Application of coupled-wave Wentzel-Kramers-Brillouin approximation to ground penetrating radar

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 of interest for ground penetrating radar (GPR) applications. For the analytical description of the signal generated by the interaction of the emitted pulse with the environment, we developed and implemented a novel time-domain version of the coupled-wave Wentzel-Kramers-Brillouin approximation. We compared our solution with finite-difference time-domain (FDTD) results, achieving a very good agreement. We then applied the proposed technique to two case studies: in particular, our method was employed for the post-processing of experimental radargrams collected on Lake Chebarkul, in Russia, and for the simulation of GPR probing of the Moon surface, to detect smooth gradients of the dielectric permittivity in lunar regolith. The main conclusions resulting from our study are that our semi-analytical method is accurate, radically accelerates calculations compared to simpler mathematical formulations with a mostly numerical nature (such as the FDTD technique), and can be effectively used to aid the interpretation of GPR data. The method is capable to correctly predict the protracted return signals originated by smooth transition layers of the subsurface dielectric medium. The accuracy and numerical efficiency of our computational approach make promising its further development

100/1000 Gbit/s Ethernet and beyond, Journal of Telecommunications and Information Technology, 2009, nr 1

100 Gbit/s Ethernet is foreseen in metro and access by 2014, while 1 Tbit/s Ethernet is forecasted for trunklinks before 1020. This paper reviews the advantages and constraints of the optical networking and discusses how they meet the 100 Gbit/s Ethernet needs

The present and future of nonlinear optics applications in photonic telecommunication networks, Journal of Telecommunications and Information Technology, 2000, nr 1-2

A state-of-the art of photonic telecommunication technology is reviewed and possible directions of future developments are outlined. In particular, the impact of nonlinear optical phenomena inherent to silica glass on the transmission performance of wavelength-division multiplexed optical signal through fibres is discussed. Also potential applications of nonlinear photonic devices for the purposes of optical signal processing that is foreseen in future all-optical networks are pointed out

Towards broadband global optical and wireless networking, Journal of Telecommunications and Information Technology, 2004, nr 3

This paper presents a novel, non-conventional approach to the future optical and wireless hybrid transport network, capable of supporting/dominant kinds of traffic, i.e., voice/real time, wireless and packet data traffic in a single transport network. The proposed model combines different technologies as connection and connectionless networks, optical cable and wireless (microwave/millimetre wave or optical wireless), being suitable for a variety of purposes and services in order to achieve global broadband networking features. Our new networking model contains an extension to wireless world in order to achieve mobility and personalisation of connection. From the networking point of view it consists of an upgrade of real-time traffic with the microwave modulated optical wave, in order to carry out conventional mobile wireless signals via optical fibres over long distances and without significant distortion. The whole available bandwidth can be fully exploited in the hybrid network. In the IP part of the network the quality of service (QoS) can be differentiated for various classes of packets and network reliability/survivability can be categorised for the whole hybrid network. This proposal combines complete and revolutionary shift to packet traffic with mooth evolutionary upgrades. We believe the model presented here is a powerful tool to trace the future evolution of telecommunications worldwide for the next 25 years

Overview and comparative study of GPR international standards and guidelines – COST Action TU1208

