Michael O. Gonsalves, LTJG/NOAA Dean J. Battilana, LEUT/RAN A study in the implementation of a tilted multibeam transducer in an ultra-shallow riverine environment Shallow Survey 2008, Portsmouth NH Token commento Michael O. Gonsalves, LTJG/NOAA Dean J. Battilana, LEUT/RAN University of Southern Mississippi – Summer Survey 2008

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Presentation Overview Survey Background… Tilted Mount – Increased swath width… Tilted Mount – Data further inshore… Total Propogated Uncertainty… CUBE Filtering Regime… Conclusions…

University of Southern Miss. Survey Area Pearl River, LA/MS Port Bienville Industrial Complex University of Southern Miss. Ultra Shallow…

Available Platforms Open Skiff Draft – 0.30m Knudson SBES LeMoyne Imagenex DeltaT

An opportunity for improvement…

Usable Swath Width vs. Depth

Swath Width vs. Spot Spacing Anticipated Survey Conditions

Percent Gains vs. Traditional Mount Can survey to 12m without loss

Tilted mount facilitating inshore acquisition TD = 1.0m α = 5-deg DS = 11.4m

Tilted mount facilitating inshore acquisition SB Draft – 0.3m MB Draft – 1.0m

Tilted mount facilitating inshore acquisition (cultural features vs Tilted mount facilitating inshore acquisition (cultural features vs. sloping beach)

An increased swath…

Total Propogated Uncertainty *beep* *boop*

Total Propogated Uncertainty

Outerbeam Noise Noisy outerbeams resulting from a truncated receive time… …where outer-fluff is at a constant range…

Total Propogated Uncertainty

Processing Pipeline I CARIS HIPS FLEDERMAUS PFM Direct Convert Data Apply Tide & SV Calculate TPU PFM Direct Create CUBE surface Build PFM from HDCS

Total Propogated Uncertainty & CUBE

Processing Pipeline II CARIS HIPS FLEDERMAUS Convert Data Apply Tide & SV Calculate TPU PFM Direct Create CUBE surface Build PFM from HDCS Edit Hypotheses Filter Soundings

Hypotheses Editing Paradigm

Hypotheses Editing Paradigm

Processing Pipeline III CARIS HIPS FLEDERMAUS Convert Data Apply Tide & SV Calculate TPU PFM Direct Create CUBE surface Edit Hypotheses Build PFM from HDCS Apply edits to HDCS Quality Control Final Cleaning Filter Soundings

Final Cleaned Data & Surfaces…

Final Cleaned Data & Surfaces…

Crossline Check – IHO Order

Questions? Conclusions With proper planning a high-accuracy survey can be conducted with a tilted mount by quantifying: Depth Ranges Desired Resolution Desired Distance from shore Increased outerbeam noise can be handled with a proper filtering scheme Questions?