2007 ieee international symposium on electromagnetic compatibility
2007 ieee international symposium on electromagnetic compatibility
2007 ieee international symposium on electromagnetic compatibility
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30EMC <str<strong>on</strong>g>2007</str<strong>on</strong>g> ADVANCE PROGRAMWaveform diversity in multistatic radar systems can enhance distributedradar system performance. Dynamically changing the <strong>electromagnetic</strong>emanati<strong>on</strong>s of radar and communicati<strong>on</strong>s systems, however,poses an <strong>electromagnetic</strong> <strong>compatibility</strong> (EMC) challenge. Dataare provided illustrating how waveform diversity improves multistaticradar system performance. An approach for maintaining EMC ina dynamically changing envir<strong>on</strong>ment is also provided.Detecti<strong>on</strong>/Imaging of Buried Objects: Using Spatial/AngularDiversity with Distributed/Embedded Sub-Surface Sensorsfor Reduced Mutual Coupling and Suppressed EMEmissi<strong>on</strong>sJohn Norgard, U. S. Air Force Research Lab/SNRT; Kevin Magde, U. S.Air Force Research Lab/Sensors Directorate; Michael Wicks, U. S. Air ForceResearch Lab/Sensors Directorate; Andrew Drozd, ANDRO Computati<strong>on</strong>alSoluti<strong>on</strong>s, LLC; and Randall Musselman, U. S. Air Force AcademyThe proliferati<strong>on</strong> of strategic subsurface sanctuaries has increased theneed for enhanced remote sensing techniques providing for the accuratedetecti<strong>on</strong> and identificati<strong>on</strong> of deeply buried objects. A new RFTomographic Technique is proposed in this c<strong>on</strong>cept paper for developingRF CAT Scans of buried objects using spectral, spatial/angular,and polarizati<strong>on</strong> diversity. This imaging technique uses an embeddedring of subsurface radiators, delivered by earth-penetrating, n<strong>on</strong>explosive,electr<strong>on</strong>ic “e-bombs”, as the source of str<strong>on</strong>g undergroundradiated transmissi<strong>on</strong>s and uses distributed surface-c<strong>on</strong>tact sensors tocollect the tomographic data for relay to a circling UAV and transmissi<strong>on</strong>to a remote c<strong>on</strong>trol site (using layered sensing). Threedimensi<strong>on</strong>alimaging algorithms are being developed to detect,image, and characterize deeply buried targets. Distributed transmittersand receivers significantly increase unwanted mutual couplingand EM emissi<strong>on</strong>s that interfere with signal recepti<strong>on</strong>. However, byembedding the transmitters underground, reduced mutual couplingand EM emissi<strong>on</strong>s (and improved signal-to-noise ratios) can beachieved. Simple surface SAR experiments over deep mine shaftshave been performed to validate the 3D processing algorithms using2D surface SAR sensor data. WIPL-D models have also been used tosimulate the embedded and distributed sensors and to verify the significantenhancement in the received signal-to-noise ratio obtainedby burying the radiating ring under the surface sensors.Electromagentic Diversity and EMI Implicati<strong>on</strong>s for MultipleCo-Sited Radars and Targeting Applicati<strong>on</strong>sAndrew Drozd, ANDRO Computati<strong>on</strong>al Soluti<strong>on</strong>s, LLC; IrinaKasperovich, ANDRO Computati<strong>on</strong>al Soluti<strong>on</strong>s, LLC; Ruixin Niu,Syracuse University; and Pramod Varshney, Syracuse UniversityReal-time fusi<strong>on</strong> of data collected from a variety of co-located radarsthat acquire informati<strong>on</strong> in a cooperative manner from multiple perspectivesand/or different frequencies, is being shown to provide amore accurate and effective way of tracking complex targets in amulti-target scenario. This is more advantageous than employing asingle radar or a group of radars operating independently. This paperdescribes a cooperative multi-sensor approach in which multipleradars operate together in a n<strong>on</strong>-interference limited manner. Athree-fold approach is presented: (i) applying multiobjective jointoptimizati<strong>on</strong> algorithms to set limits <strong>on</strong> the operati<strong>on</strong>al parametersof the radars to preclude <strong>electromagnetic</strong> interference; (ii) measuringand processing radar returns in a shared manner for target featureextracti<strong>on</strong> based <strong>on</strong> <strong>electromagnetic</strong> diversity principles in c<strong>on</strong>juncti<strong>on</strong>with target scattering cross secti<strong>on</strong>s; and (iii) employing featureaidedtrack/fusi<strong>on</strong> algorithms to detect, discriminate, and follow realtargets from clutter noise. The results of computer