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Conference on Sensor Fusion - Architectures, Algorithms, and Applications iii

作者： Steinberg, AN Bowman, CL White, FE ERIM Int Inc Arlington VA 22209 USA

ISBN: (纸本)0819431931

The Data Fusion Model maintained by the Joint Directors of Laboratories (JDL) Data Fusion Group is the most widely-used method for categorizing data fusion-related functions. This paper discusses the current effort to revise and expand this model to facilitate the cost-effective development, acquisition, integration and operation of multi-sensor/multi-source systems. Data fusion involves combining information - in the broadest sense - to estimate or predict the state of some aspect of the universe. These may be represented in terms of attributive and relational states. If the job is to estimate the state of a people (or any other sentient beings), it can be useful to include consideration of informational and perceptual stares in addition to the physical state. Developing cost-effective multi-source information systems requires a method for specifying data fusion processing and control functions, interfaces, and associated databases. The lack of common engineering standards for data fusion systems has been a major impediment to integration and re-use of available technology: current developments do nor lend themselves to objective evaluation, comparison or re-use. This paper reports on proposed revisions and expansions of the JDL Data Fusion model to remedy some of these deficiencies. This involves broadening the functional model and related taxonomy beyond the original military focus, and integrating the Data Fusion Tree Architecture model for system description, design and development.

关键词： Data fusion Data modeling Systems modeling Standards development Data processing Sensors Algorithm development Data analysis Systems engineering Signal detection

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Effects of retro-reflector diameter on testing optical systems

Effects of retro-reflector diameter on testing optical syste...

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Proceedings of the 1999 current developments in optical design and optical engineering Viii

作者： Carter II, Thomas E. Manhart, Paul K. Ellis, Kenneth S. Raytheon Missile Systems Co Tucson United States

In the use of ball bearings as retro-reflectors for testing optical systems in a double pass configuration, care must be taken when choosing the radius of the ball bearing. Using too small a radius can adversely effect the wavefront error as presented by the interferometer. The wavefront error, being a function of wavelength, can be significantly altered due to this ball bearing error, particularly in long wavelength infrared systems tested with a visible light interferometer. This paper is the result of research towards understanding and modeling this error in the presence of spherical aberration.

关键词： optical testing

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Recent developments in hybrid mirror technology for the Next Generation Space Telescope

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Proceedings of SPIE - The International Society for optical engineering 1999年 3749卷 82-83页

作者： Dodson, Kelly J. Mehle, Greg V. Kasl, Eldon P. Composite Optics Inc San Diego United States

The objective of this paper is to report the recent developments in lightweight mirror technology at Composite Optics, Incorporated (COI). The developments are a result of the activities being conducted in support of the Next Generation Space Telescope (NGST) Program. The sponsors of these efforts are the NASA Marshall and Goddard Space Flight Centers. The requirements, design approach, performance, and the technology status for the program are summarized. The emergence of composite materials provides exciting potential for nontraditional, accurate, lightweight, stable, stiff, and high strength mirrors. This evolving technology promises significant improvement in reducing weight, cost and cycle time for future infrared, visible, and x-ray systems. Customers currently embracing composite mirror technology for radiometric use are already reaping substantial system performance benefits. Other customers interested in LIDAR, IR, visible, and grazing incidence x-ray applications are eagerly awaiting successful completion of current technology development and demonstration efforts.

关键词： Mirrors

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Qualitative modeling of complex systems for cognitive engineering

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Proceedings of SPIE - The International Society for optical engineering 1999年 3696卷 240-249页

作者： Perusich, Karl McNeese, Mike Rentsch, Joan R. Purdue Univ South Bend United States

ISBN: (纸本)0819431702;9780819431707

In this paper, the techniques of using fuzzy cognitive maps will be outlined, and demonstrated with an example. Fuzzy cognitive maps will be used as a way to model the causal process in a cognitive system. With such a model interventions to change the dynamics of the system can be developed. In the particular example, the information on a display needed to be improved to support group situation awareness within an AWACS team. A fuzzy cognitive map was developed of the chain of causality that led from the current information structure of the AWACS display to the loss of situation awareness. The map could then be examined to identify ways in which the linkages could be altered to improve situation awareness, and points at which technology could be applied. From this a set of design changes could be recommended.

