Through-Wall Imaging With UWB Radar System - KEMT FEI TUKE

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4.1 Through-Wall TOA Estimation 50 Table 4.3: Error in TOA estimation for through-wall scenario. Method Straight line between Simple wall Proposed antenna and target compensation method T OA[ns] 11.188 14.238 14.994 ErrT OA[%] 25.383 5.042 0.000 and frequency, as it is shown in equation (4.2.2). However, these parameters cause neglectable modification of the propagation velocity in praxis. 4.1.5 Irregular Movement Compensation The antenna system, or the whole radar system has to move in scanning direction during SAR scanning. A very precise and linear scanning system can be used in a laboratory environment. However, it is impractical in real measurement scenarios. In scanning direction (X - axis): For rescue or security applications a moving trolley or vehicle is used. In this case it is almost impossible to move it with a constant velocity. Most of the migrations require input dataset (B-scan) with linear distances between two subsequent scans. Otherwise the output image will be deformed. We used hand moving trolley with positioner system for measurements pictured in Fig. 4.1.5. The information about actual position in scanning direction is continuously saved with every received impulse response from the radar device. In order to align all scans to the regular grid, where every two subsequent scans have the same distances, a vector of antenna positions s in scanning direction shown in Fig. 4.1.6 b) is created. The antenna positions in vector s are linearly dependent on the number of scans. The calibrated and preprocessed B-scan BP n (X, k) is interpolated through Spline interpolation Spline as: BP C (X, k) = Spline (BP (X, k) , s) (4.1.14) where BP C (X, k) is a B-scan with compensated irregular trolley movement in the scanning direction. For the next processing, the BP C (X, k) in combination with antennas positions s is used. In looking direction (Z - axis): The irregular movement of scanning trolley leads to a varying distance between antenna system and scanning objects. In order to compensate this behavior during migration, the precise distance between antenna and the wall Wdi has to be known.
4.1 Through-Wall TOA Estimation 51 Fig. 4.1.5: Trolley antenna movement - positioner system. Position in X direction [m] Position in X direction [m] 2.5 2 1.5 1 0.5 0 2 1.5 1 0.5 0 a) Measured antennas positions 20 40 60 80 100 120 140 160 180 200 b) Vector s of antennas positions Number of scans 20 40 60 80 100 120 140 160 180 200 Number of scans Fig. 4.1.6: Antenna system positions in X direction. a) Measured. b) Vector s. The front wall that is directly in front of the antennas is clearly visible in the measured data set. It mostly represents the most significant part of the energy in B-scan after crosstalk removal. The positions of peak in dataset caused by the wall reflections could be effectively used to estimate the distances between the antennas and the wall Wdi. The B-scan of through-wall scanning with zoom of the front
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TECHNICAL UNIVERSITY OF KOˇSICE Fa
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Acknowledgement I give a sincere gr
Page 5 and 6:
CONTENTS v 3 Goals of Dissertation
Page 7 and 8:
LIST OF FIGURES vii List of Figures
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LIST OF FIGURES ix 4.4.3 Aquarium f
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LIST OF FIGURES xi List of Symbols
Page 13 and 14: LIST OF FIGURES xiii kx - Horizonta
Page 15 and 16: Chapter 1 Introduction 1.1 Motivati
Page 17 and 18: 1.3 Thesis Organization 3 In additi
Page 19 and 20: Chapter 2 State Of The Art 2.1 UWB
Page 21 and 22: 2.2 Through-Wall Radar Basic Model
Page 23 and 24: 2.3 SAR Scanning 9 and shall remain
Page 25 and 26: 2.4 Calibration and Preprocessing 1
Page 27 and 28: 2.4 Calibration and Preprocessing 1
Page 29 and 30: 2.5 Radar Imaging Methods Overview
Page 55 and 56: Chapter 4 Selected Research Methods
Page 57 and 58: 4.1 Through-Wall TOA Estimation 43
Page 63: 4.1 Through-Wall TOA Estimation 49
Page 71 and 72: 4.2 Measurements of the Wall Parame
Page 81 and 82: 4.3 Highlighting of a Building Cont
Page 91 and 92: 4.4 Measurements of the Practical S
Page 99 and 100: 5.1 Conclusion and Future Work 85 5
Page 101 and 102: 50 100 150 200 250 300 350 400 Z 45
Page 103 and 104: 50 100 150 200 250 300 350 400 Z 45
Page 105 and 106: 50 100 150 200 250 300 350 400 Z 45
Page 107 and 108: 50 100 150 200 250 300 350 400 Z 45
Page 109 and 110: Z [cm] Z [cm] 50 100 150 200 250 30
Page 111 and 112: Z [cm] 50 100 150 200 250 300 b) Em
Page 113 and 114: BIBLIOGRAPHY 99 [13] T. W. Barrett,
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BIBLIOGRAPHY 101 [46] G. Derveaux,
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BIBLIOGRAPHY 103 [81] S. Kidera, T.
Page 119 and 120:
BIBLIOGRAPHY 105 [115] J. Sachs, M.
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BIBLIOGRAPHY 107 [150] O. Yilmaz, S
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Through-Wall Imaging With UWB Radar System - KEMT FEI TUKE

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