1. NextGen Network-Enabled Weather (NNEW) Concepts Aaron Braeckel

2. Representational Concepts GIS Community (OGC) Feature “An abstraction of a real-world phenomenon”. !!! Coverage “A feature that has multiple values for each attribute type” Meteorological Community Gridded Data Regular or *irregular multi-dimensional grids Notable for several shared characteristics (efficiency, re-sampling, etc.) Non-Gridded Data Everything else!

3. Service Mapping WFS WMS WFS Point (PIREPs, METARs) Area (AIR/SIGMETs) Fronts Others? WCS ? Thanks Oliver!

4. Integration

5. Gridded Data Formats Primary IOC products are regularly-spaced grids (including radar and other polar products!) Standards-based options: GML (XML) GRIB 1 GRIB 2 HDF5 (with convention) NetCDF 3 (with convention) NetCDF 4 (with convention) JPEG 2000? Fastest growth in meteorological data volume is with gridded products

6. WCS and Gridded Data Service Provider WCSRI Gridded Data Store (Backing Store) Request (HTTP, XML) Data Consumer System Response

7. WCSRI Backing Store The WCSRI uses the NetCDF Java API for backing store access Can acces many gridded file formats: NetCDF 3 and 4 (with a convention) HDF 4 and 5 GRIB 1 and 2 Gini GeoTIFF NEXRAD Level 2 NIDS/NEXRAD Level 3 McIDAS … To test whether a file is geo-locatable and an interpretable grid, use the most recent version of ToolsUI and open the file in the “Grids” section of the “Feature Types” tabToolsUI

8. GML Very flexible data model Transparent (human-readable) Standard gridded data representations still being tuned Extremely inefficient (CPU and compactness), even with binary/efficient XML techniques Not supported as a backing store format Not supported as a response format

9. GRIB 1 and 2 Undisputed leader in compactness WMO Standard, in heavy use in operational MET Random access can be slow Not always self-describing Relatively restrictive model GRIB 1 and 2 are supported as a backing store format GRIB 2 will be supported as a response format*

10. HDF5 Heavily used within NASA Typically used with a convention for geo-location and further standardization General-purpose format A number of advanced features (parallel I/O, nodes, groups) Has some quirks Used less frequently in meteorological communities Supported as a backing store format Not supported as a response format

11. NetCDF 3 General-purpose N-dimensional format NASA and OGC standard Heavy use within research communities Typically used with a convention for geo-location and further standardization Limited compression (!) Governed with less formality Supported as a backing store format Not supported as a response format

12. NetCDF 4 Nearly identical data model to NetCDF 3 Based off of HDF5, with intentional restrictions Typically used with a convention for geo-location and further standardization Governed with less formality Supported as a backing store format Supported as a response format

13. NetCDF Conventions Large number in use Typically specify a “style” for specifying certain information Climate and Forecast Convention (CF) Most popular NetCDF convention Extends and generalizes several other conventions (COARDS, etc) Covers: Filenames Standard field names Missing data Coordinate reference systems Units (time, horizontal, vertical)

14. NetCDF Conventions Several conventions in active use Typically formally managed Specify a “style” for specifying certain information Climate and Forecast Convention (CF) Most popular NetCDF convention Extends and generalizes several other conventions (COARDS, etc) Covers: Filenames Standard field names Missing data Coordinate reference systems Units (time, horizontal, vertical)

15. CF Example

16. Resources NNEW – https://wiki.ucar.edu/display/NNEWD/NNEW+Dissemination+home+pagehttps://wiki.ucar.edu/display/NNEWD/NNEW+Dissemination+home+page Experimental ADDS – http://weather.aerohttp://weather.aero Operational ADDS – http://adds.aviationweather.govhttp://adds.aviationweather.gov OGC – http://opengeospatial.orghttp://opengeospatial.org NNEW Phase 1 access - https://wiki.ucar.edu/display/NNEWD/NNEW+Phase+1+Access+Information https://wiki.ucar.edu/display/NNEWD/NNEW+Phase+1+Access+Information