We proposed efficient techniques for passive detection and localization of emitters of low probability of intercept signals. These are the generalized likelihood ration test (GLRT) detector and the maximum likelihood estimator (MLE). We derived the theoretical bounds for the localization variance, the Cramer-Rao lower bound (CRLB), and showed that the MLE attains the bounds. We further investigated the problems of optimal sensor configuration, knowledge aided geo-location design as well as method to improved the TDOA geo-location technique.

关键词：无线通信；探测器；宽带；发射器；电台频率地理位置

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A biosensor for the detection of organophosphates in water was created by immobilizing acetylcholinesterase (AChE) on a carbon screen printed electrode using peptide nanotubes (PNT) and Nafion(registered trademark). This sensor was used with acetylthiocholine (ASCh) substrate to detect the inhibitory effects of malathion. The stability of the encapsulated enzyme was measured over 50 days of storage at 4 deg C in a phosphate buffer solution. The oxidation of thiocholine, a product of the enzymatic reaction of ASCh and AChE, was used to measure the activity of the encapsulated enzyme. Cyclic voltammograms were taken in an ASCh and phosphate buffer solution, and the peak oxidation was used to measure the performance of the sensor. Amperometric studies were also conducted at 310 mV vs Ag/AgCl to measure the response of the sensors to ASCh and malathion. This research demonstrates that the use of PNTs and Nafion(registered trademark) allows the sensor to remain stable under these conditions for a much longer period than similar biosensors relying on adsorption alone, losing 17.3and 14.2, activity, respectively, after 50 days. Detection limits of as low as 48 nM of malathion were obtained using PNT, and 102 nM using PNT and Nafion(registered trademark).

关键词：传感器；碳纳米管；乙酰胆碱酯酶；生物探测器

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OrthopterNets represent an ongoing R&D program which aims to apply insects as relays for chemical sensor detectors and other types of messages over distances of a few meters to hundreds or thousands of meters. OrthopterNets establish ad hoc communications networks formed by insect nodes to pass information from sensors to one or more detection endpoints. The networks may be formed among calling insects (e.g., as with crickets and katydids) via acoustic modulation of their calls, or through radiofrequency transceivers attached to the insects. This paper summarizes ongoing work towards the development of a viable OrthopterNet implementation.

关键词：通信网络；声波信号；化学剂探测器；微机电系统；昆虫

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Navigation of gun-launched precision munitions using affordable technologies is investigated. Estimation algorithms were developed to blend flight dynamic models with measurements from inertial sensors and, if available, global positioning system (GPS). The launch and flight characteristics of the unique, gun-launched environment were exploited both in the state estimator and for novel heuristic parameter identification. The algorithm included using low- cost inertial sensor arrays and general GPS availability. Experimental results from guided mortar flights indicate that the algorithm with only inertial sensor measurements yields position errors less than 40 m over a 30-s flight. Position errors from the experiments decrease slightly using loose coupling when GPS is available. Simulations were conducted to assess algorithm performance over a wider range of conditions. These results demonstrate that position errors are less than tens of meters for flight times of interest to munitions. Estimation is intolerant to inertial sensor errors due to the novel manner in which known flight dynamics are used to compensate measurements. Overall, this effort shows that navigation error resulting from a low throughput algorithm using affordable inertial sensors is sufficient to increase system accuracy for munitions.

关键词：传感器；探测器；卡尔曼滤波；全球定位系统

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The National Telecommunications and Information Administration (NTIA), in coordination with the Federal Communications Commission (FCC) and federal agencies, has established a Spectrum Sharing Innovation Test-Bed pilot program to examine the feasibility of increased sharing between federal and non-federal users. The pilot program is evaluating the ability of dynamic spectrum access (DSA) devices employing spectrum sensing and/or geo-location technologies to share spectrum with land mobile radio (LMR) systems operating in the 410-420 MHz Federal band and in the 470-512 MHz non-Federal band. Since NTIA published the Test-Bed Phase I test plan on its website in February 2009, it has been engaged in testing DSA devices at its laboratory, the Institute for Telecommunications Sciences (ITS), in Boulder, CO. The Phase I tests assess the performance and behavior of DSA devices in response to simulated LMR environment signals within a laboratory setting. The Phase I test plan document provided a notional definition of subsequent Phase II and III field testing. Phase II will assess the spectrum sensing capabilities of DSA devices in a live LMR environment with sufficient DSA transmitter attenuation to prevent interference to LMR systems. In Phase III, the DSA devices transmitter attenuation will be removed and the devices will be allowed to operate freely in a variety of live LMR radiofrequency signal environments.

