Stepped-frequency radar signal processing

Abstract Stepped-frequency radar is a prominent example of the class of continuous-wave radar systems. Since raw data are recorded in frequency-domain direct investigations referring to the frequency content can be done on the raw data. However, a transformation of these data is required in order to obtain a time-domain representation of the targets illuminated by the radar. In this paper we present different ways of arranging the raw data which then are processed by means of the inverse fast Fourier transform. On the basis of the time-domain result we discuss strengths and weaknesses of each of these data structures. Furthermore, we investigate the influence of phase noise on the time-domain signal by means of an appropriate model implemented in our simulation tool. We also demonstrate the effects of commonly known techniques of digital signal processing, such as windowing and zero-padding of frequency-domain data. Finally we present less commonly known methods, such as the processing gain of the (inverse) fast Fourier transform by means of which the signal to noise ratio of the time-domain signal can be increased.

[1]  P. van Genderen.  The effect of phase noise in a stepped frequency continuous wave ground penetrating radar , 2001 .

[2]  H. E. Rowe,et al.  Signals and Noise in Communication Systems , 1965 .

[3]  B. Mahafza.  Introduction to radar analysis , 1998 .

[4]  W. M. Carey,et al.  Digital spectral analysis: with applications , 1986 .

[5]  D. Wehner.  High Resolution Radar , 1987 .

[6]  Susan E. Alcock,et al.  A geophysical investigation of a newly discovered Early Bronze Age site near Petra, Jordan , 2014 .

[7]  Richard G. Lyons,et al.  Understanding Digital Signal Processing , 1996 .

[8]  Joerg Schoebel,et al.  Comparison of antenna dispersion and digital signal processing effects in ultrawideband Ground Penetrating Radar systems , 2014 .

[9]  A. M. Abbas,et al.  Discrimination between landmine and mine-like targets using wavelets and spectral analysis , 2013 .

[10]  Joerg Schoebel,et al.  Shielded loaded bowtie antenna incorporating the presence of paving structure for improved GPR pipe detection , 2014 .

[11]  L. Rabiner,et al.  The chirp z-transform algorithm , 1969 .

[12]  V. Kovalenko,et al.  Landmine detection and discrimination based on GPR data , 2004, Proceedings of the Tenth International Conference on Grounds Penetrating Radar, 2004. GPR 2004..

[13]  Joerg Schoebel,et al.  Investigations on the sensitivity of a stepped-frequency radar utilizing a vector network analyzer for Ground Penetrating Radar , 2014 .

[14]  J. Schoebel,et al.  Information extraction from ultrawideband ground penetrating radar data: A machine learning approach , 2012, 2012 The 7th German Microwave Conference.

[15]  Motoyuki Sato,et al.  in situ measurement of pavement thickness and dielectric permittivity by GPR using an antenna array , 2014 .