Abstract Ballast fouling in railroad substructure is detrimental to railroad track effectiveness and its structural capacity. Ground penetrating radar (GPR) provides a rapid, effective and continuous approach to assess railroad substructure condition. However, unknown ballast dielectric constant and unclear interface between clean and fouled ballast limit the GPR assessment accuracy. In this st...

Ground penetrating radar (GPR) is a non-destructive geophysical method that uses electromagnetic waves to image the subsurface. A typical GPR system has three main components: transmitter and receiver, directly connected to the transmitting and receiving antennas, and a control unit. Electromagnetic pulses are transmitted into the subsurface and the earth response is recorded. The GPR method is...

Ground penetrating radar (GPR) is an efficient method for soil moisture mapping at the field scale, bridging the scale gap between small-scale invasive sensors and large-scale remote sensing instruments. Nevertheless, commonly-used GPR approaches for soil moisture characterization suffer from several limitations and the determination of the uncertainties in GPR soil moisture sensing has been po...

ground penetration radar (gpr) as a nondestructive method for identifying underground objects has been successfully applied to different fields of science such as geotechnical investigations, oil and gas exploration, geology, pipe detection and archeology investigations. metallic and nonmetallic objects can be identified by this method.  the depth of penetration is dictated by the gpr antennas....

Interpreters are routinely required to develop a continuous model of the subsurface through the integration of available data. One of the issues commonly encountered is how best to “fill in” the region between data points, or describe the region at a scale less than the scale of the sampling. We take this opportunity, as part of the Near-Surface Geophysics issue, to describe research currently ...

BACKGROUND/AIM The gamma-glutamyl transpeptidase-to-platelet ratio (GPR) is a novel serum model, which was reported more accurate than aspartate transaminase-to-platelet ratio index (APRI) and fibrosis index based on four factors (FIB-4) for diagnosing significant fibrosis and cirrhosis in HBV mono-infection in West Africa. We aimed to evaluate the diagnostic performance of GPR for liver fibros...

This thesis is concerned with detection logarithms of non-metallic anti-personnel (AP) land mines and the related signal processing using stepped-frequency ground penetrating radar (SF-GPR) technique. Modern land mines are essentially made out of plastic and ceramic materials. This makes their detection using GPR sensor almost impossible without proper signal processing. Many signal processing ...

OBJECTIVE To compare American-Indian and Caucasian mortality rates from diabetes among tribal Contract Health Service Delivery Areas (CHSDAs) in the Great Plains Region (GPR) and describe the disparities observed. RESEARCH DESIGN AND METHODS Mortality data from the National Center for Vital Statistics and Seer*STAT were used to identify diabetes as the underlying cause of death for each deced...