Space Time Matched Field Processing Matched Field Processing ...

photohomoeopathAI and Robotics

Nov 24, 2013 (3 years and 9 months ago)

99 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.