OPeNDAP CODAR Combining Server Provide CODAR surface current vectors in response to request for data within a user-specified region and time range. Will make use of NOAA radial data node located at Rutgers. oRadial server and combiner will run on computer with access to data on node. Combining of radials using least-squares technique. Modes of operation: oArchiving mode - run at regular intervals with vector fields archived. oDemand mode - run in response to specific user request. oSpecialized user (e.g. modeler) could request radials directly. D. Ullman (URI) D. Holloway (OPeNDAP)

OPeNDAP Combiner System Schematic Radial Servers (Data Providers) Site 1 … Site 2Site 3Site N Radial Request (sites, time range) Radials (lon, lat, radial direction, magnitude) Aggregation Server Vector Request (lon, lat, time ranges, optionally: grid, averaging radius) OPeNDAP Client Current Vectors (t, lon, lat, u, v, Δu, Δv) Determines sites needed Combining of radials

OPeNDAP Combiner System Schematic Radial Server Radial Node Radial Request (sites, time range) Radials (lon, lat, radial direction, magnitude) Aggregation Server Vector Request (lon, lat, time ranges, optionally: grid, averaging radius) OPeNDAP Client Current Vectors (t, lon, lat, u, v, Δu, Δv) Determines sites needed Combining of radials With NOAA radial archiving, now need only 1 radial server.

OPeNDAP CODAR Combining Server Progress Purchased computer to interface with NOAA radial node. Addressed issues of server capability and performance: 1.Radial server needs to handle multiple radial formats. 2.Want user capability to specify locations (grid) where current vectors computed and as well as averaging radius. 3.Provide several uncertainty measures: Case where radial uncertainties unknown or poorly characterized (present state of affairs). Case where radial uncertainties provided (future?). Output data will be structured as netcdf.

OPeNDAP CODAR Combining Server Plans By end of year 1: Server installed and providing current vectors for MARCOOS region.