Blind ocean acoustic tomography and TOMPACO'

Blind Ocean Acoustic Tomography

presentation at the ENEA Workshop on

Ocean Acoustic Tomography: results and perspectives

28 November 2002

Santa Teresa, Lerici, It´

alia

by

S.M. Jesus and C.Soares

SiPLAB, FCT - Universidade do Algarve

Campus de Gambelas, PT-8000 Faro, Portugal

Blind

Ocean

Acoustic

T

omograph

y

S.M.

Jesus

and

C.

Soares

{

sjesus,csoares

}

@ualg.pt

SiPLAB,

F

CT

-Univ

ersidade

do

Algarv

e,

Campus

de

Gam

b

elas,

PT

-F

aro,

P

ortugal

Supp

orted

under

A

TOMS,

F

CT

con

tract

PDCTM/P/MAR/15296/1999

and

TOMP

A

CO,

CNR,

Italy

.

Outline

•

the

game

of

the

name

and

motiv

ation

•

the

INTIF

ANTE’00

sea

trial

•

en

vironmen

tal

in

v

ersion

•

activ

e

tomograph

y

•

passiv

e

tomograph

y

•

summary

Ocean Acoustic Tomography - synoptic

Acoustic Model

p( )

ζ

ζ

r( )

y

ζ

ζ

environment

new

^

X

receiver

acoustic pressure

source signal

Correlator

Optimization

s(t)

(r,z)

source

Motiv

ation

⇒

•

decrease

the

dep

endency

on

source

kno

wledge

(emitted

signal

and

source

p

osition)

•

increase

the

(time-space)

adaptivit

y

•

abilit

y

to

use

non-co-op

erativ

e

(noise)

sources

INTIFANTE’00 Experimental Site

-9˚ 30' -9˚ 30' -9˚ 15' -9˚ 15' -9˚ 00' -9˚ 00' -8˚ 45' -8˚ 45' -8˚ 30' -8˚ 30' 38˚ 00' 38˚ 00' 38˚ 15' 38˚ 15' 38˚ 30' 38˚ 30' 38˚ 45' 38˚ 45' 39˚ 00' 39˚ 00' -9˚ 30' -9˚ 30' -9˚ 15' -9˚ 15' -9˚ 00' -9˚ 00' -8˚ 45' -8˚ 45' -8˚ 30' -8˚ 30' 38˚ 00' 38˚ 00' 38˚ 15' 38˚ 15' 38˚ 30' 38˚ 30' 38˚ 45' 38˚ 45' 39˚ 00' 39˚ 00' -9˚ 30' -9˚ 30' -9˚ 15' -9˚ 15' -9˚ 00' -9˚ 00' -8˚ 45' -8˚ 45' -8˚ 30' -8˚ 30' 38˚ 00' 38˚ 00' 38˚ 15' 38˚ 15' 38˚ 30' 38˚ 30' 38˚ 45' 38˚ 45' 39˚ 00' 39˚ 00' -9˚ 30' -9˚ 30' -9˚ 15' -9˚ 15' -9˚ 00' -9˚ 00' -8˚ 45' -8˚ 45' -8˚ 30' -8˚ 30' 38˚ 00' 38˚ 00' 38˚ 15' 38˚ 15' 38˚ 30' 38˚ 30' 38˚ 45' 38˚ 45' 39˚ 00' 39˚ 00' -9˚ 30' -9˚ 30' -9˚ 15' -9˚ 15' -9˚ 00' -9˚ 00' -8˚ 45' -8˚ 45' -8˚ 30' -8˚ 30' 38˚ 00' 38˚ 00' 38˚ 15' 38˚ 15' 38˚ 30' 38˚ 30' 38˚ 45' 38˚ 45' 39˚ 00' 39˚ 00' INTIFANTE’99 Area

