Multi-frequency synthetic-aperture imaging with a lightweight ground penetrating radar system

Forensic Application of FM-CW and Pulse Radar

“…The image becomes an overlay of 128 holographic images, each for every coherent frequency step. Koppenjan et al (2000) stated when using this method, diffraction is fully compensated in both range and cross-range directions; thereby, improving overall image quality.…”

A High-Speed Continuous Wave GPR

“…State-of-the-art CW radar systems usually synthesize the waveform using a phase loop locked oscillator (PLL) [7] or alternatively a direct digital synthesizer (DDS) [8]. The PLL is able to combine the high spectral purity of each synthesized frequency with the capability of scanning a very large bandwidth.…”

“…In this way the band of the DDS is multiplied by a suitable factor in order to match the band of the Voltage Controlled Oscillator (VCO) in the loop, but the hopping time is constrained by the lock time of the PLL, so the DDS speed can not be exploited. The second solution [8] calls for the employment of an analog frequency multiplier to enlarge the DDS bandwidth [7]. Unfortunately this solution is not usable for large bandwidths.…”

Optimization and integration of high‐performance ground penetrating imaging radar system: A research prototype

“…INTRODUCTION Ground penetrating radar (GPR) has been playing an increasingly important role in many applications in nondestructive evaluation (NDE) and subsurface profiling. Common applications include locating and identifying utility supply lines, monitoring environmental sites, assisting archaeological and forensic investigation, surveying surface transportation infrastructure, and detecting structural voids, cavities, and deterioration (Mast et al, 1990;1994;Koppenjan and Bashforth, 1993;Warhus, 1993;Lockwood and Lee, 1997;Koppenjan et al, 2000). At UC Santa Barbara, significant research has been conducted over the past 15 years to advance the tomographic imaging capability of the GPR systems.…”