simulati<strong>on</strong>s areprovided that dem<strong>on</strong>strate the advantages of this approach.The True Meaning of Electromagnetic Diversity SeenThrough the First Principles of Fundamental PhysicsTapan K. Sarkar, Department of Electrical Engineering and ComputerScience, Syracuse UniversityThe word Diversity in the dicti<strong>on</strong>ary implies variety in form. Andthe basic c<strong>on</strong>cept derived from these principles is that if <strong>on</strong>e has multiplecopies of the same system, presumably <strong>on</strong>e would have a betterchance of achieving the desired goals. The fundamental problemwith this simplistic way of reas<strong>on</strong>ing is that <strong>on</strong>e needs to understandthe physical envir<strong>on</strong>ment where such an experiment needs to be carriedout and how <strong>on</strong>e should interpret the final result. The currentstate of the art applies some statistical framework to the physicalscene to explain the added advantage of diversity. To appreciate thetrue physical significance of diversity we have to go back to the roots!We need to understand first, what the statistical framework impliesand sec<strong>on</strong>dly, how it relates to the problem at hand.Distributed and Layered Sensing: Relevant EMC IssuesMichael Wicks; and William Moore, — U. S. Air Force ResearchLab/Sensors DirectorateOne can easily envisi<strong>on</strong> future military operati<strong>on</strong>s and emergingcivilian requirements (e.g. intelligent unmanned vehicles for urbanwarfare, and intelligent manufacturing plants) that will be both complexand stressing and will demand innovative sensors and sensorc<strong>on</strong>figurati<strong>on</strong>s. The goal of our research into Distributed and LayeredSensing is to develop a cost effective and extendable approach for providingsurveillance for a variety of applicati<strong>on</strong>s in dynamically changingmilitary and civilian envir<strong>on</strong>ments. Within Distributed andLayered sensing, we foresee a new sensor archetype. In this paradigm,sensors and algorithms will be aut<strong>on</strong>omously altered depending <strong>on</strong>the envir<strong>on</strong>ment. Radars will use the same returns to perform detecti<strong>on</strong>and discriminati<strong>on</strong>, to adjust the platform flight path, andchange missi<strong>on</strong> priorities. The sensors will dynamically and automaticallychange waveform parameters to accomplish these goals.Disparate sensors will communicate and share data and instructi<strong>on</strong>sin real-time. Intelligent sensor systems will operate within andbetween sensor platforms such that the integrati<strong>on</strong> of multiple sensordata provides informati<strong>on</strong> needed to achieve dynamic goals andavoid <strong>electromagnetic</strong> fratricide. Intelligent sensor platforms workingin partnership will increase informati<strong>on</strong> flow, minimize ambiguities,and dynamically change multiple sensors’ operati<strong>on</strong>s basedup<strong>on</strong> a changing envir<strong>on</strong>ment. C<strong>on</strong>comitant with the current emphasis<strong>on</strong> more flexible defense structures, Distributed and Layered sensingwill allow the appropriate incremental applicati<strong>on</strong> of remotesensing assets by matching resources to the situati<strong>on</strong> at hand.Effect of In-Band Intermodulati<strong>on</strong> Interference <strong>on</strong> Direct-Sequence Spread Spectrum (DSSS) Communicati<strong>on</strong>Systems for Electromagnetically Diverse Applicati<strong>on</strong>sIlteris Demirkiran, Embry-Riddle Aer<strong>on</strong>autical University; D<strong>on</strong>ald Weiner,Syracuse University; and Andrew Drozd, ANDRO Computati<strong>on</strong>alSoluti<strong>on</strong>s, LLCThe goal of this paper is to analyze the effect of n<strong>on</strong>linearities <strong>on</strong> theperformance of direct-sequence spread spectrum systems in the c<strong>on</strong>textof <strong>electromagnetic</strong>ally diverse applicati<strong>on</strong>s. Inter-modulati<strong>on</strong>products due to n<strong>on</strong>linear amplificati<strong>on</strong> are analyzed and the effect ofn<strong>on</strong>linearities is illustrated by means of a computer simulati<strong>on</strong> result.For the performance measure, bit-error rate (BER) is c<strong>on</strong>sidered toassess the effect of in-band intermodulati<strong>on</strong> interference. The findingsof this study will be of benefit to the waveform diversity community.This community is c<strong>on</strong>cerned with assessing the effects of©<str<strong>on</strong>g>2007</str<strong>on</strong>g> IEEE www.emc<str<strong>on</strong>g>2007</str<strong>on</strong>g>.org