sounding,high resolution shallow seismic reflection and underwater sonographic

8/9/2019 SOUNDING,HIGH RESOLUTION SHALLOW SEISMIC REFLECTION AND UNDERWATER SONOGRAPHIC

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ECHO SOUNDING,HIGH RESOLUTION SHALLOW SEISMICREFLECTION AND UNDERWATER SONOGRAPHIC

METHODS FOR CONSTRUCTION OF OFFSHORESTRUCTURES

Seminar by

ANUP P NAIKNIKA BHINGARDE

RAGHAVENDRA PRABHUSABNA THILAKAN

Gi!e! byDr A K CHAUBE"

C#ie$ %&ien'i%'Ge()(*i&a) O&ean(*ra+#y Dii%i(n

CSIR-NIO, D(na Pa)a, G(a


2/79

Ob.e&'ie ($ %'!y

T#e main (b.e&'ie ($ '#e +r(.e&' /(r0 are1

Un!er%'an!in* $n!amen'a)% ($ e( %(n!in*, %i!e %&an %(nar, #i*#re%()'i(n %ei%mi& re$)e&'i(n 'eni2e% em+)(ye! '( %'!y %eabe!an! %b-%eabe! $ea're% ($ near ($$%#(re re*i(n

Un!er%'an!in* $n!amen'a)% ($ Gr(n! Pene'ra'in* Ra!ar 3GPR4'eni2e em+)(ye! '( %'!y %b %r$a&e (n%#(re &(a%'a) $ea're%a!.a&en' '( near %#(re re*i(n

Learnin* !e'ai)% ($ a&2i%i'i(n ($ ba'#yme'ry, %(n(*ra+#y ($ '#e %eabe! an! %ei%mi& re$)e&'i(n !a'a (nb(ar! %rey b(a'5

Learnin* +r(&e!re $(r +r(&e%%in* '#e a&2ire! ra/ !a'a %in*%'an!ar! %($'/are an! in'er+re'a'i(n ($ +r(&e%%e! !a'a5

Syn'#e%i%in* !e'ai)% ($ '#e !a'a a&2i%i'i(n , +r(&e%%in* an!in'er+re'a'i(n5


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ECHO SOUNDING METHOD


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INTRODUCTION

E( %(n!in* i% a *e(+#y%i&a) 'eni2e ($ $in!in* !e+'# ($ /a'er by'ran%mi''in* %(n! +)%e% in'( /a'er5 T#e 'ime in'era) be'/eenemi%%i(n an! re'rn ($ a +)%e i% re&(r!e!, /#i i% %e! '( !e'ermine'#e !e+'# ($ /a'er &(n%i!erin* %+ee! ($ %(n! in /a'er5

Lea! )ine an! %(n!in* +()e /ere '#e ear)ie%' me'#(!% %e! $(r !ire&')ymea%rin* /a'er !e+'#5

T#e E(-%(n!in* 'eni2e /a% !ee)(+e! by Pr($e%%(r Fa%%en!enin 6768 an! #a% been %e! in #y!r(*ra+#i& %reyin* %in&e '#en5

Sin*)e Beam E( S(n!er% 3SBES4 %'i)) remain '#e 'ra!i'i(na)e2i+men' %e! (n #y!r(*ra+#i& %rey% /(r)!/i!e, #(/eer M)'iBeam E( S(n!er% 3MBES4 an! Airb(rne La%er S(n!in* 3ALS4%y%'em% n(/ +r(i!e a)m(%' '('a) %ea$)((r &(era*e an! !e+'#mea%remen'5


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SOUND PROPAGATION IN SEA WATER

T#e %+ee! ($ %(n! C, i% a $n&'i(n ($ 'em+era're 3T4, +re%%re 3P4 an!%a)ini'y 3S45 F())(/in* e2a'i(n %#(/% '#e !e+en!en&e ($ %(n! %+ee!(n '#e%e $a&'(r%1

C3T,P,S4968875: ; 85< T ;=5=>> T:

; 65?73S@?>4;=5=6< D

W#ere, C is in m/sec, T in Celsius, D (Depth) in metres and S in partsper thousand.

