In the GPR frequency range, electromagnetic wave attenuation is largely controlled by dielectric relaxation processes. A primary relaxation commonly occurs in the 10 – 100 MHz range for many earth materials in which the GPR signal propagates effectively. This relaxation leads to strong nonlinearity in the frequency dependent attenuation and occurs in a frequency range that is often used for gro...

Cytokinesis and spindle positioning require the cortical force regulator G Protein Regulator 1/2 (GPR-1/2). GPR-1/2 is thought to localize to sites of cortical force generation. Does GPR-1/2 also act as a sensor for mechanical stimulation? I mechanically stimulated the cortex by indenting it with a glass needle and observed the cortical localization of a YFP::GPR-1 transgene. I found that corti...

The shape and feature extraction in Ground Penetrating Radar (GPR) data is the most addressed application in present underground object identification technique. The problem of automatically detecting the shape and feature in GPR data is in analysing and fitting the hyperbola features from GPR data objects. To address these, we propose a hyperbole fitting method to extract the shape and feature...

Ground penetrating radar (GPR) has emerged as an effective tool for estimating active layer thickness (ALT) and volumetric water content (VWC) within the active layer. In August 2013, we conducted a series of GPR and probing surveys using a 500 MHz antenna and metallic probe around Barrow, Alaska. We collected about 15 km of GPR data and 1.5 km of probing data. Here, we describe the GPR data pr...

This paper deals with bistatic subsurface probing of a horizontally layered dielectric half-space by means of ultra-wideband electromagnetic waves. In particular, the main objective of this work is to present a new method for the solution of the two-dimensional back-scattering problem arising when a pulsed electromagnetic signal impinges on a non-uniform dielectric half-space; this scenario is ...

Full waveform inversion (FWI) of seismic or Ground Penetrating Radar data provides high-resolution quantitative images of the constitutive parameters of the rock/soil which control seismic/GPR wave propagation. We developed a 2D inversion tool in the frequency domain adapted to the multi-parameter physics controlling GPR propagation in isotropic non dispersive media, i.e. dielectric permittivit...

A method for detecting shallowly buried landmines using sequential GPR data is presented. After removing dominant coherent component of ground surface reflection from GPR data, three kinds of target features related to wave correlation, energy ratio, and signal arrival times are extracted. Since the detection problem treated here is reduced to a binary hypothesis test, an approach based on a li...

It is necessary to detect the target reflections in ground penetrating radar (GPR) images, so that surface metal targets can be identified successfully. In order to accurately locate buried metal objects, a novel method called the Multiresolution Monogenic Signal Analysis (MMSA) system is applied in ground penetrating radar (GPR) images. This process includes four steps. First the image is deco...

In this paper we consider the development of algorithms for the automatic detection of buried threats using ground penetrating radar (GPR) measurements. GPR is one of the most studied and successful modalities for automatic buried threat detection (BTD), and a large variety of BTD algorithms have been proposed for it. Despite this, large-scale comparisons of GPR-based BTD algorithms are rare in...

Thymus-expressed chemokine (TECK) has been reported to chemoattract dendritic cells, thymocytes, and activated macrophages. Here, we show that TECK is a specific agonist for a human orphan receptor called GPR-9-6. We have determined the cDNA sequence of human GPR-9-6 and cloned the corresponding murine cDNA. Human and murine GPR-9-6 expression is very high in the thymus and low in lymph nodes a...