Ground Penetrating Radar (GPR) can be effectively used for non-destructive testing of composite structures and diagnostics affecting the whole life-cycle of civil engineering works. Nevertheless, few recognised international standards exist in this field and inhomogeneous recommendations are present in different countries. Moreover, the levels of knowledge, awareness and experience regarding the use of GPR in civil engineering vary strongly across different European areas. The COST Action TU1208 is working hard on leveraging these differences, by sharing and disseminating knowledge and experience, as well as by developing guidelines and protocols for a safe and effective use of GPR in civil engineering. GPR users need to know which is the best way to conduct GPR measurements and what the quality level for the results should be. The TU1208 guidelines will ensure a higher efficiency and quality of GPR services and they will constitute a scientific basis for the introduction of European Standards on the application of GPR in civil engineering. The aim of this contribution is to present an in-depth overview and critical analysis of the existing GPR international and national standards and guidelines. The main documents considered in our work are listed and briefly described in the following. Three standards are provided by the American Society for Testing and Materials (ASTM), to guide the GPR use for subsurface investigation, evaluation of asphalt-covered concrete bridge decks, and determination of pavement-layer thickness: 1. ASTM D6432-11, Standard Guide for Using the Surface Ground Penetrating Radar Method for Subsurface Investigation, ASTM International, West Conshohocken, PA, 2011, www.astm.org, DOI: 10.1520/D6432-11. 2. ASTM D6087-08, Standard Test Method for Evaluating Asphalt-Covered Concrete Bridge Decks Using Ground Penetrating Radar, ASTM International, West Conshohocken, PA, 2008, www.astm.org, DOI: 10.1520/D6087-08. 3. ASTM D4748-10, Standard Test Method for Determining the Thickness of Bound Pavement Layers Using Short-Pulse Radar, ASTM International, West Conshohocken, PA, 2010, www.astm.org, DOI: 10.1520/D4748-10. Further ASTM standards exist, not focused on GPR but including useful information (details are not provided here, for brevity reasons). There are no standards in Europe, instead, guiding the GPR use for subsurface prospecting and regulating the numerous applications of this non-destructive technique. The following Radio and Telecommunications Terminal Equipment (RTTE) directive applies to GPR equipment and allows the placing of a GPR product on the European (EU) market for sale: Directive 1999/5/EC of the European Parliament and of the Council of 9 March 1999, on radio equipment and telecommunications terminal equipment and the mutual recognition of their conformity. Official Journal of the European Union, L 91, 7.4.1999, open access on ec.europa.eu. This document will be repealed, since 13 June 2016, by the following RTTE directive: Directive 2014/53/EU of the European Parliament and of the Council of 16 April 2014, on the harmonisation of the laws of the Member States relating to the making available on the market of radio equipment, repealing Directive 1999/5/EC. Official Journal of the European Union, L 153, 22.5.2014, open access on ec.europa. Although conformance to the RTTE directive allows the placing of a GPR product on the market for sale, it does not give authority for its use. In order to use the equipment, in the majority of EU member countries, a license is required. The license is controlled and issued by the radio administration in each of the member countries. The Electronic Communications Committee (ECC) of the European Conference of Postal and Telecommunications Administrations (CEPT) considers and develops policies on electronic communications activities in European context, taking account of European and international legislations and regulations. There are 48 European countries involved in the CEPT, which cooperate to regulate posts, radio spectrum and communications networks in Europe. The ECC agreed to the decision ECC/DEC/(06)08, specifically referred to GPR and Wall Penetrating Radar (WPR) systems: ECC Decision of 1 December 2006 on the conditions for use of the radio spectrum by Ground- and Wall- Probing Radar (GPR/WPR) imaging systems, 14 December 2006, open access on www.cept.org. This is not legally binding on member countries. It is currently implemented by 25 and partly implemented by 2 of the 48 administrations; 5 further administration are considering and studying the decision. Outside Europe, different approaches exist, ranging from very formal technical approval and licensing conditions to no specific rules. A series of standards and codes, introduced by the European Telecommunications Standards Institute (ETSI), regulate the GPR use and its emissions of electromagnetic radiation in Europe: 1. ETSI EN 301 489-1 v1.9.2, Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 1: Common technical requirements, Sept. 2011, open access on www.etsi.org, Ref. DEN/ERM-EMC-230-32, 45 pp. [7]. This document is a Harmonized European Standard. 2. ETSI EN 301 489-32 v1.1.1, Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 32: Specific conditions for Ground and Wall Probing Radar applications, Sept. 2009, open access on www.etsi.org, Ref. DEN/ERM-EMC-230-32, 12 pp. [8]. This document is currently (May 2015) a Candidate Harmonized European Standard (Telecommunication Series). 3. ETSI EN 302/066-1 v1.2.1, Electromagnetic compatibility and Radio spectrum Matters (ERM); Ground- and Wall- Probing Radar applications (GPR/WPR) imaging systems; Part 1: Technical characteristics and test methods, Dec. 2007, open access on www.etsi.org, Ref. REN/ERM-TG31A-0113-1, 25 pp. [9]. This document is a Harmonized European Standard (Telecommunications series). 4. ETSI EN 302/066-2 v1.2.1, Electromagnetic compatibility and Radio spectrum Matters (ERM); Ground- and Wall- Probing Radar applications (GPR/WPR) imaging systems; Part 2: Harmonized EN covering essential requirements of article 3.2 of the RTTE Directive, Dec. 2007, open access on www.etsi.org, Ref. REN/ERM-TG31A- 0113-2, 12 pp. [10]. This document is a Harmonized European Standard (Telecommunications series). 5. ETSI EG 202 730 v1.1.1, Electromagnetic compatibility and Radio spectrum Matters (ERM); Code of Practice in respect of the control, use and application of Ground Probing Radar (GPR) and Wall Probing Radar (WPR) systems and equipment, Sept. 2009, open access on www.etsi.org, Ref. DEG/ERM-TGUWB-010, 11 pp. [11]. This document is currently (May 2015) an ETSI guide. Few National GPR Guidelines and Standards exist in Europe. In France, the National standard NF S 70-003, Parts 1-3, is concerned with the use of GPR to detect buried utilities. Still in France, Cerema/Ifsttar produced protocols for road inspection. In Germany, the DGZfP e.V. (German Society for Non-Destructive Testing) published a fact sheet called “Merkblatt B10” on the radar method for non-destructive testing in civil engineering (2008). Still in Germany, there is a BASt (Federal Highway Administration) instruction sheet on the use of GPR to gain inventory data of road structure (2003). In Poland, the national regulation of September 24, 1998 (Dz.U. Nr 126 poz. 839) cites ‘georadar testing’ as a method to investigate the soil structure. In Scandinavia, recommendations for guidelines were developed during the MARA NORD Project (2010-2012) on the use of GPR in asphalt air voids content measurements, in road construction quality control, in bridge deck surveys, in road rehabilitation projects and in site investigations. Acknowledgement This work stems from the research activities of COST (European COoperation in Science and Technology) Action TU1208 “Civil engineering applications of Ground Penetrating Radar.” The Authors thank COST (www.cost.eu) for funding the Action TU1208 (www.GPRadar.eu). Part of this work was carried out during the Short-Term Scientific Mission STSM-TU1208-24656 “Comparative study of GPR international standards and guidelines” (Dr Lara Pajewski, Italy, visiting Prof Marian Marciniak, Poland)

