Bożena Kunka Tutor: dr inż.. Jan Matuszewski

The Application of Neural The Application of Neural Networks in Radar Signals Networks in Radar Signals

RecognitionRecognition

NNeural eural NNetworks - etworks - applicationapplication

Construction of a arificial neuron bases on biological nerve cell

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Issues of recognition are currently the most often used of neural networks application

1. 1g

Applying the neural networks in radioelectronics gives enormous possibilities of real-time information processing

McCulloch-Pitts Neuron Model

x1

xn

y f

w1

wn

e

),,....,( n21 xxxx input values

(signals) vector

),...,,( n21 wwww

weighted coefficients vector

n

iiiwxe

1

total neuron excitation

)(efy

signal value at the neuron’s output

neuron activation function

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Neuron activation functions

linear function sigmoidal function step function

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-0,5

0

0,5

1

1,5

-1 -0,5 0 0,5 1

Single step function

Sigmoidal function

Linear function

Multilayer Perceptron

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Learning the Neural Networks

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with a teacher

without a teacher

- basing on the learning set the network learns the proper operation

- applied when the network responses are not known

Minimum Distance Method Of Signal Recognition

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),(min),(,...,2,1

jiLj

ji XXdXXd

x1

x2

iX

- radiation source class

jX

- measure vector

Neural Network and Classic Method Of Signal Recognition

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the quantity of klass: L=10

the quantity of parametres: L=10

2,0 standard deviation:

The quantity of realizations for each class: n=100

NEURAL NETWORK: - THREE-LAYER PERCEPTRON- 10 SUBNETWORKS

CLASSIC METHOD: - MINIMUM DISTANCE CLASSIFIER

Number Of Correct Classifications

Stand.Dev. σ=0,2 σ=0,3 σ=0,6

SIGNALCLASS S.S.N.

M. M-O. S.S.N.

M. M-O.

S.S.N.

M. M-O.

1 1000 988 1000 790 911 158

2 1000 985 985 771 823 131

3 1000 988 1000 799 942 138

4 1000 985 1000 785 974 169

5 1000 984 1000 802 914 144

6 1000 988 994 787 870 148

7 1000 985 999 803 883 150

8 1000 984 1000 803 1000 145

9 1000 989 1000 794 996 120

10 1000 985 1000 778 977 146N.N. – Neural Network

ST.R. – Minimum Distance Method

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Probability Of Correct Classification

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NEURAL NETWORK

CLASSIC METHOD

Summary

Use of neural networks instead of classic method for radar signals recognition is more effective

Modular network structure makes its development quick and easy

Application of the neural networks

- promising

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