LISBON

Sesimbra

Setubal

Espichel Cape

Ge

ome

tr

y

and

Bath

yme

tr

y

V

er

ti

ca

l

Line

A

r

ra

y

Radio

Buo

y:

depl

o

yme

n

t

and

se

tup

Reco

v

er

ing

the

T

e

lem

et

ry

U

ni

t

Sound

so

urce

and

e

mit

te

d

si

gnal

s

Ev

en

ts

2

a

nd

5

:

bat

h

ym

etr

y

and

runs

T

emp

erat

ure

ev

o

lut

io

n

(XB

T

)

Em

pir

ical

Ort

hogo

nal

F

uncti

ons

c

EOF

=

ˆc

+

N

X

n

=1

α

n

u

n

ˆN

=

mi

n

N

{

P

N

n

=1

λ

2

n

P

M

m

=1

λ

2

m

>

0

.8

}

1506

1510

1515

0

20

40

60

80

100

119

Soundspeed (m/s)

Depth (m)

−0.2

−0.1

0

0.1

0

20

40

60

80

100

119

Soundspeed (m/s)

Depth (m)

1st EOF

2nd EOF

P

h

ysical

mo

del

-NW/

N

E

tr

a

c

k

0

60

119

Depth (m)

Range (km)

Source (63 m)

Sediment

Subbottom

0

2

5.7

1506

1518

m/s

2.0 m

1750 m/s

α

=0.8 dB/

λ

ρ

=1.9 g/cm

3

α

=0.8 dB/

λ

ρ

=1.9 g/cm

3

1800 m/s

VA

Inversion results for Event 2

289.580 289.6 289.62 289.64 289.66 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Julian Time Bartlett Power 289.58 289.6 289.62 289.64 289.66 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 Julian Time Range (km) 289.58 289.6 289.62 289.64 289.66 10 20 30 40 50 60 70 80 90 100 Julian Time Depth (m) 289.5885 289.6 289.62 289.64 289.66 86 87 88 89 90 91 92 93 94 95 Julian Time Sensordepth (m) 289.58 289.6 289.62 289.64 289.66 1520 1540 1560 1580 1600 1620 1640 1660 1680 1700 Julian Time Speed in sed. (m/s) 289.58 289.6 289.62 289.64 289.66 2 4 6 8 10 12 14 Julian Time Sediment thickness (m) 289.58 289.6 289.62 289.64 289.66 1550 1600 1650 1700 1750 1800 1850 1900 Julian Time Speed in sub−bottom (m/s) 289.58 289.6 289.62 289.64 289.66 −0.03 −0.02 −0.01 0 0.01 0.02 0.03 0.04 Julian Time

Array tilt (rad)

289.58 289.6 289.62 289.64 289.66 −20 −15 −10 −5 0 5 10 15 20 Julian Time α1 289.58 289.6 289.62 289.64 289.66 −20 −15 −10 −5 0 5 10 15 20 Julian Time α2

P

h

ysical

mo

del

-NW/

N

E

tr

a

c

k

0

60

119

Depth (m)

Range (km)

Source (63 m)

Subbottom

0

2

5.7

1506

1518

m/s

α

=0.8 dB/

λ

ρ

=1.9 g/cm

3

1800 m/s

VA

Sediment

2.0 m

1650 m/s

α

=0.8 dB/

λ

ρ

=1.9 g/cm

3

Inversion results for Event 5

290.94 290.96 290.98 291 291.02 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Julian Time Bartlett Power 290.94 290.96 290.98 291 291.02 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 Julian Time Range (km) 290.94 290.96 290.98 291 291.02 10 20 30 40 50 60 70 80 90 100 Julian Time Depth (m) 290.94 290.96 290.98 291 291.02 85 86 87 88 89 90 91 92 93 94 95 Julian Time Sensordepth (m) 290.94 290.96 290.98 291 291.02 1520 1540 1560 1580 1600 1620 1640 1660 1680 1700 Julian Time Speed in sed. (m/s) 290.94 290.96 290.98 291 291.02 2 4 6 8 10 12 14 Julian Time Sediment thickness (m) 290.94 290.96 290.98 291 291.02 1550 1600 1650 1700 1750 1800 1850 1900 Julian Time Speed in sub−bottom (m/s) 290.94 290.96 290.98 291 291.02 −0.03 −0.02 −0.01 0 0.01 0.02 0.03 Julian Time