S(n! +r(+a*a'i(n i% in '#e $(rm ($ a''ena'i(n, re$)e&'i(n an!re$ra&'i(n5


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ACOUSTIC PARAMETERS

T#e ara&'eri%'i&% ($ an e( %(n!er are !e'ermine! by '#e a&(%'i&+arame'er% name)y1

65 Fre2en&y

:5 Ban! /i!'#

?5 P)%e )en*'#

. T#e 'ran%!&er% are (ne ($ '#e e( %(n!er% &(m+(nen'% i' i%'ran%!&er ara&'eri%'i&% /#i !i&'a'e %(me ($ '#e (+era'in*$ea're% ($ an e( %(n!er5 T#e 'ran%!&er% are '#e !ei&e% %e! $(r

'ran%mi%%i(n an! re&e+'i(n ($ '#e a&(%'i& +)%e%5

. Tran%!&er% are &)a%%i$ie! /i'# re*ar! '( '#eir (+era'in* +rin&i+)e,i5e5 ma*ne'(%'ri&'ie, +ie(e)e&'ri&, an! e)e&'r(%'ri&'ie5


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SINGLE BEAM ECHO SOUNDER

T#e%e e( %(n!er% are !ei&e% $(r !e+'# !e'ermina'i(n by mea%rin*'#e 'ime in'era) be'/een '#e emi%%i(n ($ a %(ni& (r )'ra%(ni& +)%ean! '#e re'rn ($ i'% e( $r(m '#e %eabe! 5

An e( %(n!er /(r0% by &(ner'in* e)e&'ri&a) ener*y, $r(m '#e +)%e*enera'(r, in'( a&(%'i& ener*y5 A% '#e 'ran%!&er% !( n(' 'ran%mi' ina)) !ire&'i(n%, '#e a&(%'i& ener*y i% +r(.e&'e! in'( '#e /a'er in '#e $(rm($ a er'i&a))y (rien'e! beam5

T#e a&(%'i& +)%e 'rae)% '#r(*# '#e /a'er &()mn an! #i'% '#e%eabe!5 T#e in'era&'i(n /i'# '#e %ea$)((r re%)'% in re$)e&'i(n,'ran%mi%%i(n an! %&a''erin*5

T#e re$)e&'e! ener*y /#i re'rn% '( '#e 'ran%!&er, '#e e(, i%%en%e! by '#e 'ran%!&er5


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MULTI BEAM ECHO SOUNDERS

M)'i Beam E( S(n!er% 3MBES4 are a a)ab)e '(() $(r !e+'# !e'ermina'i(n/#en $)) %ea$)((r &(era*e i% re2ire!5 T#e%e %y%'em% may a))(/ &(m+)e'e%ea$)((r en%(ni$i&a'i(n /i'# '#e &(n%e2en' in&rea%e in re%()'i(n an!!e'e&'i(n &a+abi)i'y5

Prin&i+)e ($ (+era'i(n ($ m)'i beam e( %(n!er i%, in *enera), ba%e! (n a $an

%#a+e! 'ran%mi%%i(n +)%e !ire&'e! '(/ar!% '#e %ea$)((r an!, a$'er '#ere$)e&'i(n ($ '#e a&(%'i& ener*y by '#e %eabe! %eera) beam% are e)e&'r(ni&a))y$(rme!, %in* %i*na) +r(&e%%in* 'eni2e%, /i'# 0n(/n beam an*)e%5

T#e in'er%e&'i(n% ($ '#(%e beam% in '#e %ea$)((r +)an are '#e $(('+rin'%3en%(ni$ie! area%4 $(r /#i '#e !e+'#% are mea%re!5

M)'i beam %y%'em% /i'# '#eir &a+abi)i'y ($ $)) %ea$)((r en%(ni$i&a'i(n

&(n'rib'e '( a be''er %ea$)((r re+re%en'a'i(n an!, /#en &(m+are! '( SBES, '(#i*#er ma++in* re%()'i(n5

H(/eer, a% $ar a% '#e !e+'# mea%remen'% are &(n&erne!, re%()'i(n /i))!e+en! (n '#e a&(%'i& $re2en&y, 'ran%mi' an! re&eie beam /i!'#% an! (n '#ea)*(ri'#m %e! '( +er$(rm %eabe! !e'e&'i(n 5


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MULTI BEAM ECHO SOUNDER


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PROCESSING ANDPRESENTATION OF DATA

A&2ire! e( %(n!in* !a'a are re2ire! '( be &(rre&'e! $(r %#i+%m('i(n, nai*a'i(n, %(n! e)(&i'y, an! 'i!a) aria'i(n%5

In +ra&'i&e a' m(%' $(r +r(&e%%in* %'e+%, /#i are %mmarie! be)(/,are nee!e! $(r '#e ma.(ri'y ($ a&2ire! e( %(n!in* !a'a1

