Theory, Design, Analysis, and Implementation of a Spectrally Agile Frequency-Incrementing Reconfigurable (SAFIRE) Foward-Looking Ground Penetrating Radar
Open Access
- Author:
- Phelan, Brian Richard
- Graduate Program:
- Electrical Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 09, 2016
- Committee Members:
- Ram M. Narayanan, Dissertation Advisor/Co-Advisor
Timothy J. Kane, Committee Chair/Co-Chair
Michael T. Lanagan, Committee Member
Randy K. Young, Committee Member
Michael T. Lanagan, Outside Member - Keywords:
- Stepped-Frequency
Frequency-Incrementing
Forward-Looking
Ground-Penetrating
Radar
GPR
Army Research Laboratory
ARL
Mine Detection
Thinned-Spectrum
Crowded Spectrum
FLGPR
IED
UXO
Synthetic-Aperture Radar
SAR
RF
Radio Frequency
Radio Frequency Interference
RFI
Recursive Sidelobe Mnimization
RSM
SAFIRE
Spectrally Agile Frequency Incrementing Reconfigurable
Signal-to-Clutter Ratio
SCR
Signal-to-Noise Ratio
SNR
Ultra-Wideband
UWB
Yuma
Yuma AZ
YPG - Abstract:
- This thesis discusses the design, implementation, and verification of an ultra-wideband (UWB) stepped-frequency ground-penetrating radar (GPR). The main goal of the Spectrally Agile Frequency-Incrementing REconfigurable (SAFIRE) system was to detect buried and concealed landmines and improvised explosive devices (IEDs) from safe stand-off distances. The radar aims to accomplish this goal in the presence of clutter and radio frequency interference (RFI). This dissertation discusses basic stepped-frequency radar (SFR) principles, SAFIRE system specifications and measurements, theoretical performance of forward-looking GPRs for concealed target detection, experimental SAFIRE radar imagery, radar image formation, and applicable signal processing techniques. Traditional stepped-frequency waveforms consist of multiple pulses of narrowband signals (sinusoids). Unlike impulse-based UWB radars, SFRs have the ability to excise specific frequencies within their operating band, thus reducing interference to nearby systems. Furthermore, through spectral sensing techniques, the frequency bands where RFI is present can easily be removed. A brief synopsis of current state-of-the-art forward-looking GPRs used for concealed target detection is given. The rationale for the principal system specifications and user-controllability is given. System architecture and mixing scheme are discussed with a justification for both. Verification of the system's operational specifications was completed via laboratory measurements and theoretical analysis; the laboratory measurements included transmitted power, spectral purity, receiver gain, receiver noise figure, receiver noise floor, dynamic range, antenna measurements, and overall susceptibility to RFI. Thinned spectrum algorithms are discussed, and their performance on measured experiment data are provided. The dissertation concludes with a summary and discussion of suggested system improvements.