Array tilt (rad)

290.94 290.96 290.98 291 291.02 −20 −15 −10 −5 0 5 10 15 20 Julian Time α1 290.94 290.96 290.98 291 291.02 −20 −15 −10 −5 0 5 10 15 20 Julian Time α2

Ti

de

ev

ol

uti

on

and

V

A

m

o

ving

Est

im

a

ted

temp

er

a

ture

pro

files

-Ev

en

t

2

&

5

13

14

15

16

17

18

0

20

40

60

80

100

120

Temperature (

o

C)

Depth (m)

XBT

Thermistors

13

14

15

16

17

18

0

20

40

60

80

100

120

Temperature (

o

C)

Depth (m)

XBT

Thermistors

NRP

D.

Car

lo

s

I

Ov

eral

l

leng

th

(m

)

68

Be

a

m

(m)

13

Gross

di

sp

la.

(ton)

28

00

Tw

o

di

esel-elec

tric

(HP

)

80

0

Max

sp

eed

(kn)

11

Crew

34

Scien

tific

15

Ev

en

t

6

:

bat

h

ym

etr

y

and

so

urce

r

un

Depth (m)

70

80

90

100

110

120

130

124

126

128

130

132

134

149

150

151

152

153

x

Event 5 − NE leg

x

ULVA

x

x

Militar Long. (km)

02:14

03:14

02:44

Event 6

02:59

x

x x x xx

x

Event 2 − NW leg

Militar Lat. (km)

NRP D. Carlos I speed and heading

291.09

0

291.1

291.11

291.12

291.13

291.14

291.15

291.16

2

4

6

8

10

12

14

Ship speed (kn)

(a)

291.09

0

291.1

291.11

291.12

291.13

291.14

291.15

291.16

100

200

300

400

Bearing (deg)

Julian date

(b)

P

h

ysical

mo

del

a

nd

sear

c

h

par

amet

er

s

0

60

119

Depth (m)

Range (km)

Source (3 m)

Sediment

Subbottom

0

2

5.7

1506

1518

m/s

2.0 m

1650 m/s

α

=0.8 dB/

λ

ρ

=1.9 g/cm

3

α

=0.8 dB/

λ

ρ

=1.9 g/cm

3

1800 m/s

VA

Sym

b

ol

U

nit

Searc

h

in

t./

Steps

α

1

m/s

-20

20

64

α

2

m/s

-20

20

64

sr

km

0.

5

3.

5

6

4

sd

m

1

10

3

2

rd

m

85

95

3

2

θ

rad

-0.

03

0.

03

32

NRP

D.

Car

lo

s

I

r

adiat

ed

noi

se

dB

180

185

190

195

200

205

Frequency (Hz)

Julian Time

100

200

300

400

500

600

700

291.1

291.105

291.11

291.115

291.12

291.125

100

200

300

400

500

600

700

185

190

195

200

205

Frequency (Hz)

Power (dB)

291.1

291.107

291.114

291.121

291.128

291.135

200

300

359

400

500

600

700

Julian Time

Frequency (Hz)

Inversion results for Event 6

291.102 291.11 291.118 291.126 291.134 0 0.2 0.4 0.6 0.8 1 Julian Time Bartlett Power 291.102 291.11 291.118 291.126 291.134 0.5 1 1.5 2 2.5 3 3.5 Julian Time Range (km) 291.102 291.11 291.118 291.126 291.134 1 2 3 4 5 6 7 8 9 10 Julian Time Depth (m) 291.102 291.11 291.118 291.126 291.134 85 90 95 Julian Time Sensordepth (m) 291.102 291.11 291.118 291.126 291.134 −0.03 −0.02 −0.01 0 0.01 0.02 0.03 Julian Time

