qa/qc of ocean currents

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QA/QC of Ocean Currents. Bill Burnett NOAA/NWS National Data Buoy Center Stennis Space Center, MS 27 February 2008. Currents Working Group. - PowerPoint PPT Presentation

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  • QA/QC of Ocean Currents Bill Burnett NOAA/NWS National Data Buoy CenterStennis Space Center, MS

    27 February 2008

  • Currents Working GroupThe first workshop (QARTOD I) was held at the NOAA National Data Buoy Center (NDBC) office at the Stennis Space Center, MS in the winter of 2003. Over 80 participants attended with the primary task to develop minimum standards for calibration, QA/QC methods and metadata http://nautilus.baruch.sc.edu/twiki/pub/Main/WebHome/QARTOD_final_09.pdfQARTOD II was held February 28-March 2, 2005 in Norfolk, VA. This workshop focused on wave and current measurements and thier unique calibration, metadata and QA/QC needs. http://nautilus.baruch.sc.edu/twiki/pub/Main/WebHome/QartodIIFinal.docQARTOD III was held at Scripps Institution of Oceanography, La Jolla, CA on November 2-4, 2005. It addressed QC for CTDs, in-situ currents, remote currents and waves. http://nautilus.baruch.sc.edu/twiki/bin/view/Main/Qartod3PresentationsQARTOD IV was held at Woods Hole Oceanographic Institution on June 21-23, 2006. The meeting was held to approve Quality Control standards developed in QARTOD I III, and begin focusing on Quality Assurance standards.

  • Current Profiler Bridle-mountCage-mountBuoy-mountAdditional Current ProfilersAttached to C-MAN or ATON stationsBottom-mountedSingle Point Current MetersCurrents Strategy

  • Current Technologies

  • External Hull Mounts37SM CTD SensorExternal ADCP Battery Canisters (2) with Retainer Bracket

  • NDBC MMS PageApply quality control to real-time ADCP data from deep-water oil platforms and rigs

  • Surface Current PlotsOnslow BayInside BuoyEast ofVirginia Beach

  • Surface Current PlotsLake Huron

  • Celtic Sea and Transocean Marianas Inertial Currents and Current

  • Endeavour and Na KikaNear-Inertial Currents

  • Matterhorn and BoomvangPassing Eddies

  • Thunderhorse Currents

  • Ocean Star and DD-1 Currents

  • Max Smith Currents

  • Na Kika Bottom MountedDelayed-Mode Data

  • Data QualityPurpose: Remove gross errors Data rejected: Virtually certain to degrade productsTypical causes: Transmission errors, power degradations, broken cablesLimitations: Wont detect minor errors, biases

  • Data Quality

    Limit check Are the currents within standard data limits? Time continuity check Vertical velocity relational check The limit and time continuity checks are applied to each velocity measurement The vertical-velocity-relational check deletes horizontal current measurements when the corresponding absolute value of the vertical velocity is too high to be physically reasonable.

  • Teledyne RD Instruments ADCP QUALITY CONTROL SHEETSPassSuspectFailLevel 1 - Red (required)Bit status (Built In Test) - diagnosticsBIT result is zeroBIT result is non-zeroBIT result is NAEcho amplitude/intensityvalue between 70 and 220 countsvalues between 60 and 70 countsvalues greater than 220 counts; values less than 60 countsPitch/Roll (absolute value)0-15 deg15-20 deg>20deg Heading0-360 degrate of change greater than 5 degrees for ens to ens>359.9deg or negativePitch/Roll (delta)1 deg diff from one ens to next ens>5 deg diff from one ens to the next

  • Teledyne RD Instruments ADCP QUALITY CONTROL SHEETSPassSuspectFailLevel 1 - Red (required)Vertical VelocityThe difference is less than or equal to 20 cm/s for OO 38 (BB and NB), OS 38, 75 and 150 (BB and NB), WH Long Ranger 75 (BB and NB) and WH QuarterMaster 150 (BB and NB), WH 300, 600 and 1200 kHz (BB and NB)The difference is greater than 20 cm/s and less than or equal to 40cm/s for OO 38 (BB and NB), OS 38, 75 and 150 (BB and NB), WH Long Ranger 75 (BB and NB) and WH QuarterMaster 150 (BB and NB), WH 300, 600 and 1200 kHz (BB and NB)The difference is greater than 40 cm/s for OO 38 (BB and NB), OS 38, 75 and 150 (BB and NB), WH Long Ranger 75 (BB and NB) and WH QuarterMaster 150 (BB and NB), WH 300, 600 and 1200 kHz (BB and NB)

