acoustic detection and bottom classification · sssand!!!unmanned!underwater!vehicle(uuv)! sss...
TRANSCRIPT
Acoustic detection and bottom classification
Zygmunt Klusek
• detection, recognition and mapping of dumped munitions fusing the acoustic, magnetic and visual imaging methods
• technology development in improving the acoustical imaging of buried ammunition
• arrangement of the data base of all collected information for integrated system that includes geographical coordinates and the precise characteristics of the targets.
GOALS OF THE PROJECT (SELECTED ISSUES)
• INTRODUCTION
• ACOUSTIC METHODS/MEASUREMENT SETUP SIDE SCAN SONAR MULTIBEAM SONAR
NEW TECHNOLOGIES
• COMPLEMENTARY METHODS – MAGNETOMETER, ROV • BOTTOM RECOGNITION
Survey Equipment
SSS Klein 5000, Gradiometer 4-axis Marine Magnetics Multibeam Reson 7125 SV2 200/400 kHz
ROV Ocean Modules V8 MVP 200 Broke Ocean MVP Fish USBL
SSS Winch
Technology of the amuni=on detec=on
Three stages of geophysical surveys in the amuni=on detec=on and recogni=on required employment of: • Acoustic techniques : Side Scan Sonar, Multibeam Sonar, chirp broadband echosounder/ multifrequency split-‐beam echosounders/ parametric sonar • Magnetometric techniques • ROV – positioning, visualisation and sampling
To change to to "View" and click "Header and footer"
To change to to "View" and click "Header and footer"
Hydroacoustic will also deliver data to prepare bathymetric and type of sediment maps (FOR MODELLING OF TRANSPORT OF TOXIC SUBSTANCES).
SIDE SCAN SONAR
¡ The sensor is towed behind the ship near sea bottom. The swath width is typically up to 100 m.
The image part with relationship ID rId4 was not found in the file.
SSS and unmanned underwater vehicle (UUV)
SSS SIGNAL PROCESSING
Target detec=on – hard boNom
The image part with relationship ID rId3 was not found in the file.
Targets
The image part with relationship ID rId7 was not found in the file.
The image part with relationship ID rId8 was not found in the file.
The image part with relationship ID rId9 was not found in the file.
SSS IMAGES PROCESSING
RAW DATA PREPROCESSING PROCESSING: GEOMETRY &
POSITION CORRECTIONS MAPPING
POSTPROCESSING:
INTERPRETATION BY OPERATOR OR
COMPUTER ASSISTED
c PRODUCT
c ADDITIONAL INFORMATION
DECISIONS
• HIGHER SHIP SPEED (BIGGER AREA COVERING) – LOWER RESOLUTION (ALONG PATH)
• HIGH VS. LOWER FREQUENCY • HOW MANY PIXELS, RESAMPLING ? REDUCING GREYS LEVELS? (GAINS -‐ MEMORY, TIME CONSUMING OPERATIONS)
• WHAT KIND OF TRANSFORMING OPERATIONS (SMOOTHING, STRETCHING, CONTRASTS, COLOURS, ETC.)
STRATEGIES OF SAMPLING (WITH SONARS)
To change to to "View" and click "Header and footer"
PLANNING AREA COVERAGE
• If full coverage of the seabed is required swaths be should overlapped
by at least 50% to achieve 100% coverage. • Swaths are typically overlapped by 20 to 30%. • To achieve the maximum coverage possible, the transducers must be a
suitable height above the seabed (between 10 to 20% of the swath width).
• For most 100kHz systems 10% per side with swaths widths could be maximized up to 200m per side with the fish traveling 20m from the seabed.
Op=mis=cally • 4 *1850[m/hour]*200 m*1 hour/0.3 1 sq.km/hour
Product – map of target distribution All classes of targets Subarea T
EQUIPMENT MulTbeam Sonars
Appropriate for imaging of the wrecks, protruded objects and seafloor mapping in water depths between 0.5 and 150 meters.
Theoretically swath width 10 x water depth, however for the above 100 m depths and sound refraction the real swath width, target recognition is substantially diminished.
However - the minimal diameter of the spot at 100 m depth is 2.5. m !
MAIN TASKS –bottom topography + detection and visualisation of bigger objects
Technology of the amuni=on detec=on
• Even though, in the last couple decades, many systems and algorithms had been introduced.
• One of the limitaTons of real-‐Tme recogniTon systems is the computaTonal or hardwer complexity of exisTng approaches.
• The general problem of these systems is their computaTonal cost in data pre-‐preparaTon and transformaTon to other spaces such as eigenspace, Fisherspace , wavelet transform or cosine transform
To change to to "View" and click "Header and footer"
Newest technologies
• Synthe=c aperture sonar (SAS) is a form of sonar in which sophis=cated post-‐processing of sonar data are used in ways closely analogous to synthe=c aperture radar.
• Synthe=c aperture sonars combine a number of acous=c pings to form an image with much higher resolu=on than conven=onal sonars, typically 10 =mes higher. (4-‐5 cm)
Magnetometric and Remote Operated Vehicle (ROV)
Probably Chemical Munition Objects The image part with relationship ID rId5 was not found in the file.
The image part with relationship ID rId6 was not found in the file.
Acous=c boNom recogni=on one beam classical echosounder
Klusek, Tęgowski, 1999 Tęgowski, , 2002
Acous=c boNom recogni=on
• SIDE SCAN SONAR • BoNom type recogni=on • (Object-‐oriented classifica=on of • sidescan sonar data for mapping • benthic marine habitats)
• (Univ. of Gdansk • IO PAS, Sopot • P.Paukszys)
•
Acous=c boNom classifica=on
Mul=beam sonar
The image part with relationship ID rId2 was not found in the file.
Tegowski, etl al. 2011
Thank you for aNen=on
Kiitos