Array tilt (rad)

291.102 291.11 291.118 291.126 291.134 −20 −15 −10 −5 0 5 10 15 20 Julian Time α1 291.102 291.11 291.118 291.126 291.134 −20 −15 −10 −5 0 5 10 15 20 Julian Time α2

1504

1506

1508

1510

1512

1514

1516

291.102 291.11 291.118 291.126 291.134

0

20

40

60

80

100

Julian Time

Depth (m)

Theoretical

bac

kground

•

Linear

broadband

data

mo

del:

Y

(θ

0

₎

=

[Y

T

(ω

1

)·

··

Y

T

(ω

L

)]

T

=

H

(θ

0

)S

+

U

•

Minim

um

variance

signal

estimator:

ˆS(

ˆθ

0

₎

=

[(

H

H

( ˆθ

0

)H

( ˆθ

0

_)]

−

1

H

H

( ˆθ

0

₎

N

−

1

X

n

=0

Y

n

(θ

0

₎

•

Broadband

con

ven

tional

pro

cessor:

P

inc

(θ

)

=

K

X

k

=1

| ˆS

(ω

k

)|

2

H

H

(ω

k

,θ

)

ˆC

Y

Y

(ω

k

,ω

k

)H

(ω

k

,θ

)

k

H

(θ

)

ˆS

k

₂

F

requency

selection

•

V

ariance

at

the

k

th

hydrophone:

V

(ω

,k

)

=

1

T

Z

T

0

[Y

(ω

,t,

k

)

−

µ

Y

(ω

,k

)]

2

dt,

•

Lik

eliho

od

measure:

v

(ω

)

=

K

K

X

k

=1

V

(ω

,k

)

200

300

400

500

600

700

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Frequency (Hz)

Likelihood

Ev

en

t

6:

In

v

ersion

results

291.112 291.117 291.123 291.128 291.134 0 0.2 0.4 0.6 0.8 1

Julian Time

Bartlett Power 291.112 291.117 291.123 291.128 291.134 0.5 1 1.5 2 2.5 3 3.5

Julian Time

Range (km) 291.112 291.117 291.123 291.128 291.134 1 2 3 4 5 6 7 8 9 10

Julian Time

Depth (m) 291.112 291.117 291.123 291.128 291.134 85 90 95

Julian Time

Sensordepth (m) 291.112 291.117 291.123 291.128 291.134 −0.03 −0.02 −0.01 0 0.01 0.02 0.03 Julian Time

Array tilt (rad)

291.112 291.117 291.123 291.128 291.134 −20 −15 −10 ₋₅ 0 5 10 15 20

Julian Time

α₁ 291.112 291.117 291.123 291.128 291.134 −20 −15 −10 ₋₅ 0 5 10 15 20

Julian Time

α₂ 13 14 15 16 17 18 0 20 40 60 80 100 Temperature o C Depth (m) in focus off focus XBT

Ev

en

t

6:

Ship

p

o

w

er

sp

ectrum

estimation

200

300

400

500

600

700

291.11

291.115

Julian Time

291.12

291.125

291.13

Frequency (Hz)

270 359 719

Summary

This

is

a

preliminary

test

for

ship

noise

tomograph

y

in

a

(assumed)

unkno

wn

en

vironmen

t.

•

strong

correlation

b

et

w

een

ship

sp

eed/emitted

p

ow

er

and

accurate

source

trac

king

•

when

in

fo

cus

geometrical

and

en

vironmen

tal

parameter

assume

credible

values

→

more

extensiv

e

data

for

oceanographic

features

observ

ation

→

enhanced

searc

h

of

ship

noise

sp

ectral

comp

onen

ts