T G Kostis 3D Multi-layer Modelling for ISAR

UNIVERSITY OF THE AEGEAN 11th Panhellenic Conference on Informatics (PCI 2007), Patras, Greece.

THREE-DIMENSIONAL MULTIPLE LAYER EXTENDED TARGET MODELING FOR INVERSE SYNTHETIC APERTURE RADAR STUDIES IN TARGET IDENTIFICATION Presented by Theodoros Kostis PhD Candidate, Dept of Information & Communication Systems Engineering University of the Aegean, Karlovasi, 83200 Samos, Greece.

[18-20 of May 2007]

1 Introduction - Project Purpose Correct stereoscopic (three-dimensional) Identification Friend or Foe (IFF) automatic decision on a non-cooperative and very likely hostile target Contact will generally be unable to fire upon the illuminating radar due to the great distance and technology gap between the two adversaries. [enemy inability to secure a good lock on friendly radar]

2 Non-Cooperative & Stealthy Targets Optical Countermeasures - Camouflage

2.1 Need for Positive Identification Background : Janes on Non-Cooperative Target Identification Rules of Engagement (ROEs)

• F-22 : 90% ability deprivation • F-15 : IFF+NCTRecon modes resulting in majority of air-to-air engagements • F-18 : NTCR but no IFF • F-14 : IFF but no NCTR (needed AWACS clearance) Jane’s International Defence Review – June 01, 2001

2.2 Need for Positive Identification Microwave Domain

3 Target Classification Theory Main Methods Available • • • •

HRR – High Range Resolution Profiling ISAR – Inverse Synthetic Aperture Radar JEM – Jet Engine Modulation Comb HRR-JEM – Combined HRR & JEM

3.1 Focus on HRR & ISAR Radar Parameters

Movement Engine

STX(n,t)=Aeφ

Environment Model

Exciter

Target

Antenna Range Delay Delay 2Ro/c

SRX(n,t)=σeφ-Range Delay Windowing (Reduces Range Side-lobes)

MIXER Pulse Compression - Matched Filter Function - Dechirp

SREF(n,t)=eφ-Delay

SIF(n,t-nT)=σeφ-Range Delay-Dechirp

Low Pass FIltering for A/D Help

Analog to Digital Conversion

N 1 K 1

S DIG (n, k )    ( e ( n ,k ) ) n 0

k 0

Recorder

Target RCS (σ) vs Range Delay

3.2 Organisation Model for Radar Systems Design 3D Engine System Dynamics

Radar Platform

Matched Filter

Transmitter Type ie Tx Parameters Waveform Selection

correlation convolution procedures

Target Platform

Motion Provider

Antenna Type ie phased array parabolic

Ground Clutter and other clutter types

Electromagnetic Interference

Propagation of Radar Waves Modeling ie. Parabolic - Ray Tracing Hybrid - Custom - Custom Hybrid [Refraction - Diffraction]

Motion Provider

Target Type ie. rcs

All Other Noise ie. equipment noise

Dynamic Errors

Receiver Type

ie. Platform Motion Scanning Motion Vibration

Glint

Directional Interference ie. Jammer Chaff

ie Rx Parameters

General Simulation Parameters Information Extraction from Signals Received

Results Formation

ie Code Specific Considerations Sampling Rate

4 Worldspace - Simulation Geometry z

Pace Engine [Affine Transformations]

Height Range Axis

Radar Sensor

φ2

φ1 Scatterer Aejφ (x1,y1,z1)

n 1

Scatterer Aejφ (0,0,0)

R1 R2

1 θ1 θ2

45

R

y Cross Range Axis

x Slant Range Axis

Entity-Relationship [Database Approach]

4.1 Data Format Radar Line of Sight LOS

Resolution Cells Inclusion for ISAR Calculations

RS 20

X axis

RS 15

141

136

131

126

121

116

111

106

101

096

091

086

081

076

071

066

142

137

132

127

122

117

112

107

102

097

092

087

082

077

072

067

143

138

133

128

123

118

113

108

103

098

093

088

083

078

073

068

144

139

134

129

124

119

114

109

104

099

094

089

084

079

074

069

145

140

135

130

125

120

115

110

105

100

095

090

085

080

075

070

061

056

051

046

041

062

057

052

047

042

036

031

026

021

016

011

006

001

037

032

063

058

053

048

043

038

033

027

022

017

012

007

002

028

023

018

013

008

003

064

059

054

049

044

039

034

029

024

019

065

060

055

050

045

040

035

030

025

020

014

009

004

015

010

005

RS 10 RS 05 z axis

x axis

RS 01 45o

Y axis y axis

RADAR

Z axis

5 Target Modeling Considerations Reflectance Model principles : the ship is divided into one hundred and forty-five (145) square equal cells.

