Our goal is to develop a portable autonomous ammonium sensor. Such a sensor could be deployed for periods of up to a month aboard ships, moorings or drifting buoys or used as a component in lowered or towed oceanographic instrument packages for vertical profiling. Our technical objective is to develop a robust, relatively simple, inexpensive, low power and compact instrument with a detection limit in the nM range and a sampling frequency of at least 6 samples per hour. Robustness, simplicity, low construction cost, lower power and small size are the practical desiderata for commercial application. Commercialization and the lowered instrument costs that will result are essential to permit wider application throughout the oceanographic community.

关键词：传感器；铵化合物；荧光；光探测器；原位分析；地表水

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The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system
for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower, Inc., and NASA Glenn Research Center. The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot-end and cold-end temperatures, and specified electrical power output for a given heat input. It is difficult to measure heat input to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat input to an ASC. The effort succeeded in designing and fabricating unique sensors, which were integrated into a Stirling convertor ground test and exposed to test temperatures exceeding 700 °C in air for 10,000 hr. Sensor measurements were used to calculate thermal efficiency for ASC–E (Engineering Unit) #1 and #4. The post-disassembly condition of the sensors is also discussed.

关键词：传感器；；放射性同位素热源；热能量；薄膜

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Microelectromechanical systems (MEMS) inertial sensors are commonly used in applications such as inertial navigation and human motion tracking. These inertial sensors provide three-dimensional (3D) orientation, acceleration, rate of turn, and magnetic field information. Manufacturers specify both static and dynamic accuracy for the 3D orientation output of MEMS inertial sensors. The dynamic accuracy is in the form of a root-mean-square (RMS) error and is only valid for certain motions, which are not specified. In this thesis, an investigation of the dynamic accuracy of the Xsens Motion Tracker (MTx) inertial sensor was conducted. The yaw or heading dynamic accuracy of the Microstrain 3DM-GX3-25 inertial sensor also was investigated. A pendulum test apparatus from a previous work was used to test the MTx and GX3. An encoder is installed to the pendulum axis of rotation and provides the reference data needed to calculate the dynamic accuracy of the MTx and GX3. After a series of motion tests, it was concluded that the MTx was within manufacturer specifications for static accuracy but not for dynamic accuracy. More specifically, the heading or yaw accuracy of the MTx and GX3 did not meet manufacturer specifications under the testing motions chosen in this study.

关键词：传感器；精度探测器；惯性导航；微机电系统

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This project supports the capability to perform accurate infrasound sensor calibrations using a piston source and large volume chamber whose output has been independently determined and for which the error budget has been accurately assessed. Since the mid 1980s, Los Alamos National Laboratory (LANL) has operated an infrasound sensor calibration chamber that operates over a frequency range of 0.02 to 4 Hz. This chamber has provided sensitivities, volts/Pa, for sensors used by Los Alamos and others. Under the current program we will restore the chamber function, interrupted by an unexpected move, collaborate with researchers at the Sandia National Laboratory (SNL) Facility for Acceptance, Calibration, and Testing (FACT) Site on sensor issues, calibrate sensors as needed and research new methods for sensor response determination.

关键词：传感器；次声；校准；探测器；活塞

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Differential Global Positioning Systems (DGPS) are susceptible to outages due to blocked or missing satellite signals and/or blocked or missing DGPS correction messages. Outages arise primarily due to environmental reasons: passing under bridges, passing under overhead highway signs, adjacent foliage, etc. Generally, these outages are spatially deterministic, and can be accurately predicted. These outages distract drivers using DGPS-based driver assistive systems, and limit the system robustness. Inertial measurements have been proposed as an augmentation for DGPS. Tests have shown that error rates for even emerging technologies are still too high; a vehicle can maintain lane position for less than three to four seconds. Ring laser gyros can do the job, but $100K per axis is still too expensive for road-going vehicles. To provide robust vehicle positioning in the face of DGPS outages, the IV Lab has developed a technique by which a non-contact, 2D true ground velocity sensor is used to guide the vehicle. Although far from fully developed, the system can maintain vehicle position within a lane for GPS outages of up to 20 seconds. New dual frequency, carrier phase DGPS systems generally require less than 20 seconds to acquire a 'fix' solution after a GPS outage, so the performance of this system should be adequate for augmentation. Proposed herein is basic research which may lead to the development of an inexpensive, 2D, non-contact velocity sensor optimized for vehicle guidance during periods of DGPS outages.

