La dispensa del Workshop tenuto il 23 giugno 2015 a Fiumicino. * cosa sono i SubBottom Profiler e per quali applicazioni vengono usati * quale tecnologia permette loro di rilevare gli strati dei fondali marini e di acque interne * quali caratteristiche tecniche verificare prima di un acquisto Corso tenuto da Nick Lawrence - sales director - Edgetech. Edgetech è rappresentata in Italia in esclusiva da Codevintec.

1. EdgeTech
Sub‐Bottom Profiler
Training

2. • Introduction to EdgeTech
• Sub‐bottom Profilers
– Sub‐Bottom Profiler Principles
– Sub‐Bottom Profiler Field Operations
– EdgeTech Sub‐Bottom Profiler Systems
– Data Interpretation
– Maintenance and Troubleshooting
Agenda

3. • Industry leader in Underwater Acoustics
• EdgeTech (formerly EG&G Marine Instruments)
– Started in 1966 by Doc Edgerton
• ORE Offshore
– Formed in 1963
• Facilities in Massachusetts and Florida
Common Technologies
Underwater Acoustics
Digital Signal Processing
Introduction to EdgeTech

4. • EG&G started by “Doc” Edgerton
• Called “Papa Flash” by Jacques
Cousteau
• Work on underwater photography
lead into sonar development
Images © Harold & Esther
Edgerton Foundation
Introduction : Who we are

5. • Long history in the marine community
• Diverse offering based on underwater acoustics
– Sonar Systems
• Side Scan Sonars, Bathymetric systems, and Sub‐Bottom Profilers
– Acoustic Command Systems
• Acoustic Releases and Acoustic Actuators
– Acoustic Positioning
• USBL Systems
• Standard Products and custom solutions provider
• Manufacturing quality and efficiency
– Cell based lean manufacturing
– Part traceability
– Rigorous Testing
• Very strong Engineering team
– Research and Development
– Product Applications
– Customer Support and Training
What sets EdgeTech apart ?

6. • Engineering
– Acoustic
• Ceramics, transducers, hydrophones, arrays
• Algorithms
– Mechanical
• High level of experience with electronics, housing, array, packaging, cabling
– Software
• Firmware and user‐level expertise
– Test
– Specials, custom solutions
– New product development emphasis
Core Competencies

7. • Manufacturing
– Cell based lean manufacturing
– Strong supporting test facilities for
engineering and manufacturing
• Pressure chambers, environmental, acoustic
test tank, 2 research vessels for on‐water tests
• Support / Customer Service
– Training and Commissioning Support.
– Phone and Remote Access Support
• 24 hour / 365 days
– Authorised Service Centres
Core Competencies

8. • Sonar Systems
– Side Scan Sonar
– Sub‐bottom Profilers
– Bathymetry
– Combined Systems
– AUV/ROV Systems
• Actuated Products
– Acoustic Releases
– Pop‐up Systems
– Acoustic Actuators
• Navigation & Positioning
– USBL Acoustic Tracking Systems
– Motion Reference Unit (MRU)
Products & Solutions

9. Sonar Systems
4125
Ultra High Resolution
Lightweight Portable
4200
Multipurpose
Side Scan System
6205
Bathymetry &
Side Scan Sonar
LMCS
Military ‐ High Speed &
Long Range
Side Scan Sonar    
Sub‐bottom Profiler
Bathymetry (3‐D) 
Frequency options
available
400 kHz & 900 kHz
600 kHz & 1600 kHz
100 kHz & 400 kHz
100 kHz & 600 kHz
300 kHz & 600 kHz
300 kHz & 900 kHz
230 kHz (230 & 550 kHz SSS)
540 kHz (230 & 550 kHz SSS)
540 kHz (550 & 1600 kHz SSS)
600/1600 kHz MP DF
Depth (meters) 200 m 2000 m 100 m 300 m or custom
Bathymetry : 
Multi‐Pulse option :  
Dynamic Focusing :  
Configurations :
Tow fish   
Ship or pole mount   
AUV/ ROV mount  
Sample Applications: • Hydrographic Surveys
• Geological Surveys
• Search & Recovery
• Channel/Clearance Surveys
• Bridge/Pier/Harbor Wall
Inspection
• Hull Inspections
• Hydrographic Surveys
• Archeological Surveys
• Cable and Pipeline Surveys
• Geohazard Surveys
• Geological/Geophysical Surveys
• Benthic Habitat Mapping
• Dredging Operations
• Military Rapid Environ.
Assessments (REA)
• Nautical Charting
• Route Surveys
• Shallow Water Hydrographic
Surveys
• Mine‐like target detection and
classification
• Change detection
• Q Route Survey
• High speed/long range survey