Each of these cells produces an echo back at the radar which is modelled as a complex number (amplitude and phase) as shown in the equation below :

Reflectance Cell = RF

j IP e

5.1 DKMS Bismarck Upper Layer

5.2 DKMS Bismarck Lower Layer

6 Results The simulation provides : • a three dimensional environment.

• a multiple scatterers multiple layer mathematical representation of a large naval vessel.

• an entity-relationship description of the aforementioned model.

• plus a pace engine that can provide movement of objects within the worldspace.

6.1 Slant Range Profiles

6.2 Inverse Synthetic Aparture Radar

6.3 HRR & ISAR Association TARGET SLANT RANGE PROFILE - FREQUENCY DOMAIN SIGNATURE

TARGET SLANT RANGE PROFILE - TIME DOMAIN HISTORY

h/θ amplitude/phase of the nth slant range cell of the synthetic range profile from the kth burst

Η/φ amplitude/phase of I and Q echo samples from the ith step of the kth burst Steps from 1 to i Bursts from 1 to k

RESULTS

Steps from 1 to n

PULSE 01

PULSE 02

PULSE 33

H/ˆ(1,1)

H/ˆ(1,2)

H/ˆ(1,33)

SLANT RANGE CELL 01

SLANT RANGE CELL 02

SLANT RANGE CELL 33

h/Ë(1,1)

h/Ë(1,2)

h/Ë(1,33)

E1 MULTILAYER MODEL - SRP Ant 1 (32)

4

2.5

BURST 1

-1

FFT

x 10

2

Reflectance Value

1.5

1

0.5

H/ˆ(32,2)

H/ˆ(32,33)

FFT-1

h/Ë(32,1)

h/Ë(32,2)

h/Ë(32,33) 0 0

FFT

FFT

FFT

RD(1,1)

RD(1,2)

RD(1,33)

5

TARGET SLANT RANGE PROFILE - PHYSICAL DOMAIN

10

15 20 Resolution Cell ID

25

30

35

E1 MULTILAYER MODEL - ISAR Ant 1 (32)

5

7

x 10

6 5

Catalina distance is 45 Km from target.

Aspect Angle is 45 degrees.

Radar Sweep

4 Doppler

H/ˆ(32,1)

Steps from 1 to j

BURST 32

3 2

1

RD(32,1)

RD(32,2)

RD(32,33)

0

-1 0

FFT

FFT

FFT

RESOLUTION CELL 01

RESOLUTION CELL 02

RESOLUTION CELL 33

ISAR IMAGE - DOPPLER (HEIGHT) vs RESOLUTION CELLS

5

10

15 20 Resolution Cell ID

25

30

35

RD magnitude of the nth slant range cell and the jth doppler cell of the Range-Doppler image.

6.4 Vessel Height Ideal Case Resolution Cells vs Doppler 5

5

4

2.5

x 10

7

x 10

7

2

6

6

1.5

5

5

1

4

4

0.5

3

3

2

2

1

1

0

0

0

0

5

10

15

20

25

30

x 10

35

3 8 0 m m L 4 8 ,5 g ro o v e s , c a l. 5 2 o v e ra ll (1 4 ,9 6 " ) c a lib e r S K C /3 4

-1

-1 0

5

10

15

20

25

30

FuM O 23 (F u n k M e s s O rtu n g s g e ra te )

1 5 0 m m /L 5 5 (5 ,9 " ) S K C /2 8

35

0

5

10

15

20

25

30

35

6.5 Vessel Height Error Case Resolution Cells vs Doppler 5

4

2.5

x 10

7

x 10

4

2.5

x 10

2

2

6 1.5

1.5

5

1

1

0.5

4

0 0

0.5

3

5

10

15

20

25

30

35

5

10

15

20

25

30

35

5

7

x 10

6

0 0

5

10

15

20

25

30

35

2

5

4

3

1

380 mm L48,5 grooves, cal. 52 overall (14,96") caliber SK C/34

Usual Actual Result

2

1

0

0

-1 0

-1 0

5

10

15

20

25

30

FuMO 23 (FunkMess Ortungsgerate)

35

Not dependent on S/N 150 mm/L55 (5,9") SK C/28

Three-Dimensional Multiple Layer Extended Target Modeling for Inverse Synthetic Aperture Radar Studies in Target Identification

Are there any questions?

E-mail : tkostis@aegean.gr