A++)i&a'i(n ($ a++r(+ria'e %(n! e)(&i'y +r($i)e

A++)i&a'i(n ($ &(rre&'e! 'i!e%

E!i'in* ($ %+ri(% !e+'# !a'a

Genera'i(n ($ *ri!!e! !a'aba%e

T#e e( %(n!in* !a'a n(rma))y are +re%en'e! in '#e $(rm ($1

65 ba'#yme'ri& +r($i)e%:5 ba'#yme'ri& &(n'(r ma+ 3b('# :D ?D4 an!,

?5 *ri!!e! ba'#yme'ry ma+5


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Pre%en'a'i(n ($ *ri!!e! ba'#yme'ry ($ a %rey area %#(/in* /a'er !e+'# 3m4 a' *ri!&(rner5 Sb%&ri+' ($ ann('a'e! nmber in!i&a'e% !e+'# in !e&ima) me'er3F(r eam+)e, 8 im+)ie% 85 m45


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Pre%en'a'i(n ($ *ri!!e! ba'#yme'ry 3m4, /a'er !e+'# &(n'(r 3m4 an!&()(r &(!e! ba'#yme'ry ($ a %rey5


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SIDE SCAN SONAR

METHOD


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Introduction to Side Scan Sonar It is a high resolution seismic

tool that provides coverage toboth sides of a surveyvessels track.

Side scan sonar wasdeveloped during World War IIat the British NationalInstitute of Oceanography todetect submerged enemy

submarines. It is an acoustical instrument

that is normally towed behinda vessel and emits acousticalsignals to both sides.

Side scan sonar

tow!sh


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Working of Side Scan SonarIn side"scan sonar systemsacoustical energy is pro#ectedlaterally from a pair oftransducers mounted in a

towed cylindrical body or$tow!sh.%

&lectrical energy suppliedthrough the electromechanicaltow cable is applied to thepie'oelectric transducers in the

tow!sh.Side"scan sonar transducerstypically vibrate at preselectedfre(uencies from )* k+' to ,-+'.

Side Scan Sonar inoperation


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ypical Side Scan Sonar /omponents


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Side Scan Sonar 0eometry


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/ont..he distance of a target

perpendicular to the lineof travel can be

calculated once theheight of the tow!shabove the bottom isknown 1as shown in the!gure2 by simple

trigonometry.

/alculation of slantrange


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/ont..he height of a target can

be calculated using similartriangles

which can be written as3

/alculation of targetheight

ss

f

s

t

LR

H

L

H

+

=

ss

sft

LRLHH

+

=


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4rinciples of Side Scan Sonarhere are two di5erent operational

modes for sonar3

,2 4assive sonar3

Where an acoustic noise source isradiated by the target and the

sonar only receives the acoustic

signals

62 7ctive sonar3

Where the sonar itself transmits an

acoustic signal which again

propagates to a re8ector 1or target2

which again re8ects the signal back

to the sonar receiver

ransmitter

9eceiver

9ange

Ob#ect

ransmitter

9eceiver

9ange

Ob#ect

9eceiver

ransmitter


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4rocessing of SSS :atahe side scan sonar record is also known as a ;sonogram. he

sonogram is of varying shades with each shade a function ofthe intensity of the returning acoustical pulse. he strongerthe returning pulse the darker the image.

Sonogram often shows striking variations in brightnesscaused by changing altitude of the tow!sh making the imagesdi


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/ont..

0eometric /orrection"Bottom racking slantrange correction layback1cable out2 o5sets 1:04S2

Signal processing" 7pplyinggain to SSS data in order topresent the best possibleimage 1imageenhancement2.

Sonogram 1a2 pre" and 1b2 post"bottom tracking.

1a2 1b2


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Interpretation of Side Scan SonarImages

wo dark parallel linesrepresenting the initial acousticalpulse run #ust right and left of thecenter of the sonogram.

he surface return 1line B2 is oftenthe ne=t line closest to the center

line 1line 72.>ine / the initial bottom return isrecogni'able as the start of thedarker tone. otal water depth canbe calculated by adding thedistances on the sonogram of the

output pulse to the surface 17 to B2and the output pulse to the bottom17 to /2.

he dark line perpendicular to theline of travel 1line &2 is an eventmark created for later reference.

Interpretation of a side scan sonarrecord.