10. 3100/3200
Portable Sub‐bottom
profiler
2000
Combined Side scan sonar
& Sub‐bottom
2200 / 2205
Sonars for ROV, AUV, USV
2400 / Specials
Deep tows
Side Scan Sonar   
Sub‐bottom Profiler    
Bathymetry (3‐D)  
Frequencies options
available
500 Hz‐12 kHz
2‐16 kHz
4‐24 kHz
500 Hz‐12 kHz
2‐16 kHz
100 kHz/400 kHz
300 kHz/600 kHz
all sub‐bottom, side scan and
bathymetry frequencies available
1‐10 kHz
2‐16 kHz
75 kHz/110 kHz
120 kHz/410 kHz
230 or 540 kHz (bathy)
Depth (meters) 300 m 2000 m, 3000 m options to 6000 m options to 6000 m
Bathymetry: optional
Multi‐Pulse :  
Dynamic Focusing : optional
Configurations :
Tow fish   
Ship or pole mount 
AUV/ ROV mount  
Sample Applications: • Geological Surveys
• Geohazard Surveys
• Buried Object Location
• Mining/Dredging Surveys
• Bridge/Shoreline Scour
Surveys
• Pipeline and Cable Location
• Archeological Surveys
• Geological/Geophysical
Surveys
• Sediment Classification
• Cable and Pipeline Surveys
• Pre/Post Dredging Surveys
• Scour/Erosion Investigation
• Marine Construction Surveys
• Geo‐hazard surveys
• Geological/geophysical surveys
• Buried pipeline and cable
• Route Surveys
• Archeological surveys
• Military surveys
• Deep Water Searches
• Geohazard Surveys
• Geological/Geophysical Surveys
• Cable and Pipeline Surveys
• Route Surveys
• Archeological Surveys
Sonar Systems

11. Example Customers
A far from complete listing:
• Military /
Hydro
– United Kingdom
MOD
– France (SHOM)
– India DSR/NHO
– Canada
– Sweden
– Egypt
– Atlas
– Thales
– Kongsberg
• Commercial
– C&C Technologies
– EGS Asia
– Fugro Survey
– Gardline Surveys
– GSE Rentals (UK)
– NCS Subsea (USA)
– Odyssey Marine
– Subsea
Technology &
Rentals (UK)
– Survey Equipment
Services (USA)
– Watergate
(Nigeria)
• Research
– NOAA (USA)
– Scripps Institute of
Oceanography
(USA)
– CEFAS (UK)
– KORDI (Korea)
– Maritime Institute
(Poland)
– Institute of
Marine Survey
and Planning
(China)
– Geological Survey
of Ireland

12. Sub‐Bottom profiling systems identify and
measure various sediment layers that exist
below the sediment/water interface.
The sound from the transmitter travels down to
the seafloor. Some of the sound reflects off the
seafloor but some of the sound penetrates the
seafloor. The sound that penetrates the seafloor
may also reflect off layers of material within the
seafloor. The reflected sounds travel back up to
the surface.
The time it takes the sound to return to the ship
can be used to find the thickness of the layers in
the seafloor and their position. It also gives
some information about the composition of the
layers.
What is a Sub‐Bottom Profiler