Impact of nonlinear optical phenomena on dense wavelength division multiplexed transmission in fibre telecommunication systems, Journal of Telecommunications and Information Technology, 2000, nr 1,2

In the paper results of analysis of nonlinear phenomena in optical fibres: Self-Phase Modulation, Cross-Phase Modulation, Four-Wave Mixing and Stimulated Raman Scattering and their influence on Dense-Wavelength Division Multiplexed system performance are reported. Different nonuniform optical channel allocation schemes based on ITU Recommendation G.692 100 GHz frequency grid are compared with uniform channel distribution. The level of nonlinear cross-talk is determined for different levels of the total optical power. As an example a 10 Gbit/s D-WDM dispersion-shifted single mode fibre link with dispersion-compensating fibres is envisaged. The directions for optimization of the system design in view of actual international standardization trends are pointed out

IP over optical network: strategy of deployment, Journal of Telecommunications and Information Technology, 2001, nr 2

In this paper, we present main issues of application IP technology directly over optical transport network. The capabilities ofWDM transmission systems and techniques which allow the integration of IP with the physical layer are discussed. A detailed description of most solutions is reported. In particular the MPLS/MPl S techniques are discussed in detail. Also problems for further development are outlined

Non-linear optimization for multi-path source routing in OBS networks

Optical Burst Switching (OBS) architectures without buffering capabilities are sensitive to burst losses. A proper routing strategy may help to reduce such congestion. In this letter we present a novel approach for OBS multi-path source routing problem. Our solution is based on non-linear optimization with a straightforward calculation of partial derivatives. Simulation results demonstrate that optimized routing effectively reduces the overall burst loss probability with respect to shortest path and deflection routing.Postprint (published version

New method of numerical modelling of optical field transformation by inhomogeneous semiconductor layer with time-varying parameters, Journal of Telecommunications and Information Technology, 2000,nr 1,2

A time-domain model of a semiconductor layer with time-dependent inhomogeneous permittivity or conductivity is investigated by solving direct and inverse problems using a novel method, revealing a possibility of wavelength shifting and other desirable optical field transformation, as well as a remote diagnostics of fast time-varying inhomogeneous structures

Optical pulse splitting under temporal variations of reflecting medium, Journal of Telecommunications and Information Technology, 2000, nr 1,2

A possibility of light pulse transformation by transient reflecting medium is investigated theoretically. After solving 1D problem of such a reflection one estimates such a transformation in a plane optical waveguide with time-dependent conductivity of one of the reflected media. Three types of the conductivity time-dependences are considered: harmonic, Bessel-like and splash-like ones. Obtained results show a possibility of pulse splitting under an influence of time-harmonic conductivity and pulse collapse vy the other considered nonstationarities