Space Time Matched Field Processing Matched Field Processing ...

photohomoeopathAI and Robotics

Nov 24, 2013 (3 years and 11 months ago)

107 views

Yung P. Lee

(ASAP 2001, March 14, 2001)


Science Applications International Corporation

1710 SAIC Drive


McLean, VA 22102

Yung@osg.saic.com


S
pace
-
T
ime
A
daptive
M
atched
-
field
P
rocessing
(STAMP)






1
0
/
)
sin(
2
Array

Line
Linear
)
(
)
(
N
n
c
nfd
i
e
nd
x
B






dt
e
t
x
f
X
ft
i

2
)
(
)
(
Fourier Transform Spectral (Frequency) Content

Sonar Signal Processing Background











1
0
2
)
(
)
(
)
(
N
n
t
nf
i
e
t
n
x
t
x
FFT
f
X

Spatial Beamforming Direction (Angle) of Arrival (DOA)







1
0
)
(
)
(
)
(
N
n
i
n
e
x
B
r
k
r


Matched Field Processing

Matched Field Processing 3D (Range,depth, bearing) Localization

*
1
0
1
)
,
(
)
,
(
)
,
,
(













N
n
ik
M
m
s
n
m
n
n
s
s
s
n
s
m
e
z
z
a
z
x
z
r
B
r
r
r

p
c
t
p
2
2
2
2




iwt
ik
M
m
s
m
s
m
m
s
s
e
e
k
z
z
a
z
z
p
s
m
r
r
r
r
r
r





1
)
(
)
(
2
)
,
;
,
(



0
]
)
(
[
2
2
0
2
2



m
m
m
k
z
k
dz
d


r
r
r
r




s
m
ik
M
m
s
m
s
s
e
z
z
a
z
z
p
1
)
,
(
)
,
;
,
(
Matched Field Tomography Modal Information Environmental Info.





m
m
s
s
s
s
s
s
a
k
z
r
B
z
r
,

w.r.t.
)
,
,
(
max

;
,
,

Given


Synthetic Aperture Matched Field Processing
















1
0
*
1
)
,
(
)
(
)
,
,
(
N
n
ik
M
m
s
n
m
s
n
s
s
s
n
s
m
e
z
z
a
t
n
v
r
x
v
z
r
B
r
r
source at 76 m towed at 2.5 m/s from 9.18 km

Space Time Matched Field Processing

Matched Field Processing





1
0
*
)
,
;
,
(
)
,
(
)
,
,
(
N
n
s
s
n
n
n
n
s
s
s
z
z
p
z
x
z
r
B
r
r
r

Space Time Matched Field Processing









1
0
*
)
,
;
,
(
)
,
(
)
,
,
(
N
n
s
s
n
n
n
n
s
s
s
z
z
t
n
p
t
n
z
x
z
r
B
r
v
r
v
r

Localization & Doppler (velocity) Discrimination
















1
0
*
)
,
;
,
(
)
,
(
)
,
,
,
(
N
n
s
s
n
n
t
n
n
t
s
s
s
s
z
z
t
n
p
t
n
z
x
v
z
r
B
r
v
r
v
r

Phone
-
Doppler Space

Beam
-
Doppler Space





)
,
;
,
(
)
,
(
)
,
,
,
(
*
s
s
n
n
t
n
n
t
s
s
s
s
z
z
t
n
p
t
n
z
x
v
z
r
B
n
n
r
v
r
v
r
r
r











BACKGROUND/OBJECTIVE


Space
-
Time Adaptive Processing (STAP) coherently combines
signals from the elements of an array and the multiple snapshots of
signals, to achieve large spatial/temporal signal gain, to suppress
interference, and to provide target detection in azimuth and velocity.



Matched
-
field processing (MFP) coherently combines complex
multi
-
path arrivals, to recover signal multi
-
path spreading loss and
to provide range/depth localization.



STAMP combines STAP and MFP to improve detection and
localization performance for the mobile multi
-
line
-
towed
-
array sonar
systems.

Azimuth (deg)

0







90







180

Doppler (Hz)

-

f
max

0

f
max

Doppler (Hz)

-

f
max

0

f
max

Target

Target

Clutter (Bottom Bounce)

Jammer

Jammer

(own
-
ship)

FWD

AFT

STAP


Detect the dot

Null the Jammer and the slanted clutter

STAMP


Detect/combine/class/localize the dots

Null the Jammer and the clutter

Passive

Forward
-
sector processing

C
m
,

f
m


f
m
=f
0
*v/c
m

Higher Mode (Path,Angle), Larger c
m


Larger c
m
,
Higher Angle (off horizontal), Smaller Doppler

C
1
,

f
1

Multi
-
path Doppler/Angle Spread

OUTLINE


STAMP Processing



Simulation scenario for forward
-
sector processing



Simulation Results

B
r
(f
0
)

Beam
-
space
replica

(Selected Beams
and Dopplers)

Phone 1

Line 1
x
11
(t)

Phone n

Line 1
x
n1
(t)


Doppler


Processing

X
1
(f)



Conventional
Beamforming

B
1
(f)




B(f)