13. • Map, measure and classify sediment layers within the sea floor
– Locate and map possible hazards in the area
• Faults
• Shallow Gas
– Locate and map bedrock
• Locate objects on or in the sea floor
– Determine the depth of burial of an object
• Pipelines
• Cables
• Map natural resources
– Map dredging volumes for clearance
– Map dredging volumes for extraction
Uses of Sub‐bottom Profilers

14. • Seismic Reflection
• Sound Source
• Penetration
• Hydrophones
• Time of Travel
What is a Sub‐Bottom Profiler

15. • Sonar Equations
– Source Level
– Transmission Losses : Spherical Spreading
– Transmission Losses : Absorption in water
– Transmission Losses : Attenuation in different Sediments
– Reflection of Sound
– Noise
• Pulse Length, Bandwidth and Resolution
– Attenuation in different Sediments
Sub‐Bottom Profiler Principles

16. Basic Sonar Equations
EL = SL – 2 TL + TS
Where EL = Echo Level, or received signal
SL = Source Level, in dB referenced to 1 μPa at 1m
TL = Transmission Loss, in dB
TS = Target Strength, a ratio in dB of the sound returned to the incident
intensity form a distant source
SL = 171 + 10 log PT +DIT
Where PT = Acoustic power in watts,
DIT = Directivity index of the transducer.
References
Principles of Underwater Sound, R.J.Urick
Fundamentals of Acoustics, Kinsler et al.
Sonar Acoustics Handbook, NURC (a NATO Research centre)
http://traktoria.org/files/sonar/references/NURC_sonar_acoustics_handbook_2008.pdf

17. Sonar Equations – Source Level
SL = 171 + 10 log PT +DIT
Where PT = Acoustic power in watts,
DIT = Directivity index of the transducer.
DIT = 10 log DF or DIT = 10 log (I beam / I omni )
Where DF = Directivity factor
For an idealised circular piston diameter d, DF
For a SB-216 transducer, diameter ≈ 160mm, centre frequency ≈ 9 kHz, we get DI ≈ 5 dB,
which means for a 3100 with a 200 W amplifier, SL ≈ 200 dB,
and for a 3200 with a 2000 W amplifier, SL ≈ 210 dB.

18. • Absorption losses are dependent
on frequency, but are not
significant at Sub‐Bottom profiler
frequencies.
• Spherical Spreading losses are
geometrical and independent of
frequency and are the dominant
in‐water transmission loss
mechanism for Sub‐bottom
Profilers.
• Attenuation in the sub‐bottom
sediments are frequency and
sediment type dependent, and
overall are the dominant
transmission loss mechanism for
Sub‐bottom Profilers.
Transmission Losses

19. • Spreading loss
– Spherical Spreading
Transmission loss is given by
20 log r
• When it hits the sea
bottom or surface,
spreading becomes
cylindrical
– Cylindrical Spreading
Transmission loss is given by
10 log r
Spherical Spreading Losses

20. • Attenuation in the sub‐
bottom sediments are
frequency and sediment
type dependent, and
overall are the
dominant transmission
loss mechanism for Sub‐
bottom Profilers.
• Plot of Normalised
Signal shows the way
different sediment types
affect different
frequency signals
Transmission Losses

21. • Deflection of the path of a
sound wave by an object or by
the boundary between two
media
• Acoustic properties of the
boundaries…
– Similar = less reflection
– Dissimilar = more reflection
• Acoustic Impedance Z = Vρ
– V is seismic wave velocity in the
material
– ρ is the density of the material
Reflection of Sound

22. Noise : Ambient Noise
• Ambient Noise sources
– Traveling through the sea, an
underwater sound signal becomes
delayed, distorted and weakened,
reflecting on boundaries of
underside surface of waves,
bottom and shores, bubbles,
suspended particles and marine
life.
– Tide, current, temperature
variances and wind also play on a
sound's final quality.
– Man made noise can also affect
the results
• Vessel Noise
– Sub‐Bottom profilers are largely in
the audio spectrum
– There is lot’s of vessel generated
noise here

