Automated Road Extraction from Radar and Optical Imagery

Acknowledgements

Table of Contents

Table of  Contents  

1.  Introduction  8

1.1.  Motivation  8

1.2.  Goal and contents  9

2.  Radar systems  11

2.1.  Basic principles of radar systems  11

2.2.  Airborne and spaceborne radar systems  14

2.3.  Radar image properties  16

2.4.  Differences between radar and optical imagery  17

2.5.  Areas of application for radar images  19

3.  Extraction of linear objects from SAR and optical imagery  21

3.1.  Road models for SAR and optical imagery  21

3.1.1.  Road models for optical imagery  21

3.1.2.  Road models for SAR imagery  24

3.2.  Overview of extraction algorithms for linear features  25

3.2.1.  Unsupervised extraction for main road axes  25

3.2.2.  TU Munich road extraction  26

3.2.3.  Intermap road extraction  27

3.2.4.  Road extraction from interferometric SAR data  27

3.3.  Selection of algorithms for further examination  29

4.  Extraction algorithms  30

4.1.  Acquisition of global context  30

4.2.  Intermap extraction algorithm  31

4.2.1.  General approach  31

4.2.2.  Consideration of global context  35

4.2.3.  Adaptations for use with optical imagery  37

4.3.  TU Munich extraction algorithm  37

4.3.1.  General approach  38

4.3.2.  Consideration of global context  42

4.3.3.  Adaptations for use with SAR imagery  44

5.  Practical analysis of extraction algorithms on SAR imagery  46

5.1.  Intermap extraction algorithm on SAR imagery  46

5.1.1.  Test approach  46

5.1.2.  Results and evaluation  48

5.1.2.1  Results for urban areas  49

5.1.2.2  Results for open areas  54

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Table of Contents

5.1.2.3  Overall results  57

5.2.  TU Munich extraction algorithm on SAR imagery  59

5.2.1.  Test approach  59

5.2.2.  Results and evaluation  59

5.2.2.1  Results for urban areas  59

5.2.2.2  Results for open areas  63

5.2.2.3  Overall results  65

5.3.  Comparison of TU Munich and Intermap extraction algorithms on SAR  

  imagery  66

6.  Practical analysis of extraction algorithms on optical imagery  67

6.1.  Intermap extraction algorithm on optical imagery  67

6.1.1.  Test approach  67

6.1.2.  Results and evaluation  68

6.1.2.1  Results for urban areas  69

6.1.2.2  Results for open areas  75

6.1.2.3  Overall results  78

6.2.  Comparison of results from SAR and optical imagery (Intermap extraction  

  algorithm)  79

6.3.  TU Munich extraction algorithm on optical imagery  80

6.3.1.  Test approach  80

6.3.2.  Results and evaluation  81

6.3.2.1  Results for urban areas  81

6.3.2.2  Results for open areas  83

6.3.2.3  Overall results  85

6.4.  Comparison of results from SAR and optical imagery (TU Munich  

  extraction algorithm)  86

6.5.  Comparison of TU Munich and Intermap extraction algorithms on optical  

  imagery  87

6.6.  Enhanced extraction by merging of SAR and optical imagery results  87

6.6.1.  Test approach  88

6.6.2.  Results and evaluation  89

7.  Summary and outlook  96

7.1.  Summary  96

7.2.  Outlook  97

  References  99

  List of Figures  103

  List of Tables  105

Appendix   106

  A 1 Alterable parameters for Intermap extraction algorithm (SAR imagery and  

  urban areas)  106

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Table of Contents

  A 2 Alterable parameters for Intermap extraction algorithm (SAR imagery and  

  open areas)  107

  A 3 Alterable parameters for Intermap extraction algorithm (optical imagery  

  and urban areas)  108

  A 4 Alterable parameters for Intermap extraction algorithm (optical imagery  

  and open areas)  109

  B 1 Alterable parameters for TU Munich extraction algorithm (SAR imagery  

  and urban areas)  110

  B 2 Alterable parameters for TU Munich extraction algorithm (SAR imagery  

  and open areas)  111

  B 3 Alterable parameters for TU Munich extraction algorithm (optical imagery  

  and urban areas)  112

  B 4 Alterable parameters for TU Munich extraction algorithm (optical imagery  

  and open areas)  113

7

1. Introduction

8

1. Introduction

9

1. Introduction

10

2. Radar systems

11

2. Radar systems

12

2. Radar systems

13

2. Radar systems

14

2. Radar systems

15

2. Radar systems

16

2. Radar systems

17

2. Radar systems

18

2. Radar systems

19

2. Radar systems

20

3. Extraction of linear objects from SAR and optical imagery

21

3. Extraction of linear objects from SAR and optical imagery

22

3. Extraction of linear objects from SAR and optical imagery

23