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?actors 75ecting Interpretation of Sonar

Images7 number of factors a5ect the intensity of the returning signal

which includes3 7coustic re8ectivity of the target Slope of thetarget face /ontrast between the target and surroundingmaterial and the number of re8ecting surfaces.

Target material and orientation infuences

7coustic 9e8ectivity is a function of the acoustic impedanceofthe material.

7coustic impedance @ A = c

where A @ material density c @ speed of sound through the material

he coarser the sediment the higher the re8ectivity.

herefore gravel re8ects more acoustic energy than sand whichre8ects more than silt or clay.


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/ont..Vessel speed eects

:istortion parallel to the trackline of the tow!sh occurs due

to varying boat speeds.

:istortions perpendicular to the line of travel is a function ofthe height of the !sh and the distance of the ob#ect from the!sh and oscillations in these positions.


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>imitations of Side Scan SonarWave e5ects3

4eriods for successful survey is limited to seasons oflow wave energy i.e summer months.

/urrent conditions3-a#or problem occurs when the current isperpendicular to the path of survey vessel.

Other site limitations3

-aintaining constant speed and tow!sh elevationre(uired for good results.

4resence of other vessels can make it di


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&ngineering 7pplication

Side"scan sonar is a potentially useful tool for the reconnaissance andinspection for coastal structures.

Side"scan sonar has been used for a variety of coastal engineering relatedapplications. It is used to !nd out ob#ects lying on the sea8oor before

starting construction of any o5shore structures such as o5shore platform#etty single point mooring intake and outfall pipe line laying etc.

It is proved to be an e5ective monitoring tool for monitoring disposal sitesof dredged material at near shore and o5shore sites. 7s the nearshore ando5shore open"water disposal of dredged material becomes increasinglypopular the need to monitor these disposal sites will become moreimportant.

4re and post"dredging sediment distribution mapping.

4ipeline and cable route surveys.

Site surveys for drilling rigs bridges etc.

-apping seamounts ocean ridges and other ma#or tectonic features.


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Sonogram showing underwater wreck debris of MVRi!er "rincess which grounded o5 /andolim coast0oa during une 6*** 1after /haubey et al. 6*,62. It was

detected during side scan sonar survey operation.


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HI#H RESO$%TION SHA$$O&SEISMICRE'$ECTION METHOD


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#ENERA$ (AC)#RO%ND

-arine seismic re8ection method is the most importantgeophysical methods employed in the o5shore environment toobtain a comprehensive picture of the sea"8oor morphology andunderlying shallow stratigraphy.

*"ICA$ A""$ICATIONS

,. -ineral e=ploration

6. ?oundationstudies

C.+arbour development

D. /ableEpipeline surveys

). It is also widely used to identify and characteri'e near"surface tectonic deformation in areas concerned with

earth(uake ha'ards.


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EN#INEERIN#A""$ICATION

+igh resolution seismic re8ection surveying is themost widely used geophysical techni(ue sincearound ,FG*

THIS METHOD IS E+TENSIVE$* %SED TO CARR*

O%T ,

,. ?oundation studies for o5shore platforms6. +arbour developmentC. /ableEpipeline rooting

D. Seabed surveys for bridges). -apping of lateral continuity of lithologic unitsH. o obtain Water table. o locate ?racture.


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HI#H RESO$%TION SHA$$O& SEISMIC

RE'$ECTION TECHNI-%E

Seismic re8ection method involves the measurement of the two"way travel time of seismic waves transmitted from sea"surface

and re8ected back to the surface from the interfaces betweencontrasting sub"surface layers.

he re8ected signal is detected on sea surface using an arrayof hydrophones.

J

J


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THE 'O%R (ASIC COM"ONENTS IN AN* SEISMIC

RE'$ECTION S*STEM ARE

,. 7 sound source that emits acoustic impulses orpressure waves.

6. 7n energy source to store energy for the soundsource.

C.7 hydrophone receiver that converts the re8ected

acoustic signalsto electrical signals.

D. 7 display unit that makes a permanent record of there8ected signals.


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(ASIC "RINCI"$E

he seismic method mainly uses sound waves which arelongitudinal or compressive waves 1also called 4"waves2 in whichmotion direction of particles in the medium is parallel to thepropagation direction of the wave.

In marine seismic work we are concerned primarily with pressurewaves 14"wave2 and the propagation velocity of such a wave is givenby3

Where Vp is velocity of P wave in the mediumk is the bulk modulus. is the shear modulus. is the density of the medium.