23. • Type of bottom material
• Center frequency of the chirp pulse
• Presence of biological material
• Signal scattering
• Beam width
• Transmitted Power
Depth of Penetration

24. • Pingers / Pipeliners
• ORE, GeoAcoustics, SES etc.
• 3.5 kHz, 5 kHz, 7 kHz ….
• Boomers
• EG&G 240, Huntec, AAE
• 300 Hz – 6 kHz
• Sparkers
• AAE, GeoResources, SIG
• Frequency is tip and depth dependent
• Mini‐Airgun
• Sercel Sodera
• 300 Hz – 2.5 kHz
Traditional Systems

25. Penetration versus Resolution
The classic dilemma:
Low Frequency Sources
provide Penetration
• For an oscillating bubble,
frequency decreases with
increased energy.
– The larger the airgun, the lower the
frequency
• For transducers, the lower the
frequency, the larger they need
to be
– Very low frequency, high power
transducers are difficult to build.
High Frequency Sources
provide Resolution
• High Frequency transducers can
be smaller and lighter
– Making the towfish easier to deploy
• But there is limited
penetration
– Especially in coarse sediments

26. “The total energy output of
magnetostrictive sources is extended
by generating frequency modulated
pulses that sweep a range of
frequencies”
E.J.W. Jones
Marine Geophysics
Energy from transducers

27. • A Full Spectrum Sub‐
Bottom Profiler outputs an
FM pulse that is linearly
swept over a full spectrum
frequency range.
(e.g: 2 ‐ 16 kHz over 20 ms)
Full Spectrum Systems
The FM pulse is also called a CHIRP pulse, and although CHIRP stands for
Compressed High Intensity Radar Pulse, the name has stuck because of the
sound these sub‐bottom profilers make.

28. CHIRP Pulses
• CHIRP (or Broadband, or Spread Spectrum) Pulses
– Provide high energy signals, with superior resolution
– Implementation of matched filter processing
• After match filtering the returns are shorter in time
• As before, but with added white noise
http://en.wikipedia.org/wiki/Pulse_compression

29. • EdgeTech “Full Spectrum” pulse characteristics
– Bandwidth
• The wider the bandwidth, the better the resolution
– Length
• Longer pulses provide more acoustic energy
– Waveform
• Sweep has a linear variation of frequency with time.
• For “FM” shaped pulses the Full Spectrum wavelet is weighted
in the frequency domain to have a Gaussian like shape
(Blackman‐Harris window) which provides a great rejection of
the side lobes.
• Wideband (WB) pulses have a flat response over the entire
pulse bandwidth, so more low frequency content.
Pulse Options

30. • EdgeTech “Full Spectrum” pulse
characteristics
– Bandwidth
• The wider the bandwidth, the better the
resolution
– Length
• Longer pulses provide more acoustic energy
– Waveform
• For “FM” shaped pulses the Full Spectrum
wavelet is weighted in the frequency domain
to have a Gaussian like shape (Blackman‐
Harris window) which provides a great
rejection of the side lobes.
• Wideband (WB) pulses have a flat response
over the entire pulse bandwidth, so more low
frequency content.
• Sweep has a linear variation of frequency
with time.
Selection of Best Pulse
Pulse selection
The selection of the pulse is made on‐line
by the operator while profiling to achieve
the best imagery and taking into
consideration
• The minimum required penetration depth
• Seafloor sediment type

31. • EdgeTech “Full Spectrum” pulse characteristics
– Bandwidth
• The wider the bandwidth, the better the resolution
– Length
• Longer pulses provide more acoustic energy
– Waveform
• For “FM” shaped pulses the Full Spectrum wavelet is weighted in the frequency domain to have a Gaussian like
shape (Blackman‐Harris window) which provides a great rejection of the side lobes.
• Wideband (WB) pulses have a flat response over the entire pulse bandwidth, so more low frequency content.
• Sweep has a linear variation of frequency with time.
• Quadratic Pulses
– Waveform
• Sweep rate varies with time, with greater proportion of pulse length spent at lower part of the frequency range.
• Designed to help improve penetration.
• Dual Frequency Mode
– Alternates between two transmission pulses
– Two data streams
• Each utilising a different pulse.
Pulse Options

