the IDV.
Single Point of Access Catalog for Unified Access
GEO-IDE Unified Access Framework Catalog is available here.
Web Mapping Service with ncWMS
We can also generate maps on the fly using NcWMS and Godiva2.
Extract to multiple formats using ERDDAP
Successes
- Existing Unidata technology allowed for standards-based delivery of aggregated geospatial data from native model grids that put little or no effort on the data provider.
- Demonstrated interoperability with 17 THREDDS servers in 11 IOOS Regions
- What did we get?
- Single point of access for regional model results
- Interoperable software
- More eyes on the model results
- More usage of model results
- Faster feedback to modelers
- Improved models
- Increased community support for standards-based access