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SCHEMATIC DIA#RAM O' SEISMIC RE'$ECTION DATAAC-%ISITION AT SEA


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S%(. (OTTOM"RO'I$ER

he selection of an acoustic source is often based upon there(uirements for resolution and depth of penetration.

+owever e(ually important considerations are the cost

si'e ease of operation maintenance and availability of theenergy source and acoustic source.

he acoustic source re(uires some form of primary energy1electrical2 which is developed by the system onboard thesurvey platform 1small boat or ship2 and each employs a

device in the water that converts stored energy to anacoustic pulse.


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(OOMER

he boomer is often classed as displacement type devicebecause the rapid movement of a 8at rounded aluminium plateagainst the water produces the acoustic signal.

he motion of the plate is produced when electrical energy stored

in the power supply is rapidly discharged through the coil locatedin the transducerK a magnetic !eld is developed in the coil.

his magnetic !eld opposes the induced magnetic !eldgenerated in the aluminium plate resulting in a rapid repulsion

action of the plate .

he !elds decay very rapidly and return spring forces the plateback to the initial position. he acoustic signature generated is ofshort duration and relatively high amplitude having acharacteristic bandwidth of D**"D*** +'.


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S"AR)ER

he sparker is a low fre(uency relatively high"powered

energy sound source utili'ed for deep penetration sub"bottom pro!ling in salt water.

Sparker systems are available which operates in the ,**"6** kilo#oules range but these are used as sources with

multi"channel seismic systems not in continuous sub"bottom pro!ling.

Sparker sources used in pro!ling are usually limited to therange of 6**",**** #oules and generally there is littleadvantage to be gained in a further increase in energybeyond C*** #oules.

Hig/ resolution s/allo0 seismic multi.tips


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+L:9O4+ON&7 hydrophone is a microphone designed to be used underwater

for recording or listening to underwater sound.

-ost hydrophones are based on a pie'oelectric transducer thatgenerates electricity when sub#ected to a pressure change. 7hydrophone converts acoustic energy into electrical energy andis used in passive underwater systems to listen only.

+ydrophones are usually used below their resonance fre(uencyover a much wider fre(uency band where they provide uniformoutput levels 1?igure D.H2. Such pie'oelectric materials ortransducers can convert a sound signal into an electrical signal

since sound is a pressure wave in 8uids


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AN ARRA* O' H*DRO"HONES ASSEM($ED IN '$%ID

'I$$ED CA($E


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"ROCESSIN# O' HI#H RESO$%TION SEISMIC DATA

he ac(uired seismic re8ection data contains a lot of noise. hesenoises are removed by applying sophisticated processing techni(uesmostly with state"of"art seismicdata processing software package.

he basic ob#ective of all seismic processing is to convert the

information recorded in the !eld into a form that facilitates geologicalinterpretation.

he resultant processed data provides a structural image of the sub"surface which allows one to map sub"surface distribution of seismicse(uences depositional environments rock facies and structural trends.

he purpose of seismic data processing is to manipulate theac(uired data into an image that can be used to infer the sub"surface structure.

4rocessing consists of the application of a series of computerroutines to the ac(uired data guided by the processinggeophysicist


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SEISMIC RESO$%TION

VERTICA$RESO$%TION ,

seismic resolution is the ability to distinguish separatefeaturesK in other words the minimum distance betweentwo features so that the two can be identi!ed separatelyrather than as one feature. normally we think ofresolution in the vertical sense

HORI4ONTA$ RESO$%TION ,

+ori'ontal resolution refers to how close two re8ecting

points can be situated hori'ontally and yet berecogni'ed as two separate points rather than one. hearea that produces the re8ection is known as the ?irst?resnel Mone3 the re8ecting 'one in the subsurfaceinsoni!ed by the !rst (uarter of a wavelength. If thewavelength is large then the 'one over which there8ection returns is larger and the resolution is lower.


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+igh resolution shallow seismic section showing gas chargedsediment and


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GROUND PENETRATING RADAROR

GPR METHOD


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In'r(!&'i(n

Gr(n! +ene'ra'in* ra!ar 3&(mm(n)y &a))e! GPR4 i% a#i*# re%()'i(n e)e&'r(ma*ne'i& 'eni2e '#a' i%!e%i*ne! +rimari)y '( ine%'i*a'e '#e %#a))(/ %b%r$a&e($ '#e ear'#, bi)!in* ma'eria)%, an! r(a!% an! bri!*e%

Ge(+#y%i&a) e2i+men' %e% RADAR 3RA!i( De'e&'i(nAn! Ran*in*4 +)%e% $(r ima*in* %b%r$a&e

U%e% e)e&'r(ma*ne'i& ra!ia'i(n in '#e mi&r(/aeban!3?== MH '( ?== GH4 an! !e'e&'% '#e re$)e&'e!