32. • Sub‐Bottom Profiler Operations
– Towfish Altitude
– Deployment methods
– Pipeline Detection
– Heave Compensation
Agenda : SBP Field Operations

33. • It's not necessary to tow the vehicle near the seafloor in order to get good results, it is
possible to get results with hundreds of meters of water column.
– In many cases our customers ‘shallow tow’ the sub‐bottom profiler towfish relatively near the surface, at a typical tow
depth of 5 to 10m. This approach is fine for regional geological analysis, where the area insonified on the seabed is
not that critical.
– In general, when towing the system near the surface, we advise that a 216 towfish based system can operate
effectively in water depths up to around 500m, and a 512 towfish based system in water depths up to around 1500m.
• Towing a sub‐bottom profiler system close to the seabed is generally only required where
very location specific ‘engineering’ data is required.
– Towing the close to the bottom reduces the area of the seafloor insonified, reducing the scattering, and also
producing a more focused beam which will improve spatial resolution. For the best results, the optimal height off the
seafloor would be about 5‐10 meters.
– The maximum amount of cable that the 3200 topside and SB‐512i towfish can run on is 500 meters which will limit
how close to the seafloor you can get, so in theory you could get the tow fish to a depth of around 150 meters with
500 meters of double armored cable.
– A 2000‐CSS or 2000‐DSS combined side scan and sub‐bottom profiler can run on coax armoured cable, and can be
deployed near the seabed in up to 300m of water for the 2000‐CSS and 2000m of water for the 2000‐DSS.
Towfish Altitude

34. Horizontal Resolution

35. Towfish Rigging / Deployment

36. Alternative Deployment
3100P - Pole
Mount option
Alternative
deployment for
the 424 and 216
Towfish
Custom Engineered Solutions
Raft or Bouy
solutions for
towing the
heavier 512
towfish behind
smaller vessels

37. Deployment
DON’T
Are your feet
wet?

38. • Conventional Configuration
– Two hydrophone arrays mounted in
the along track direction
– These give a narrow along track
beamwidth, and a wider across track
beamwidth
– This is good for general geological
survey operations
• Pipeline detection configuration
– A single transverse hydrophone
array
– Gives a wide along track beamwidth
– Which accentuates the parabola off
the pipeline
Pipeline Detection

39. • Methods
– Swell filter
– Sensor input
• Cleaner image
– Better representation
of bottom and sub‐
bottom
– Easier to interpret
Heave Compensation

40. • EdgeTech Sub‐Bottom Profiler Systems
– Towed Systems
• 3100
• 3200
– Hull Mount Systems
• 3300
– AUV / ROV Systems
Agenda : EdgeTech SBP Systems

41. Towed Systems
3100-P
Portable system
for smaller boats
with a choice of
two different
towfish:
216 2 – 16 kHz
424 4 – 24 kHz
3200-XS
Rack mount
system with a
choice of three
different towfish:
512 500 Hz – 12 KHz
216 2 – 16 kHz
424 4 – 24 kHz

42. Towfish
SB‐0512i SB‐216S SB‐424
Frequency Range 500 Hz – 12 kHz 2 – 16 kHz 4 – 24 kHz
Pulse Type Frequency Modulated
Vertical Resolution
(depends on Pulse selected)
8 – 20 cm 6 – 10 cm 4 – 8 cm
Penetration (typical)
In coarse calcareous sand
In clay
20 m
200 m
6 m
80 m
2 m
40 m
Beam Width
(depends on centre frequency)
16° ‐ 32° 17° ‐ 24° 16° ‐ 23°
Size (cms) 160 x 124 x 47 105 x 67 x 40 77 x 50 x 34
Weight 190 kg 76 kg 45 kg
Cable requirements 3 shielded twisted pairs (5 conductors used)
Maximum Operating Depth 300 m
Tow Speed 3 – 4 knots optimal, 7 knots max. safe operation

43. SB‐512 Data Examples
Sand hill over top of marine high‐stand/on‐lapping sands, which are over
top of limestone, which represents seismic bottom for this image.
This is 8 – 10 meters of penetration in relatively coarse sand, until
you hit the limestone.

