IN-SITU WAVE GROUP

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IN-SITU WAVE GROUP
Kent Hathaway, Moderator QARTOD IIFebruary
28 March 2, 2005
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Sensor selection

• Datawell buoy QC chosen as example of a process
  to establish a QA/QC recipe
• Our group will compile recipes for other sensors
  prior to QARTOD II publication

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What is a Datawell buoy?

• Spherical
• Directional
• Mooring connected by bungee cord.
• Surface following, with vertical accelerometer,
  compass, pitch and roll
  sensors
• Vertical motion not susceptible to the pitch
• No limitation on depth
• Sophisticated processing inside
• Protective triangle- protects from spinning
  during ship collisions.

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1. What real-time quality control tests should
be applied?

• Datawell transmits both an XYZ file and a
  spectral file
• Frequency domain
• Check Factors Test ratio of vertical to
  horizontal displacement
• Inclination Test
• Period exceedence Test
• Threshold Test- Hs, Tp, Dp, (SNR, Hrms, Tm, Dm)
• Time Domain
• Spikes, flat episodes, range, consecutive values,
  acceleration, mean test
• Quality of Telemetery
• Discontinuities in transmission
• Data Corruption - CRC

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2. What categories of real-time quality
descriptor flags should be required?

• Datawell uses own flag system, but these can be
  mapped to agree with QARTOD I system
• -9 missing
• 0 quality not evaluated
• 1 bad
• 2questionable/suspect
• 3 passed real-time QA/QC (as opposed to GOOD)
• Distinction should be made between real-time
  flags and post-processing flags
• Flags should be defined in metadata

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3. What real-time metadata descriptors should be
included?

• Providers should stay attuned to the IOOS/DMAC
  evolution
• Providers should work towards making headers
  available in FGDC compliant format on request
• Examples of datawell headers are listed on pages
  58-61 of QARTOD I Report
• Will work with metadata initiative group to
  define header parameters.

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4. What real-time calibration flags should be
required?

• Buoy is calibrated at manufacturer prior to
  purchase. Data provider should include
  calibration date and method, as defined by
  manufacturer, in metadata.
• Pre-deployment verification (prior to each
  deployment)
• bounce
• compass
• inclination
• electronic checks
• In situ verification (parameters returned with
  each data stream)
• check factor
• inclination

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5. What common data formats should be required?

• Datawell output permits mapping to any desired
  data format
• ASCII or binary
• NetCDF
• compressed
• FM-13 and FM-65
• others

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6. Additional requirements associated with DMAC?

• Data providers should
• keep apprised of DMAC evolution
• prepare to deliver dynamic data service based
  upon further specifications by DMAC
• provide guidance to DMAC regarding transport
  protocols and formats for data transfer???

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Describe key next steps and current roadblocks to
developing and implementing an operational QA/QC
capability.

• Roadblocks
• Lack of specifics in DMAC
• Capacity for verification procedures among
  certain users
• Developing QA/QC capability takes time and
  experience
• Need standardization of XML tags
• Data transport between regional organizations

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Next steps

• Undergo same exercise for other wave sensors such
  as pressure gauges, buoys, ADCPs, radar, HF
• Email draft recipe and list of metadata
  parameters to rest of group to get feedback
• Assemble matrix using this feedback

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Questions?