关键词：传感器；全球定位系统；光学探测器；驾驶员辅助系统；驱动程序支持系统；车道引导系统；全球定位系统（DGPS）

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The broad objective of this grant was to develop a generally applicable theory of performance of information-level fusion that provides accurate prediction of post-fusion algorithm accuracy in uncertain environments. determines factors affecting fundamental performance tradeoffs, e.g., sample size, resolution, specificity, and sensitivity of sensors. specifies performance benchmarks allowing quantitative comparison of different fusion algorithms. provides guidelines for algorithm design and optimization. The effort focused on information theoretic fusion methods and our analysis was based on geometric properties of information. Our research has impacted application domains where information theoretic fusion is applied. These included georegistration, remote sensing, multimodality anomaly detection, visualization, and dimensionality reduction.

关键词：传感器；传感器融合；算法；信息论；性能（工程）预测

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The novelly designed optical sensor for autonomous ocean monitoring works on equilibrium principles. When the pH-sensitive reagent solution sitting behind a gas-permeable membrane is exposed to seawater, the CO2 molecules present in the seawater diffuse across the membrane into the reagent and induce a pH change. After equilibrium is reached, the fluorescence is measured and the pCO2 data are recovered from a calibration curve. A specific feature of our measurement technique is the use of excitation ratiometric approach. A violet LED (Light Emitting Diode) and a blue LED are used to excite the sensing reagent through an excitation filter and the pCO2 dependent emission is measured through an emission filter by a photodiode.

关键词：传感器；光学探测器；基地（化学）；二氧化碳；泵；海洋监测；海洋数据采集系统

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Composite materials are increasingly used in modern aircraft for reducing weight, improving fuel efficiency, and enhancing the overall design, performance, and manufacturability of airborne vehicles. Materials such as fiberglass reinforced composites (FRC) and carbon-fiber-reinforced polymers (CFRP) are being used to great advantage in airframes, wings, engine nacelles, turbine blades, fairings, fuselage and empennage structures, control surfaces and coverings. However, the potential damage from the direct and indirect effects of lightning strikes is of increased concern to aircraft designers and operators. When a lightning strike occurs, the points of attachment and detachment on the aircraft surface must be found by visual inspection, and then assessed for damage by maintenance personnel to ensure continued safe flight operations. In this paper, a new method and system for aircraft in-situ damage detection and diagnosis are presented. The method and system are based on open circuit (SansEC) sensor technology developed at NASA Langley Research Center. SansEC (Sans Electric Connection) sensor technology is a new technical framework for designing, powering, and interrogating sensors to detect damage in composite materials. Damage in composite material is generally associated with a localized change in material permittivity and/or conductivity. These changes are sensed using SansEC. Unique electrical signatures are used for damage detection and diagnosis. NASA LaRC has both experimentally and theoretically demonstrated that SansEC sensors can be effectively used for in-situ composite damage detection.

关键词：传感器；SansEC；复合材料；飞机

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Unexploded ordnance (UXO) contamination at former and current Department of Defense sites is an extensive problem. Site characterization and remediation activities conducted with the current state-of-the-art technologies at these sites often yield unsatisfactory results and are extremely expensive to implement. This is due in part to the inability of current technology to distinguish between UXO and nonhazardous items. Newly emerging electromagnetic induction (EMI) sensor technologies offer the ability to robustly distinguish between these two classes of objects. Early versions of these systems have tended to be large and designed for towed operation on open fields with good sky view to provide the necessary quality of geolocation information. The objective of ESTCP projects MR-200807 and MR-200909 was to demonstrate sensor arrays that are capable of reliably retaining the performance of one of these new technologies in a form suitable for use in rugged terrain and other environments where mobility and the viability of traditional positioning technologies are limited. The systems demonstrated in both projects are based on the transient electromagnetic (TEM) induction sensor technology that was developed under ESTCP project MR-200601.

关键词：传感器；电磁感应；地雷探测器；定位；未爆炸的弹药；SERDP收集；SERDP（战略环境研究发展计划）

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After the recent success in jamming wireless improvised explosive devices (IEDs), the threat nowadays has shifted towards the use of buried command wires. A capability to immediately detect the presence of a command wire would be of great value to the troops on the ground. The major challenge of a command wire sensor is to detect the wire in clutter and achieve a high probability of detection without large number of false alarms. The objective of this thesis is to investigate the wire scattering behavior and clutter characteristics through measurements performed in the NPS anechoic chamber. The research has successfully resolved the various multipath components within the anechoic chamber. The transmit-receive coupling between the antennas was reduced through the appropriate use of absorbers. Various wire scattering and clutter characteristics were established through the measurement results. In addition, the measurement results have also demonstrated close-in clutter rejection by utilizing time gating. Recommendations for future work were proposed to gather more data to support the ongoing NPS research on the Command Wire Sensor design.

关键词：传感器；简易爆炸装置；无线通信；发射机接收机；预警系统；命令线传感器

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