Advances in Hydrographic Surveying Equipment and TechniquesTechniquesBY PAT SANDERS, TECHNICAL DIRECTOR

HYPACK - YSI

Multibeam Sonar: Water Column Data

Water column data is the acoustic time series of every beam for every ping

of your multibeam system.

Water column: Real Time Visualization

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Typical data rates can be 2Gb/Minute!

Logging Water Column Data

If you log WC data all day, in a ten hour day you’ll have 1.2 Terabytes.

(Crazy person option…)

In HYSWEEP SURVEY, you can buffer the WC history. When you see

an interesting feature, you can tell it to begin logging. It will log the

buffered data and all subsequent WC data until you tell it to stop

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buffered data and all subsequent WC data until you tell it to stop

logging.

Time

WC Buffer WC Data

Start

Logging

WC

End

Logging

WC

Logged to file

Editing Water Column Data

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A Water Column Data window in MBMAX-64 (HYPACK Multibeam Editor)

shows the bottom detection points (one per beam) superimposed with the

acoustic time series info.

Editing Water Column Data

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Here, we have manually digitized the vertical wall.

Editing Water Column Data

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Here, we have manually digitized the pilings and

bottom. We are still limited to one detection per

beam! That is where Multi-Detect comes into play.

Multibeam Multi-Detection

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Some MB systems are capable of “Multi-Detection” with more than one point per

beam. This is useful for objects in the water column (anchor lines, gas bubbles,

etc.) and for determining the minimum depth above wrecks.

Multi-Detect MB Data

1st Return

2nd Return

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2nd Return

3rd Return

CLOUD window of multiple pings, all returns.

HYSWEEP can record up to 5 detections per beam. While editing the user can color-code the returns by depth or by return number.

Good: More detail over wrecks and objects in the water column that would normally be missed.

Bad: A lot more noise to be removed.

Multi-Detect Examples

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Multi-detection-OFF Multi-detection ON

Multi-Detect Examples

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Multi-detection-OFF Multi-detection ON

Wobble: The ability to address time delays or mounting errors in your MB data

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The original data (left) has a time offset between the MB and the MRU.

Using Wobble-64 (right), you can adjust the time delay and save the data!

Wobble-64 in HYSWEEP’s MBMAX

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Remote Viewing and Control of Survey Operations Over a Network Connection

SURVEY

Computer

Remote

Computer

LAN

SURVEY

Computer

Remote

Computer

WiFi

14AVI

SURVEY

Computer

Remote

Computer

Internet

WebGL : Viewing Survey Operations and 3D Surfaces over the Internet

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Unmanned Surface Vessels (USVs)

USVs offer a cost-effective platform for collecting survey data.

They can be equipped with everything from single beam sonar,

to multibeam, to side scan!

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AVI

A typical USV. This one is run by NOAA and has RTK GPS, and a single beam echosounder. Total length < 2m.

Controlling the HYPACK SURVEY program remotely with Remote View Over Web. Data is logged onboard the USV.

Watching on a cell phone 500 miles away!

Unmanned Aerial Vehicles (UAVs)

SBG Eclipse D Inertial-RTK GPS Sensor with Directional Antenna

Velodyne VLP-16

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Velodyne VLP-16

Topo Lidar Laser

HYSWEEP Survey

logging on-board.

AVI

Hydrographers are probably better equipped to make land

measurements using topographic lidar than land surveyors!

Survey platform from Infinite Jib (Canada)