44. SB‐512 Data Examples

45. 3300 Hull mount Systems
DW‐216 DW‐106
Frequency Range 2 – 16 kHz 1 – 8 kHz
Pulse Type
Full Spectrum chirp frequency modulated pulse
with amplitude and phase weighting
Vertical Resolution
(depends on Pulse selected)
6 – 10 cm 15 – 25 cm
Penetration (typical)
In coarse calcareous sand
In clay
6 m
80 m
15 m
150 m
Hull Mount Array Configuration
options
4 element (2 x 2)
9 element (3 x 3)
16 element (4 x 4)
25 element (5 x 5)
3 element
5 element
7 element

46. 3300 System Enhancements
Transducer
Selection
Receive Mode
(Automatic)*
Mode A Mode B *
Transmit and Receive on
the same transducers
Transmit and Receive on
different transducers
Transmit Bus Tx & Rx Tx
Off Off Off
Receive Bus Off Rx *
*Switching any transducer into receive only mode,
automatically enables Mode B
Switchable array configuration
• Allows the operator to change the
array beampattern, e.g. for pipeline
crossing.
• The system can be set to transmit and
receive on different transducers, which
allows longer pulses to be used in
shallow water operations

47. 3300 : Data Example
EdgeTech 3300HM
4x4 Array of KT-216 transducers
Chirp operating at 1.5 - 9.0 kHz
Water depth = 200 - 300 m (approximately)
Time lines represent 16 m vertical depth (based on 1600m/s below seabed)
Navigation fixes are 50m per division

48. • Range of Transducer Options
AUV / ROV Mounted Systems
DW‐424 DW‐216 DW‐106
Frequency Range 4 – 24 kHz 2 – 16 kHz 1 – 10 kHz
Pulse Type
Full Spectrum chirp frequency modulated pulse
with amplitude and phase weighting
Vertical Resolution
(depends on Pulse selected)
4 – 8 cm 6 – 10 cm 15 – 25 cm
Penetration (typical)
In coarse calcareous sand
In clay
2 m
40 m
6 m
80 m
15 m
150 m
Beam Width
(depends on centre frequency)
15° ‐ 25° 15° ‐ 25° 28° ‐ 36°

49. • Transmit and Receive on the Transducer
– Reduced Hardware
• Adds a T/R (Transmit/Receive) switch, but removes the need for separate receive hydrophones.
– Limits Pulse Length
• Limits the pulse length that can be used when close to the seabed – need to stop transmit pulse, and eliminate
ringing, before 1st receive.
• Not recommended for AUV’s.
• Separate PZT receive Hydrophone arrays
– Pulse length independent of altitude
• Can receive on hydrophones whilst still transmitting.
– Linear arrays in parallel used to define receive beam pattern
• Separate PVDF receive Hydrophone panels
– Pulse length independent of altitude
• Can receive on hydrophones whilst still transmitting.
– Standard panel sizes or Custom built
• Custom sizes can be designed to fit vehicle
• Multiple receive options for different applications.
AUV / ROV Receive Options

50. Sub‐bottom Profiler on AUV’s
AUV Sub-Bottom data
DW-106 Transmit
Quadratic pulse
PVDF receive arrays

51. • EdgeTech Full Spectrum Sub‐Bottom Profilers offer:
• Selectable FM Pulses
• Matched Filter Correlation
• Up to 4 cm Vertical Resolution
• 20‐30 dB Improved SNR Over Conventional systems
• Wide Band Projectors
• No Spatial Side Lobes
• Reduced Sea Surface Effects
• EdgeTech offers sub‐bottom profiling systems for a
variety of platforms:
• Towed
• Hull Mount
• Hosted Platform (AUV, ROV etc)
• Custom, etc…
• EdgeTech systems offer various file format options
• EdgeTech native .JSF
• SEG‐Y
• .XTF
Summary of EdgeTech SBP’s