  • Teledyne RD Instruments ADCP QUALITY CONTROL SHEETSPassSuspectFailLevel 1 - Red (required)Correlation Magnitude ThresholdsAt least 3 of the 4 correlation magnitude values for each bin are greater than or equal to 115 for WH Long Ranger 75 kHz (BB and NB), WH QuarterMaster 150 (BB and NB), WH 300, 600 and 1200 kHz (BB and NB): At least 3 of the 4 correlation magnitude values for the bin are greater than or equal to 130 for OO 38 BB, OS 38, 75 and 150 BB or greater than or equal to 170 for OO 38 NB, OS 38, 75 and 150 NBAt least 3 of the 4 correlation magnitude values for each bin are less than 115 and greater than or equal to 64 for WH Long Ranger 75 kHz (BB and NB), WH QuarterMaster 150 (BB and NB), WH 300, 600 and 1200 kHz (BB and NB): At least 3 of the 4 correlation magnitude values for the bin are less than 130 and greater than or equal to 100 for OO 38 BB, OS 38, 75 and 150 BB or less than 170 and greater than or equal to 110 for OO 38 NB, OS 38, 75 and 150 NBAt least 3 of the 4 correlation magnitude values for each bin are less than 64 for WH Long Ranger 75 kHz (BB and NB), WH QuarterMaster 150 (BB and NB), WH 300, 600 and 1200 kHz (BB and NB): At least 3 of the 4 correlation magnitude values for the bin are less than 100 for OO 38 BB, OS 38, 75 and 150 BB or less than 110 for OO 38 NB, OS 38, 75 and 150 NB

  • Teledyne RD Instruments ADCP QUALITY CONTROL SHEETSPassSuspectFailLevel 1 - Red (required)Error velocity - four beam disagreement indicatorError velocity in each bin is less than or equal to 15 cm/sError velocity in each bin is greater than 15 cms/s and less than or equal to 30 cm/s or equals -32678Error velocity for each bin exceeds 30 cm/sLevel 2 Yellow (recommended)Battery voltage (V1 & V2) two batteries36 - 48 volts30 - 36 volts< 30 voltsWater temperatureChange in 0.25 degree C in 6 minutes>50degC or range of sensorTimestampstuck time or future timeSpeed of sound (derived)>1600m/s or 70%>30% or

  • Teledyne RD Instruments ADCP QUALITY CONTROL SHEETSPassSuspectFailPercent solutions - number of beams usedThe above values for each bin are flagged as goodThe above values for each bin flagged as suspect or failed for less fewer than 50% of the binsThe above values for each bin are flagged as suspect or failed for greater than or equal to 50% of the binsPercent good pings (PGP)Workhorse Long Range 75 kHz: Total percent good pings is greater than 10%. Ocean Observer 38 kHz: Total percent good pings is greater than 25%Workhorse Long Range 75 kHz: Total percent good pings is greater than or equal to 5% and less than 10%. Ocean Observer 38 kHz: Total percent good pings is greater than or equal to 22% and less than 25%.Workhorse Long Range 75 kHz: Total percent good pings is less than 5%. Ocean Observer 38 kHz: Total percent good pings is less than 22%

  • Real-Time Quality Descriptor FlagsCategories agree with QARTOD I recommendations:-9 = missing value0 = quality not evaluated1= bad2=questionable/suspect3=good

  • Questions?See the data sheets at:

    http://ioosdmac.fedworx.org

    Contact Info:Bill BurnettDMAC Branch ChiefNational Data Buoy CenterStennis Space Center, MS 39529Bill.Burnett@noaa.gov228-688-4766