Authors: HEFFRON Erin 1, DOUCET Maurice 1, GEE Lindsay 1, WEBER Tom 2, MAYER Larry 2 and BEAUDOIN Jonathon 2

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1 Title: What s the Difference? A Comparison of Water Column Data to Bathymetry From the Sonar Bottom Detection in the Shallow Survey 2012 Common Dataset Authors: HEFFRON Erin 1, DOUCET Maurice 1, GEE Lindsay 1, WEBER Tom 2, MAYER Larry 2 and BEAUDOIN Jonathon 2 1. IVS 3D Inc., 104 Congress Street, Portsmouth NH, USA 2. Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM- JHC), University of New Hampshire, 24 Colovos Road, Durham NH, USA The very latest multibeam sonars have the capability to record the sonar returns throughout the entire ping for each beam, mapping the water column along with the seafloor. This capability opens up new potential uses for multibeam sonars, including the direct mapping of fish and marine mammals, the mapping of natural plumes and vents, the location of midwater targets, and if water column properties are appropriate, a wide range of physical oceanographic processes. Though mid-water capable sonars have been available for several years, there has up until recently been very few ways to view and further utilize this data outside of the initial 2D view during acquisition. In 2009, IVS 3D released FMMidwater, a commercial off-the-shelf module for post-processing and visualizing water column data. This software, developed in conjunction with researchers at the Center for Coastal & Ocean Mapping, University of New Hampshire, provides a tool to finally make use of this new data type, fuse it with bathymetry and other available data, and visualize it in an intuitive manner. For the first time, some of the sonar manufacturers have recorded water column data during the Shallow Survey data acquisition phase and have provided water column data in addition to the normal bottom-detected bathymetry as part of the Common Dataset. This presentation will investigate the differences between the water column data and the bottom-detected bathymetry as provided by each sonar manufacturer, and discuss potential uses for this type of data in various fields such as hydrographic survey, resource exploration, and marine habitat mapping.

2 What s the Difference? A Comparison of Water Column Data to Bathymetry From the Sonar Bottom Detection in the Shallow Survey 2012 Common Dataset Erin Heffron 1, Maurice Doucet 1, Lindsay Gee 1, Tom Weber 2, Larry Mayer 2, and Jonathon Beaudoin 2 1. QPS US, Portsmouth NH, USA; 2. Center for Coastal and Ocean Mapping/Joint Hydrographic Center, University of New Hampshire, Durham NH USA

3 Additional Acknowledgements Josh Grava and Jon Marcus, Reson Jan Haug Kristensen, Kongsberg Maritime

4 Overview Brief history of MBES watercolumn data Background and description of FMMidwater Data Comparisons HMSNZ South Seas (Compulsory Area 1) Fresh water seeps, Hutts River Mouth (Optional Area 6) Potential uses

5 Background: Multibeam Sonars and the Water Column : Simrad SM : 3D Visualization

6 Background: Multibeam Sonars and the Water Column : Kongsberg EM : Reson SeaBat 7000 Series, ? R2Sonic - Very few commercial tools available for reading, processing, imaging, visualizing this data after collection - Researchers writing their own tools for processing and/or visualizing

7 FMMidwater: Background - GOAL: Provide easy to use tool to actually USE water column data, across MANY applications : IVS 3D supported CCOM to develop and commercialize software for working with water column data - April 2010: FMMidwater beta being used during Deep Water Horizon and on other research projects - August 2010: IVS 3D releases FMMidwater as part of the Fledermaus Suite 7.2 release

8 FMMidwater

9 FMMidwater Range Solution (Bottom Detect) NOT the Range Solution

10 FMMidwater Stuff!

11 FMMidwater Fan Curtain ASCII Refracted Points ASCII Points

12 Data Comparison: Location

13 Compulsory Area 1: HMSNZ South Seas - Water column data - Kongsberg EM 2040.wcd (water column) and.all (navigation) - Reson 7125.s7k (water column and navigation) - Bathymetry - Kongsberg EM Reson R2Sonic - Imagery: LINZ

14 South Seas: Features from Bottom Detect Shoal Davit Triangles

15 South Seas: Features from Bottom Detect Various Bridge/Gun Features

16 South Seas: Features from Water Column - Kongsberg Bridge/Gun Triangles Davit?

17 South Seas: Features from Water Column - Kongsberg

18 South Seas: Features from Water Column - Reson Davit? Bridge/Gun Target Triangles Target

19 South Seas: Kongsberg Water Column vs. Bottom Detect Ping 204 Ping 206 Pings 244, 247, 248, 249

20 Kongsberg Kongsberg South Seas: Reson Water Column

21 Optional Area 6: Hutt River Fresh Water Seeps - Water column data - Kongsberg EM 2040.wcd (water column) and.all (navigation) north and south - Bathymetry - Kongsberg EM 2040 north and south - Reson south - R2Sonic north - Imagery: LINZ

22 Water Column Features - North Line 16 Line 24

23 Water Column Features: Kongsberg EM2040 Line 16 Line 24

24 Water Column Features: R2 Sonic 2024 Line 24 Line 16

25 Fresh Water Seeps - North

26 Water Column Features - North

27 Water Column Features - South

28 Water Column Features - South

29 Applications for Water Column Data Detection and mapping of gas seeps

30 Applications Extraction of additional data to append the bottom detect data (least depth on wreck, confirmation of features)

31 Applications Additional features/details for archeological purposes

32 Applications Soft target applications

33 Summary Hard target features and a few water column targets were visible in both water column and bottom detect, however more detail, more points in water column. Absolute difference comparison would nice Most soft targets (seeps, fish, kelp, etc.) only visible in the water column. Nice to have water column data as part of the Shallow Survey dataset, thanks especially to Kongsberg for providing so much of it!

34 QUESTIONS