Journal Papers stemming out from Working Group 1  (with acknowledgement to COST Action TU1208)

Project 1.1 – Novel GPR systems            (from the most recent paper to the oldest)

[wg1-p1-j4] V. Ferrara, A. Pietrelli, S. Chicarella, L. Pajewski, “GPR/GPS/IMU system as buried objects locator,” Measurement (Elsevier), 2017, in press, doi: 10.1016/j.measurement.2017.05.014 (Italy)

Abstract: In the last years, Ground Penetrating Radar (GPR) technology has been extensively used in several different fields, including archaeology and cultural-heritage diagnostics. The integration of GPR with other positioning devices, such as a Global Positioning System (GPS) and an Inertial Measurement Unit (IMU), can significantly improve the accuracy of buried-object location, by means of an efficient control of GPR route and attitude. This article aims at investigating solutions for an accurate location of buried objects when a GPR is pulled by a terrestrial vehicle or carried by an aerial platform. In particular, a low-cost system is presented, which integrates functionalities of GPS and IMU specifically dedicated to GPR use. The device has been designed, realized and finally its performance was tested in the laboratory.

[wg1-p1-j3] R. Persico and G. Leucci, “Interference mitigation achieved with a reconfigurable stepped-frequency GPR system,” Remote Sensing, vol. 8(11), Article No. 926, 11 pp., November 2016, doi: 10.3390/rs8110926 (Italy; OPEN ACCESS; STSM OUTCOME)

Abstract: In this contribution, some possible effects of large band electromagnetic interferences on Ground Penetrating Radar (GPR) data are shown, and a possible way to counteract them is shown, too. The mitigation of the interferences is implemented thanks to a prototypal reconfigurable stepped frequency GPR system, that allows to program the integration time of the harmonic tones vs. the frequency. In particular, an algorithm for the measurement of the effects of the interferences in the field (linked to the signal to interference ratio) is proposed and tested vs. experimental data. The paper will show some advantages and some drawbacks of the proposed procedure.

[wg1-p1-j2] R. Persico, D. Dei, F. Parrini, L. Matera, “Mitigation of narrowband interferences by means of a reconfigurable stepped frequency GPR system,” Radio Science, vol. 51(8), pp. 1322–1331, August 2016; doi: 10.1002/2016RS005986 (Italy; INDUSTRY INVOLVEMENT; STSM OUTCOME)

Abstract: This paper proposes a new technique for the mitigation of narrowband interferences by making use of an innovative stepped frequency Ground Penetrating Radar (GPR) system, based on the modulation of the integration time of the harmonic components of the signal. This can allow a good rejection of the interference signal without filtering out part of the band of the useful signal (which would involve a loss of information) and without increasing the power of the transmitted signal (which might saturate the receiver and make illegal the level of transmitted power). The price paid for this is an extension of the time needed in order to perform the measurements. We will show that this necessary drawback can be contained by making use of a prototypal reconfigurable stepped frequency GPR system.

[wg1-p1-j1] E. Huuskonen-Snicker, P. Eskelinen, T. Pellinen, M.-K. Olkkonen, “A New Microwave Asphalt Radar Rover for Thin Surface Civil Engineering Applications,” Frequenz – Journal of RF-Engineering and Telecommunications, vol. 69(7-8), pp. 377-381, January 2015; doi: 10.1515/freq-2015-0034 (Finland; OPEN ACCESS)

Abstract: This paper presents a beyond state-of-the-art, sweeping microwave asphalt radar mounted on a small radio controlled four-wheel-drive rover. The quasi-monostatic, remote-controllable radar operates at Ku-band and has an output power of +10 dBm. Detection follows the zero intermediate frequency principle. The sweep width allows for a depth resolution better than 10 mm. With its four microprocessors and laptop computer processing, the radar system can provide pavement permittivity data with an uncertainty close to 0.1. This is a considerable advancement when applying electromagnetic measurement techniques for applications where near surface or thin surface layer measurements are needed.

Project 1.2 – Design, modelling and optimisation of GPR antennas

[wg1-p2-j1]  C. Warren, A. Giannopoulos, "Experimental and Modeled Performance of a Ground Penetrating Radar Antenna in Lossy Dielectrics,"  IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing (JSTARS), pp. 1-8,  2015; doi: 10.1109/JSTARS.2015.2430933 (United Kingdom; GPR 2014 Special Issue; OPEN ACCESS)

Abstract: The way in which electromagnetic fields are transmitted and received by ground penetrating radar (GPR) antennas is crucial to the performance of GPR systems. Simple antennas have been characterized by analyzing their radiation patterns and directivity. However, there have been limited studies that combine real GPR antennas with realistic environments, which is essential to capture the complex interactions between the antenna and surroundings. We have investigated the radiation characteristics and sensitivity of a GPR antenna in a range of lossy dielectric environments using both physical measurements and a three-dimensional (3-D) finite-difference time-domain (FDTD) model. Experimental data were from measured responses of a target positioned at intervals on the circumference of a circle surrounding the H-plane of the antenna. A series of oil-in-water emulsions as well as tap water were used to simulate homogeneous materials with different permittivities and with complex conductivities. Numerical radiation patterns were created utilizing a detailed 3-D FDTD model of the antenna. Good correlation was shown between the experimental results and modeled data with respect to the strength of the main lobe within the critical angle window. However, there are discrepancies in the strength of main lobe at shallow angles. In all the dielectrics, the main lobes are generally broad due to the near-field observation distance but, as expected, become narrower with increasing permittivity. These results provide confidence for further use of the FDTD antenna model to investigate scenarios such as larger observation distances and heterogeneous environments that are difficult to study experimentally.