52. • Maintenance and Troubleshooting
– Standard Maintenance
– System IP Configuration
– Sonar.exe diagnostics
– Software Maintenance
– System Hardware
• 3100
• 3200
Agenda : Troubleshooting

53. Standard Maintenance
• Sub‐Bottom Profilers are low maintenance
• DO – wash them with fresh water before storing
• Look after Connectors
• DO ‐ keep connectors clean
• DO ‐ use a small amount of connector grease
• DO ‐ fit a blanking plug to unused connectors
• DON’T – deploy a towfish without blanking plugs ‐ They are not depth rated when
left open faced !
• Keep Transducers Clean
• DON’T ‐ get connector grease on the transducer
• DO – clean them with water with some washing up liquid in it ‐ breaks surface
tension

54. 3100 System IP Configuration
3100 IP Addresses
Laptop / PC
Wired LAN 192.9.0.99
Wireless LAN 192.9.0.100
Topside Processor
Wireless Bridge 192.9.0.225
CPU 192.9.0.31

55. 3100 Diagnostics ‐ Connecting
• Use Desktop Link
• If you have to create a
remote desktop link
– 192.9.0.31
– Username : Administrator
– Password : admin

56. Diagnostics – Sonar.exe
• ‘Sonar’ should appear in
the display.
• Shows Self Test result
• It shows any errors and
Alerts
– In this case Alert 22 NET
TIME, as there was no GPS
connected to the topside to
sync the system to.

57. Diagnostics – Sonar.exe
• Go to File > Show Status
• Select ‘POST’ button
• It provides voltage
levels etc.
– CPU voltages
– 48v Amp power
• OK button to close

58. Discover SB ‐ Configuration files
• You can Save and Load
Configuration files
– It’s a good policy to save
configurations you know work !
• Discover will automatically
save it’s configuration when
you shut it down

59. 3100P Topside Block Diagram

60. 3200 Hardware : Rear panel

61. 3200 : Legacy AB amplifier
• The output from the amplifier
can be checked with an
oscilloscope.
• The CHIRP signal should be
around 170V peak to peak.

62. 3200 : New Class D amplifier
• Class D “push pull” amplifier
• Operated in a bridged mode
• Output levels are preset via an
ethernet interface
• The front panel controls are disabled

63. • Data Interpretation
– File Formats
– Sub‐bottom data interpretation
– Discover Sub‐bottom software
• Display options
• Gain Settings
• Recording Options
Agenda : Data Interpretation

64. File Formats – .jsf files
• By default the sub‐bottom data in a .jsf file is stored as complex samples, X + jY, two
numbers per sample.
• This is the Analytic signal data format (http://en.wikipedia.org/wiki/Analytic_signal )
• These complex data samples are of the format x and y, where
y= A sin(phi)
x= A cos(phi)
and are represented as a number x + j*y. Where j =sqrt(‐1)
• So from this you will see that sqrt (x^2+y^2) = A the amplitude (the magnitude of the complex
number), and the phase is phi = arctan (y/x).
In computing use phi = atan4(y,x) as this will return a value between 0 and 2π.
• However, please note that the data displayed on the Discover Sub‐bottom software screen
just shows the amplitude A, and the phase is discarded. This is typical for sub‐bottom
profiler data where the display is the envelope of the amplitude. Similarly, the SEG‐Y files
created by Discover just record the amplitude (to comply with the format standard), and
again the phase is discarded.

