FRONT

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LISICOS LONG ISLAND SOUND INTEGRATED COASTAL
OBSERVATORY
FRONT
An Experimental Coastal Observatory
Monitoring Your Sound
Moored Array
CODAR
Surface Salinity
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CODAR in SAR
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The SAR Problem

• NOAA tidal current predictions are spatially
  limited, and dont include wind currents.
• TWC fields are needed from time of incident to
  2-6 hours into the future.
• DMBs SLDMBs dont provide all these times
• Therefore, Non-optimal large Search Areas

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FRONTCODAR Region
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Short Term Prediction System (STPS)

• Need to cover the time from of availability of
  CODAR (-2 hours) to end of search time (6 hours)
  
• A Statistical Data-based Algorithm Is
  Transferable and relatively Inexpensive
• Currents are Separated into Tidal and Residual
  (Wind) portions

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SLDMB Trajectories

• Drifting Particles Can Be Tracked If the Velocity
  Field Is Known
• The Velocity Distribution Is Often Complicated

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Example Time Series
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The STPS Approach

• Currents Can Be Separated into Tidal and Residual
  (Low Frequency) Parts
• Tides Are Easy to Predict (Harmonic Analysis)
• The Residuals Are Difficult
• Gauss-Markov Estimation

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STPS Error vs Time

• Mean RMS Error in Velocity vs Time Since
  Prediction

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SLDMB Deployments

• BIS Region
• Dec 02
• March 03
• NJ Shelf Region
• March 03

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BIS SLDMB Trajectory
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24-Hour SLDMB Trajectories

• Black Actual SLDMB Trajectory
• Red Trajectory Predicted From NOAA Data
• Blue Trajectory Predicted From CODAR Data

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BIS Final Position Error
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NJ Shelf Final Position Error
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BIS 95th Percentile Separation
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NJ Shelf 95th Percentile Separation
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CODAR Based Prediction Uncertainty

• Use Observed CODAR
• 100 Trials
• 20 cm/s Error Assumed in U and V
• Box Encloses All Final Positions.

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CODAR Based Prediction Uncertainty

• Use Observed CODAR
• 100 Trials
• 20 cm/s Error Assumed in U and V
• Box Encloses All Final Positions.

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Success Rate
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Next Steps

• Develop Better Understanding of Errors
• Improve Data Product Accuracy
• Understand Impact on Search Area Determination
• Integrate Wind Data to Improve STPS Algorithm
• Add NEOS Interface to Website
• Develop Process for Data Aggregation Suitable to
  Support Further Analysis and Intended End Use
• Determine Operational Impact and Evaluate Utility
  to Coast Guard

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BIS Error Contributions