1

Time Frequency Analysis

Application - Radar

電機四 B99901084 林晉毅2013.12.12

2

Outline• Introduction

o Radar Signalo Range Profile

• Time-Frequency Analysis of Radar Range Profileso Time-Frequency Representation of Range Profiles

• Time-Frequency-Based Radar Image Formationo Fourier-Based Radar Image Formationo Time-Frequency-Based Radar Image Formation

3

Introduction• RADAR(Radio Detection and Ranging)

4

Introduction

•

5

Introduction• Scattering

6

Radar Signal• Linear Frequency Modulated Signal(LFM)

o f0 ： carrier frequencyo ： frequency-changing rate or chirp rateo α ： determines the width of the Gaussian envelope

7

Radar Signal

8

Radar Signal• Stepped Frequency Signal(SF)

o TPRI ： Pulse Repetition Intreval

9

Radar Signal

10

Range Profile• Range Profile ： a range-compressed back-

scattered signal - the distribution of target reflectivity along the radar line of sight (LOS) to the target, provided target information about target length and position of strong scatterers.

11

Cross Range Profile• Cross Range ： the dimension transverse to the

radar LOS

• Doppler Profile Cross Range Profile• 2D ： Range-Doppler Profile Range-Cross Range

Profile(knowing scaling factor ： rotation rate & λof transmitted signal)

12

Doppler Profile

13

Time-Frequency Analysis of Radar Range Profiles

14

Time-Frequency Representation of Range Profiles

15

Time-Frequency Representation of Range Profiles

16

Time-Frequency Representation of Range Profiles

13.1GHz

17

Time-Frequency Representation of Range Profiles

TE10

TE20

18

Time-Frequency-Based Radar Image Formation

19

Fourier-Based Radar Image Formation

20

Time-Frequency-Based Radar Image Formation

21

Time-Frequency-Based Radar Image Formation

22

Thank You For Your Attention