%i*na)% $r(m %b%r$a&e %'r&'re%5Me!ia in&)!e% r(&0, %(i), i&e, $re%#/a'er, +aemen'% an!

%'r&'re%


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Hi%'(ry

T#e $ir%' %e ($ E)e&'r(ma*ne'i& %i*na)% '( )(&a'ebrie! (b.e&'% i% a''rib'e! '( H)%meyer in aGerman +a'en' in 67(85

T#e $ir%' +b)i%#e! !e%&ri+'i(n ($ % ine%'i*a'i(n%/a% by Leimba an! L(/y in 676= a*ain in German+a'en'%

T#e +('en'ia) ($ GPR $(r &ii)ian %e /a% i!en'i$ie!

by Ge(+#y%i&a) Srey Sy%'em% In&53GSSI4


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Utility Mapping Utility mapping using GPR

U'i)i'y Ma++in*

En*ineerin* a++)i&a'i(n% ($ GPR

I!en'i$yin* !i$$eren' )ayer% in %(i) r(&0 $i)) in *e('eni&a)


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I!en'i$yin* !i$$eren' )ayer% in %(i), r(&0, $i)) in *e('eni&a)ine%'i*a'i(n


53/79

Paemen' &(n!i'i(n !ia*n(%'i&%Ma++in* (i!% (r &ai'ie% benea'# r(a!%, +aemen'%


54/79

M(ni'(rin* '#e &(n!i'i(n ($ rai)/ay ba))a%'


55/79

De'ai)e! in%+e&'i(n ($ &(n&re'e %'r&'re%


56/79

In%+e&'i(n 2a)i'y ($ +re&a%' &(n&re'eDe'e&'i(n ($ 'ermi'e a''a&0 (ne% in 'imber

Ma++in* (ne% ($ 'ermi'e a''a&0 (r $n*a) !e&ay in

'ree%De'e&'i(n ($ $a)'% , $ra&'rin* ($ r(&0%3BH- GPR4

De'erminin* '#i&0ne%% ($ %n(/ an! i&e5

Ma++in* are()(*i&a) rin%

Sreyin* %e!imen'% benea'# b(''(m% an! )a0e% an!rier%


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Prin&i+)e% ($ (+era'i(n

A GPR in%'rmen' &(n%i%'%($ 1

A &(n'r() ni'

A re&(r!er

A 'ran%mi''in* an'ennaA re&eiin* an'enna


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An'ennaeBi%'a'i& (r M(n(%'a'i&m(!e

Fr(m $i*re1-

A5 Tran%mi''er an'enna3T4 Re&eiin*an'enna 3R4

B5 In'er+re'e! %e&'i(n

C5 Ra!ar*ram !i%+)ay


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An E)e&'r( Ma*ne'i& +)%ei% %en' '#r(*# '#ean'enna, +ene'ra'in* in'('#e %reye! ma'eria)5

A +(r'i(n ($ '#e ener*y i%re$)e&'e! ba&0 '( '#ean'enna /#en an in'er$a&ebe'/een ma'eria)% ($!i%%imi)ar !ie)e&'ri&

&(n%'an'% i% en&(n'ere!5


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An'enna an! Fre2en&y

Di$$eren' an'enna% +r(i!e!i$$eren' $re2en&ie%, /#i%a))y ary be'/een :> an!6,>== MH

L(/er $re2en&ie% +r(i!e

*rea'er !e+'# +ene'ra'i(nb' )(/er re%()'i(n

Hi*#er $re2en&ie% +r(i!e%#a))(/ !e+'# +ene'ra'i(nb' #i*# re%()'i(n5

Di%+)ay% are ('+' in 'erm%($ ariab)e area /i**)e (r/i**)e 'ra&e (n)y


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Re)a'ie Die)e&'ri& C(n%'an'

T#e Re)a'ie !ie)e&'ri& &(n%'an' 3 4 i% '#e ra'i( ($ '#e+ermi''ii'y ($ a %b%'an&e '( '#e +ermi''ii'y ($ $ree%+a&e5