65. File Formats – SEG‐Y files
• EdgeTech strictly adheres to the Rev.1 (2002) formalization of the standard, which can be
found at: http://www.seg.org/resources/publications/misc/technical‐standards
• The SEG‐Y standard allows a great deal of flexibility about the way that both the headers,
and the data words, can be written
• The first issue is that systems will often only read a sub‐set of the full range of formats allowed
under the SEG‐Y standard. The most common of these, are ones that will only read ASCII
characters and IEEE floating point numbers, or EBCDIC characters and IBM floating point
numbers.
• The key here is to choose the SEG‐Y file creation options that match what the reader will accept.
Knowing what your SEG‐Y reader will accept is important.
• Some readers will read a subset of standard SEG‐Y with restrictions based on the first
systems they supported, and lack of support for trace size changes fits into this category.
According to the standard, the size field in the trace header supersedes the value in the
binary header, but some systems still use the File header value for the whole file.
• To alleviate this problem we have added the option in DISCOVER to start a new file on size
changes. This works well as long as the system is not using multi‐ping logic, which constantly
adjusts the window sizes. In those cases, the result is too many SEG‐Y files.

66. • Transmit (T0)
• Bottom Echo
• Layers
• Multiples
SBP Data Interpretation

67. Interpretation ‐ Multiples
Bottom = Water Depth (WD)
– Fish Depth (FD)
1st Multiple = 2x Water Depth
(2WD) – Fish Depth (FD)
2nd Multiple = 3x Water Depth
(3WD) – Fish Depth (FD)

68. Interpretation ‐ Multiples
Bottom = Water Depth (WD) – Fish Depth (FD)
1st Multiple = 2x Water Depth (2WD) – Fish Depth (FD)
2nd Multiple = 3x Water Depth (3WD) – Fish Depth (FD)

69. • Vertical Resolution
• Attenuation in the
Sediments
• Acoustic Impedances of
layers
Interpretation ‐ Layers

70. Geological Survey
Analysis of the Four Brothers
Slump,
Lake Champlain
Ghosh, Supriti J., 2012.
Unpublished Senior Thesis,
Middlebury College, Middlebury,
VT

71. Shallow Gas detection
Shallow Gas
“masks”
Acoustic data

72. Point source reflections

73. Pipeline and cable detection

74. • Pull Down Menus
for Command and
Control
• Toolbars for
frequently used
commands.
• Main Sonar Data
Display
• Control Panel ‐
tabbing dialog
boxes for
modifying
parameters.
• Status bar for
sonar control and
sonar data status.
Discover SB Screen Layout

75. • Pull Down Menus
for Command and
Control
• Toolbars for
frequently used
commands.
• Main Sonar Data
Display
• Control Panel ‐
tabbing dialog
boxes for
modifying
parameters.
• Status bar for
sonar control and
sonar data status.
Discover Sub‐Bottom Screen Layout

76. • Click and drag left button in
scale bar to zoom in on a region.
• Double Click left mouse button
in scale bar to zoom out on the
display so that all data is
displayed.
• Click and release the left mouse
button in the ‘scope window to
set the current bottom track
position and threshold
• Click and drag the left button to
set the bottom track window. If
only a very small drag is
performed then the track range
is set to zero and the tracker is
disabled.
• Move the mouse pointer to a
ping and status information will
be displayed in the main status
bar.
• Left click in data to save target
info into CSV file
• Right click on a layer to digitize
Discover Sub‐Bottom Screen Clicks

77. • Sonar Control
• Display
• Status Bar
• Network
• Navigation
• Printer
• Alerts
• Logs
• Miscellaneous
• Record
• Playback
• Image Capture
Discover SB Control Panel

78. Discover SB Sonar Control

79. Discover SB Recording
• File Formats
– JSF
– XTF
– SEG‐Y
• SEG‐Y Options
– Data format
– Header format
– New file on size change
• XTF Options

80. Discover SB Interfaces
• Default settings for a
3100
• Lat / Long
– GGL or GGA
– VTG
– ZDA
• X / Y Coordinates
– GXY
– GGU
• Event Marks
– EVT

81. Discover SB Display
• Gain Control
– Alternative to Toolbar
• Bottom Tracker
– Alternative to Screen
clicks
• Heave compensation
– Swell filter or Heave
Sensor

82. Discover SB ASCII and jpg Files
• NAV track file
• Bottom / Layer
Digitisation file
• Jpeg image capture

83. Thank You!