关键词：无线通信；频谱；无线电系统；频率分配；频谱感知

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The increased use of Wireless Sensor Networks (WSN) for geolocation has led to an increased reliance on this technology. Jamming, protecting jamming, and detecting jamming in a WSN are areas of study that have greatly increased in interest. This research uses simulations and data collected from hardware experiments to test the effects of jamming on a WSN. Hardware jamming was tested using a Universal Software Radio Peripheral (USRP) Version 2 to assess the effects of jamming on a cooperative network of Java Sun SPOTs. The research combines simulations and data collected from the hardware experiments to see the effects of jamming on cooperative and noncooperative geolocation.

关键词：多传感器；无线电信号；无线电接收器；信号处理；位置查找

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Functionalized graphene-polyvinylidene fluoride (f-G-PVDF) nanocomposite films were synthesized using simple solvent casting technique. The investigation demonstrates the real time strain response of f-G-PVDF nanocomposite on macro scale under tensile loads and the use of this nanocomposite as 10 strain sensor. This is ascribed to the variation in electrical properties of graphene in the polymer upon mechanical deformation at the nanoscale.

关键词：传感器；探测器；应变计；热塑性复合材料；应变计，热塑性复合材料;探测器;电影，石墨烯，纳米技术

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Errors in the estimated constituent concentrations in optically complex waters due solely to sensor noise in a spaceborne hyperspectral sensor can be as high as 80. The goal of this work is to elucidate the effect of signal-to-noise ratio (SNR) on the accuracy of retrieved constituent concentrations. Large variations in the magnitude and spectral shape of the reflectances from coastal waters complicate the impact of SNR on the accuracy of estimation. Due to the low reflectance of water, the actual SNR encountered for a water target is usually quite lower than the prescribed SNR. The low SNR can be a significant source of error in the estimated constituent concentrations. Simulated and measured at-surface reflectances were used in this study. A radiative transfer code, Tafkaa, was used to propagate the at- surface reflectances up and down through the atmosphere. A sensor noise model based on that of the spaceborne hyperspectral sensor HICO was applied to the at- sensor radiances. Concentrations of chlorophyll-a, colored dissolved organic matter, and total suspended solids were estimated using an optimized error minimization approach and a few semi-analytical algorithms. Improving the SNR by reasonably modifying the sensor design can reduce estimation uncertainties by 10or more.

关键词：传感器；探测器；高光谱图像；信噪比；辐射传输

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Distributed sensor networks (DSN) within the DoD are motivated by a need for pervasive and persistent military surveillance, as addressed in Navy DoD guidance documents. Previous studies have sought to characterize DSNs based on various attributes, taxonomies, and design spaces from more of a theoretical perspective. This paper differs from previous studies by focusing on the establishment and use of measurable, orthogonal, design-level, discriminating attributes (discriminators) for classifying DSNs. DoD and non-DoD applications are then characterized in light of these discriminators. Senior Navy/DoD leadership and other decision makers interested in understanding the characterization of DSNs within the DoD, will find this paper valuable.

关键词：无线通信；探测器；网络；分布式传感器

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Time-delayed variables is of potentially critical impact on product quality within the processes of Metallurgical industry,Aviation industry and Chemical industry.It is very important to detect the sensor fault and estimate the values of time-delayed variables immediately as soon as faults occurred.Any fault of the time-delayed variable implies that a detrimental effect on the process will go unnoticed until the next sample become available.During this time,of course,poor quality product continues to be manufactured,a situation which is clearly unacceptable from a cost-effectiveness point of view.For nonlinear process with time-delayed variables,kernel partial least squares is introduced to monitor and estimate the fault of the Tennessee Eastman benchmark.Simulation results demonstrate the effectiveness of the proposed algorithm.

关键词：传感器；故障检测；核偏最小二乘；KPLS

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