U.S. Department of the Interior U.S. Geological Survey Shallow Water Hydrographic Surveying using a High Resolution Multibeam Echosounder Richard C. Wilson, P.E., and Brenda K. Woodward Nebraska Water Science Center 2010 Tri-Agency Meeting Oct. 5, 2010

Hydrographic Surveying Aristotle observed that sound could be heard in water Allies invent the sonar during World War I Coast and Geodetic Survey deployed the Fathometer in 1925 U.S. Navy deployed a multibeam echosounder in the 1960s

Hydrographic Surveying - Purposes Navigational aide Quantity surveys Inspections of dams, bridges, and water control structures Habitat assessments Hydrodynamic and sediment-transport models Geomorphic assessments

Single-Beam Echosounder

Multibeam Hydrographic Surveying Wide yet narrow swath perpendicular to the boat direction Multiple beams in just one ping SURVEYS the ENTIRE RIVER or LAKE BED

Shallow Water Multibeam Hydrographic Surveying Minimum depth is 1 meter Swath angle 128° or width-to-depth ratio 3.5 to 1 Rotation of the transducer for surveying horizontal features Use Single and Multibeam Echosounders, together Flat keel boat Obstructions

Multibeam Echosounder

RESON Seabat 7125 Multibeam Echosounder System Digital beam-former 400 kHz 256 or 512 beams 128° swath angle 200 meter range Bathymetry data and Side-Scan imagery

Multibeam Echosounder Components Projector Array Receiver Array Sound Velocity Probe

Multibeam Echosounder Components Real-Time Kinematic Global Positioning System (RTKGPS) or Differential Global Positioning System (DGPS) Inertial Measurement Unit (IMU) Navigation computer Position and Orientation Solution (POS-MV) motion control unit 7-P sonar signal processor Sonar display

Patch Test Calibration Roll correction Pitch correction Yaw correction Nadar Beam

Collapsed Historical Bridge Deck near Warsaw, Missouri

Bridge Piers near Warsaw, Missouri

Bridge Pier near Warsaw, Missouri

Multibeam Data Processing Dell Precision T7500 Intel Xeon Quad Core Processor 3.46 GHz 12GB DDR3 SDRAM, 1333MHz, 2 GeForce GTX Graphics Card

Multibeam Data Processing Line-by-line swath editing is necessary

Multibeam Data Processing

Gavins Point Dam Multibeam Survey Purpose: Document change from Verify the integrity of energy dissipation structures Create updated bathymetric contours

Gavins Point Dam Spillway

Energy Dissipation Structures Determined the structural integrity Divers were not needed, eliminating a safety hazard Measured change to 0.1 M

Gavins Point Dam - Spillway Intake

Missouri River Bends Missouri River Habitat Assessment and Monitoring Program (HAMP) Habitat improvement through structure modification Wing dike notches Chevrons Parallel dikes Revetment removal

Hydrographic Surveys of Glovers Bend Single-beam echosounder Glovers Bend, Missouri River 2007

Hydrographic Surveys of Glovers Bend Multibeam echosounder Glovers Bend, Missouri River 2009

Hydrodynamic Modeling of the Missouri River using MD_SWMS

Experimental Advanced Airborne Research LiDAR (EAARL) Water penetrating LiDAR Uses Blue-green laser NASA/USGS Technology Shallow water EAARL survey, Central Platte River

Side-Scan Sonar: Using Backscatter Intensity to Classify Substrate

Robert B. Swanson Director (402) Richard C. Wilson, P.E. Associate Director of Hydrologic Studies (402) Ronald B. Zelt Associate Director of NAWQA Studies (402) Jason M. Lambrecht Associate Director of Hydrologic Data (402) CONTACT INFORMATION: Rick Wilson USGS Nebraska Water Science Center (402) South 19 th St. Lincoln, NE http://ne.water.usgs.govhttp://ne.water.usgs.gov