Permi''ii'y, a)%( &a))e! e)e&'ri& +ermi''ii'y, i% a &(n%'an'

an! i% e2a) '( a++r(ima'e)y 5> 6=-6:

$ara! +er me'er3Fm4 in $ree %+a&e 3a a&m45

9 J 3656? 6=664

T#e e)(&i'y ($ ra!i( /ae in a ma'eria) i% *ien by

0

r

=

r

cVm

=

r

r


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Material r V(mm/ns)

Air 1 300

Water (fresh) 81 33

Water (sea) 81 33

Permafrost 1-8 106-300

Coastal sand (dry) 10 9

!and (dry) 3-6 1"0-1#0

!and ($et) "-30 -60

!ilt ($et) 10 9Clay ($et) 8-1 86-110

Clay soil (dry) 3 1#3

A%era&e 'soil 16 #

ranite -8 106-1"0

*imestone #-9 100-113

+asalt ($et) 8 106!andstone ($et) 6 11"

Con,rete 6-30 -11"

Ashalt 3- 13.-1#3

PC o2y Polyesters 3 1#3

Re)a'ie !ie)e&'ri& &(n%'an'% an! ra!i( /ae e)(&i'ie% $(r !i$$eren' ma'eria)%

*Data from Johnson et al. (199), !cCann et al. (19""), !ore# (19$), %e#nolds (199&,1991).


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T#e re$)e&'e! %i*na) #a%in$(rma'i(n (n1

#(/ 2i&0)y '#e %i*na) 'rae)e!

#(/ m /a% a''ena'e! T#e '#i&0ne%% ($ a )ayer i% *ien

by1

/#ere

dii% '#e '#i&0ne%% ($ )ayer i,

ti '#e '('a) 'rae) 'ime '#r(*# '#a'

)ayer,

c i% '#e %+ee! ($ )i*#' an!

'r,i '#e !ie)e&'ri& &(n%'an' ($ '#e

)ayer i

T#e am(n' ($ re$)e&'e!ener*y a' an in'er$a&e i%*(erne! by1

/#ere 1,) i% '#e re$)e&'i(n&(e$$i&ien' an! 'r1an! 'r)are'#e !ie)e&'ri& &(n%'an'%

"

i

ir

itc

d =

"1

"1"1

rr

rr

+

=


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Ra!i(/aee)(&i'ie% a% a$n&'i(n ($ re)a'ie Die)e&'ri&

&(n%'an'%


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Da'a A&2i%i'i(n

GPR %rey% are &(n!&'e!by +))in* '#e an'ennaa&r(%% '#e *r(n! %r$a&e a'a n(rma) /a)0in* +a&e5

T#e re&(r!er %'(re% '#e !a'a

a% /e)) a% +re%en'in* a+i&'re ($ '#e re&(r!e! !a'a(n a %&reen5

Re%()'i(n i% '#e mea%re ($abi)i'y '( !i%'in*i%#

be'/een '( a!.a&en' %i*na)%/#i !e+en!% +(n '#e$re2en&y ($ ra!i( /ae%

!


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Pr(&e%%in* an! In'er+re'in*

RADAN i% GSSI% *r(n! +ene'ra'in* ra!ar+r(&e%%in* %($'/are5

S'an!% $(r RA!ar Da'aANa)y%er

I' #a% been !ee)(+e! (er '#e )a%' := year% '( ai! in'#e +r(&e%%in* an! in'er+re'a'i(n ($ GPR !a'a5

Rn% (n re*)ar )a+'(+ (r !e%0'(+ &(m+'er

Pr(i!e% '#e %er /i'# many +(/er$) '(()% '( &)ean

+ an! ie/ !a'a in ?D


67/79


68/79

Ge()(*y re+re%en'e! in &()(r %&a)e /i'# Gain a)e ($


69/79


70/79

Fi )! i i


71/79

Fie)! i%i'

A near %#(re !a'a a&2i%i'i(n in '#e Man!(i Rieranne) /a% &arrie! (' (nb(ar!!+ hal-unibyCSIR- NIO, D(na Pa)a5

