InSitu Currents: Breakout Group Report Out

1
In-Situ CurrentsBreakout Group Report Out
QARTOD IIFebruary 28 March 2, 2005
2
Technology Selection

• 25 participants
• Three technology groups
• Current meters
• ADCPs technology selected by group
• Drifters
• In general, did not want to be vendor specific

3
Recommended Real-Time Quality Control Tests
4
Real-Time Quality Control Checks for Red Level
1

• Pitch/Roll
• UVW Vertical velocity/horizontal velocity
• Echo amplitude/intensity
• Percent solutions
• Percent good pings (PGP)
• Error velocity
• Correlation magnitude
• Surface (or bottom) reflection/ detection
• If information is available with instrument

5
Real-Time Quality Control Checks for Yellow -
Level 2

• Heading
• Bit status (Built In Test)
• Battery voltage (V1 V2) two batteries
• Water temperature
• Pressure
• Timestamp
• Std deviation of speeds
• Transmit current
• Correlation coefficient
• Speed of sound
• If information is available with instrument

6
(No Transcript)
7
Real-Time Quality Descriptor Flags

• Each data record goes out with quality descriptor
  flags
• Group Discussion
• Two principle customer groups
• Customer interested in observation only (e.g.,
  maritime community)
• Ensemble flag linked to release of data
• Customer interested in full record (e.g.,
  academia, oil and gas industry)
• Flags for each hard parameter
• Ensemble flag linked to release of data
• Flags for soft flags, if affordable
• Two data sets
• Real-time observations (only Level 2 and 3 data)
• Archived observations (all data)

8
Real-Time Quality Descriptor Flags

• Categories agree with QARTOD I recommendations
• -9 missing value
• 0 quality not evaluated
• 1 bad
• 2questionable/suspect
• 3good

9
Real-Time Metadata Descriptors

• Group Discussion
• Developed a list of recommended fields to send
  with the real-time observation
• Instrument-level description
• Metadata should be in the header of the record

10
Metadata to be Delivered in Real-Time

• Latitude (with a designator fixed or moving)
• Longitude (with a designator fixed or moving)
• Horizontal datum / reference
• Depth of water
• Depth of instrument
• Vertical datum / reference
• Time (with a designator for time zone, e.g., UTC)
• Data collected at beginning, middle, or end of
  sample
• Compass reference
• Serial number
• Units for data reporting
• Orientation

11
Metadata to be Delivered if Affordable

• Sensor type
• Deployment date
• Calibration procedures
• Date of calibration
• System frequency
• Bin size
• Number of bins
• Sampling interval
• Bad beam indicator
• Average interval
• Pings per ensemble
• Compass update rate
• Quality checks descriptions and thresholds
• Blanking distance
• Coordinate system for velocity measurements
• Joyce parameters
• Platform description, including fixed or moving

12
Real-Time Calibration Flags Descriptors

• Place reference to date of calibration in metadata

13
Common Data Formats

• Group Discussion
• Many data formats represented in group
• ASCII is universally understood
• Future holds sensor sending data in XML
• Moving towards automation and interoperability
• Recommendations
• Community should strive to be DMAC compliant
• Recommended format NetCDF, along with data
  dictionary and convention

14
Next Steps and Roadblocks

• Key Next Steps
• Define thresholds for quality control tests
• Develop open source environment for collaboration
  (e.g., TWiki)
• Define specifications for metadata descriptors
• Roadblocks
• Disparity in requirements for different user
  groups could lead to two or more datasets