Beam
-
Space
Vector

(selected Beams

and Dopplers)





WB/NB

Adaptive

MFP



Doppler


Processing

X
r

(f)




Conventional
Beamforming

B
r
(f)


Phone 1

Line k
x
1k
(t)

Phone n

Line k
x
nk
(t)


Doppler


Processing

X
k
(f)



Conventional
Beamforming

B
k
(f)



Propagation Code
to generate
Replica

x
r
(t)

Output

Ambiguity

Surface

R,Z
, ,
v

S
pace
-
T
ime
A
daptive
M
atched
-
field
P
rocessing (STAMP)

Search

R,Z
, ,
v


Forming

Covariance

Matrix

R = < B(f)
B
+
(f)>
f

&

Decomposition


B(f) = [B
1
(f)…. B
1
(f+m

f),…….., B
k
(f)…. B
k
(f+m

昩f

B
k
(f) = [b
k
(f,

1
)…… b
k
(f,

l
)]

AEL

Environ.

*
Plane
-
wave ~ STAP

Adaptive Processing

)
1
(

w.r.t.
Minimize





W
W
RW
W
W

S
A
R
A
A
R
W
1
1




A
R
A
1



1
S
Adaptive Weight Vector

Adaptive Output

**
A is the steering vector

**R is the measured covariance


matrix

t
t
t
)
(
)
(


x
x
R
High resolution

Sidelobe suppression

Subject to mismatch


Robust Methods

(widen the peak)

Wideband
-
Narrowband (
WB/NB
)

Feedback
-
Loop White
-
Noise
-
Constrained (
FLWNC
)

Adaptive Processing

B
r
(f
0
)

Beam
-
space
replica

(Selected Beams
and Dopplers)


Covariance Matrix

R
= <
B
(f)
B
+
(f)>
f

&

Decomposition






V
V
λ
n
n
n
n
R



B
R
B
B
R
B
B
R
r
1
r
r
1
r
r
1
1
S
w







δ
w
2
1
2













B
R
B
B
R
R
B
B
R
B
B
R
r

1
r

r

1
1
r

r

1
r

r

1
R
S
w




















2
δ
w
2

2

2


Adaptive

weight

W

V
V
λ
R
n
n
n
n
1
-
1



yes


= s

yes


㴠=

no

no

WB/NB

Processing

S(f)=W
+
B(f)

*
B(f) is “narrowband” (single f)


R and W are “broadband” (averaged over band of f)

Simulation Geometry (F=200 Hz)


target(NB)=120 dB, own
-
ship(BB)=120 dB, bottom bounce(BB)=115 dB

WNL=70 dB, 0.1


牡湤r洠灨慳攠敲e潲


歴k


歴k

瑯敤e
慲a慹

潷n
-
獨楰
湯楳i

扯瑴潭b
扯畮捥

㄰1


ㄸ㠠
m

卩湧汥
-
䱩Le

4
-
䱩Le
-
卥煵敮楡i

4
-
䱩Le
-
V敲瑩捡e

乯N敮e楲潮i敮瑡氠
mismatch

Single
-
Line BTRs of Each Signal Component

Forward Endfire at 0
o


Own
-
Ship Noise

Bottom Bounce

Target

__
Own
-
ship

__ Bottom Bounce

__ Target

Responses at 10
o

Azimuth

Single
-
Line Doppler/Azimuth Responses


integration time =256
-
sec, Target Range=10 km, Forward Endfire at 0
o


Own
-
Ship Noise

Bottom Bounce

Target

__
Own
-
ship

__ Bottom Bounce

__ Target

Selected beams
(0
o
-
30
o
) &
Dopplers (6 bins
for 6
-
kt search)

Responses at 10
o

Azimuth

Single
-
Line Beam/Cell Spectrograms

Conventional Plane
-
Wave (10
o
)

Adaptive Plane
-
Wave (10
o
)

Adaptive MFP (target track)

__
Adaptive PW

__ Adaptive MFP

Peak Level over Dopplers


Adaptive Beam/Cell Spectrograms

Adaptive Plane
-
Wave (10
o
)

Single Vertical Adaptive MFP

4_
Line_Vertical Adaptive MFP

__
PW

__ Single Line MFP

__ 4_Line_Vert MFP

Peak Level over Dopplers

Single Line, Conventional MFP

4_
Line_Sequential, Adaptive MFP

4_
Line_Vertical, Adaptive MFP

Single Line, Adaptive MFP


Array Size Dependence of MFP Range Tracking


search at target depth and target speed

Depth Discrimination of Adaptive MFP Range Tracking


4_Line_Vertical Array search at target speed

Depth=10 m

Depth=180 m

Depth=90 m

Depth=60 m

Speed= 3 m/s

Speed=
-
3 m/s

Speed=
-
1 m/s

Speed= 1 m/s

Speed Discrimination of Adaptive MFP Range Tracking


4_Line_Vertical Array search at target depth

SUMMARY



STAMP processing that combines STAP and MFP has been
developed.



Simulations show that STAMP coherently combines signal multi
-
path spread in azimuth and Doppler and greatly enhances target
detection as well as providing target range and depth
classification and localization.