T#e %rey e%%e) )e$' $r(m Ca+'ain ($ P(r'%, Be'im(n ?r!N(ember :=68


72/79


73/79


74/79

S ! I $


75/79

Smmary an! In$eren&e%

T#i% %'!y &arrie! (' a' CSIR-NIO, G(a #a% +r(i!e! an! (++(r'ni'y '( a&2ire&(n%i!erab)e in$(rma'i(n an! 0n(/)e!*e in e( %(n!in*, %i!e %&an %(nar, %ei%mi&re$)e&'i(n an! *r(n! +ene'ra'in* ra!ar 'eni2e% /#i are ($ immen%e %e in*e('eni&a) en*ineerin*5 T#e /(r0%#(+ (n Gr(n! +ene'ra'in* Ra!ar #e)! in O&'(ber:=68 a' CSIR-NIO a)%( #e)+e! % '( n!er%'an! i'% /(r0in* +rin&i+)e% an! '#e a*en&ie%+r(i!in* GPR e2i+men'5

S(me ($ '#e in$eren&e% !ra/n $r(m '#e %'!ie% an! /(r0 &arrie! (' !rin* '#e +r(.e&''enre are )i%'e! be)(/1

E( %(n!in* 'eni2e i% $(n! '( be ery %e$) '( !e'ermine '#e /a'er !e+'# an!b(''(m '(+(*ra+#y ($ /a'er &(ere! area%

Si!e %&an %(nar 'eni2e i% %e! '( $in! (' (b.e&'% )yin* (n '#e %ea $)((r be$(re +)annin*&(n%'r&'i(n ($ any ($$%#(re %'r&'re % a% ($$%#(re +)a'$(rm%, .e''ie%, #arb(r!ee)(+men', n!er/a'er +i+e)ine $(r 'ran%+(r'in* (i) an! *a%, $re%# /a'er, e$$)en'

!i%ar*e e'&5 Hi*# re%()'i(n %#a))(/ marine %ei%mi& re$)e&'i(n me'#(! i% %e$) '( !e'ermine %ea $)((r

m(r+#()(*y , %b%r$a&e $ea're% an! n!er)yin* %#a))(/ %'ra'i*ra+#y $(r e&0in*$ea%ibi)i'y ($ %i'e $(r &(n%'r&'i(n ($ any ($$%#(re %'r&'re5

GPR &an be %e $(r ari(% en*ineerin* a++)i&a'i(n )i0e )(&a'in* 'i)i'y %eri&e%, !e'e&'i(n($ (i!% (r &ai'ie%, ma++in* be! r(&0 !e+'# (r $a)'% an! $ra&'re! (ne% in r(&05

R $


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Re$eren&e%

Br(/er, 5 an! He)bi*, K5 6775 S#a))(/ #i*#-re%()'i(n re$)e&'i(n %ei%mi&5 Han!b((0 ($*e(+#y%i&a) e+)(ra'i(n, ?76++5C#abey, A5K5, :=6:5 Ge(+#y%i&a) %rey ($$ Can!()im Bea, G(a reea)% )ar*e remnan' ($ a*r(n!e! e%%e)5 S(r&e - #''+1///5ni(5(r*ni(+)(a!ne/%?:


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D(brin, M5B5 67


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(#n%(n H5P5 He)$er'y M5 677=5 T#e Ge()(*i&a) In'er+re'a'i(n ($ Si!e-S&an S(nar5 Reie/%

($ Ge(+#y%i&%, :, ?>-?=5

Kin%)er, L5A5 C(++en%, A5 an! San!er%, 5 67:5 Fn!amen'a)% ($ A&(%'i&%5 Wi)ey an! S(n%,T(r(n'(

Pe'er, T5K5 6785 A++)ie! #i*#-re%()'i(n *e(+#y%i&a) me'#(!% ($$%#(re *e(en*ineerin*#aar!%5 In'erna'i(na) Hman Re%(r&e% Dee)(+men' C(r+(ra'i(n, 8?-> ++5

Reyn()!%, (#n M5 6775 Gr(n! Pene'ra'in* Ra!ar1 An In'r(!&'i(n '( A++)ie! an!Enir(nmen'a) Ge(+#y%i&%5 (#n Wi)ey S(n%, Reyn()!% Ge(-S&ien&e% L'!5, UK, ++5, U5S5 Army,C(r+% ($ En*ineer%, C(a%'a) En*ineerin* Re%ear Cen're, ++ ::5

"e)$, Riar! 5 :==5 A++)i&a'i(n ($ *r(n! +ene'ra'in* Ra!ar '( Cii) an! Ge('eni&a)En*ineerin*, E)e&'r(ma*ne'i& P#en(mena, , 66=-66


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THAN !OU

sounding,high resolution shallow seismic reflection and underwater sonographic

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