National Data Buoy Center Ian Sears National Data Buoy Center An Overview of Quality Control Procedures for Buoy Data at the National Oceanic and Atmospheric Administration’s National Data Buoy Center (NDBC).

National Data Buoy Center Topics NDBC system and sensor background Automated near real-time quality control Man-Machine mix quality control Pre-archive quality control Planned improvements to quality control process

National Data Buoy Center Introduction NDBC platforms –105 moored buoys –55 Coastal Marine Automated Network (C-MAN) Partner –235 Integrated Ocean Observing System (IOOS) –181 National Ocean Service (NOS)

National Data Buoy Center Introduction NDBC Quality Control –Near real time application of algorithms –Manual look at all data using. (Tabular data and plots) –Monthly check before archival Partner Platform Quality Control –No monthly check/no archival

National Data Buoy Center NDBC system and sensor background 3 meter discus buoy 6 meter NOMAD buoy 10 & 12 meter discus buoy C-MAN

National Data Buoy Center Typical Buoys

National Data Buoy Center Typical C-MAN

National Data Buoy Center 3-meter Staple of Coastal locations. Aluminum hull Meteorological parameters Directional wave capability Ocean parameters Platform descriptions 6-meter Built for survivability Aluminum hull Meteorological parameters No Directional wave capability Ocean parameters 10 & 12 meter Must be towed to location. Steel hull Meteorological parameters Directional wave capability Ocean parameters Capsize in seas > 10m. C-MAN Docks, piers, light houses. Meteorological parameters No Directional wave capability Ocean parameters

National Data Buoy Center Partner Stations (May 2006)

National Data Buoy Center How We Get the Data NDBC data –Geostationary Environmental Operational Satellite (GOES) –Iridium Partner data –Providers send WMO or XML message to NDBC ftp account (most providers use this method) –Process raw GOES messages at the NWSTG –NDBC pulls data from provider’s server in native format and translates to XML (NOS NWLON) –NDBC pulls data from partner database using web services and translates to XML

National Data Buoy Center NDBC Data Quality How? –Evaluate new systems and sensors –Calibrate every sensor –Evaluate data during service visits –Near Real-time automated validation –Next day man-machine mix, 24x7 coverage –End of month man-machine mix archival.

National Data Buoy Center Automated QC in near real-time Data arrive on two redundant computers at the National Weather Service Telecommunications Gateway. Data are checked for truncations to messages and parity errors in transmissions. Data are checked against algorithms and flagged if necessary. Only validated data are packaged and sent to end users. All data, including flagged data, are sent to NDBC. Instructions are given on release status of data.

National Data Buoy Center QC flags Hard flags –Identified by capital letter –Clearly degraded data –Data not released to public Soft flags –Identified by lowercase letter –Questionable data –Human data analyst notified of questionable data –Data released to public (flags not included)

National Data Buoy Center Man Machine mix Conducted with in 24 hours of receipt of data Data analyzed in tabular form –Hard flagged data has red text –Soft flagged data has yellow text Data analyzed in graphical form complete with flags.

National Data Buoy Center

Archive Beginning of each month Senior data analyst checks prior month’s data using graphical aids. Removes erroneous data prior to archive

National Data Buoy Center Planned improvements Presently working on a scored QC algorithm NDBC technical support contractors working to streamline time series plots. Incorporate the same sophistication in QC for oceanographic data