关键词： Cognitive systems

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Recent developments in hybrid mirror technology for the next generation space telescope

Recent developments in hybrid mirror technology for the next...

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Proceedings of the 1999 'optical Manufacturing and Testing iii'

作者： Dodson, Kelly J. Mehle, Greg V. Kasl, Eldon P. Composite Optics Inc San Diego United States

The objective of this paper is to report the recent developments in lightweight mirror technology at Composite Optics, Incorporated (COI). The developments are a result of the activities being conducted in support of the Next Generation Space Telescope (NGST) Program. The sponsors of these efforts are the NASA Marshall and Goddard Space Flight Centers. The requirements, designs approach, technical challenges, hardware status, and tentative conclusions for the program are summarized. The emergence of composite materials provides exciting potential for nontraditional, accurate, lightweight, stable, stiff, and high strength mirrors. This evolving technology promises significant improvement in reducing weight, cost and cycle time for future infrared, visible, and x-ray systems. Customers currently embracing composite mirror technology for radiometric use are already reaping substantial system performance benefits. Other customers interested in LIDAR, IR, visible, and grazing incidence x-ray applications are eagerly awaiting successful completion of current technology development and demonstration efforts.

关键词： Mirrors

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Autonomous lidar wind field sensor: design and performance

Autonomous lidar wind field sensor: Design and performance

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Proceedings of the 1999 Application of Lidar to current Atmospheric Topics iii

作者： Henderson, Sammy W. Yuen, Eric H. Hannon, Stephen M. Coherent Technologies Inc Lafayette United States

Solid-state coherent Doppler lidar sensors operating at eyesafe wavelengths have broad application to a variety of wind measurement scenarios. We have developed a modular, autonomous, high PRF, diode-pumped coherent lidar sensor that is appropriate for wind profiling at high temporal resolution. This paper describes the design of the sensor, provides examples of high-resolution wind data, and compares the performance with modeling.

关键词： optical radar

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Computer modeling and analysis of veiling glare and stray light in Fresnel lens optical systems

Computer modeling and analysis of veiling glare and stray li...

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Proceedings of the 1999 current developments in optical design and optical engineering Viii

作者： Lamb, David J. Hillman, Lloyd W. Univ of Alabama in Huntsville Huntsville United States

Veiling glare (or flare) occurs in an imaging system when non-image forming flux strikes the focal surface. This light tends to reduce image contrast and can be caused by surface defects, dust, or anything else that might cause light to deviate from its intended imaging path. Fresnel lenses contain many such non-image forming structures as a result of their faceted and discontinuous nature. Sample optical systems for an extensive air shower observatory have been designed that consist of multiple Fresnel lenses. Veiling glare is expected to be significant in these systems, and it is desired to quantify its extent and ramifications. To this end, a series of tests has been performed on the Fresnel lens systems using non-imaging optical analysis software. A method for obtaining veiling glare information efficiently has been developed based upon the manner in which it is measured in real optical systems. By using computer software, the effects that several different parameters have on the veiling glare are analyzed independently without the use of expensive prototypes. It is shown that the amount of veiling glare is highly dependent upon the system configuration and that generalized conclusions regarding veiling glare and the number of Fresnel surfaces in a system are not possible. The analysis methods developed here, however, can be used to efficiently analyze the stray light in any system.

关键词： optical instrument lenses

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Recent advances in guided-wave devices for optical signal processing

Recent advances in guided-wave devices for optical signal pr...

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Proceedings of the 1999 3rd International Conference on optical Information Processing

作者： Armenise, Mario N. Passaro, Vittorio M.N. Armenise, Michele Diana, Roberto Politecnico di Bari Bari Italy

A great research effort has been spent in recent years for the use of guided-wave optoelectronic technologies for signal processing in space applications, because they allow to reduce size, weight, power consumption and system complexity with respect to electronic ones. Based on these motivations, we have conceived, designed and simulated a number of original integrated optical signal processors, such as two-dimensional correlators for imaging reconstruction in Synthetic Aperture Radar (SAR) applications, both airborne and spaceborne (using either a hybrid or monolithic approach), preprocessors for data classification and identification in satellite applications for remote sensing, beam formers and steerers in active phased array antennas (using either the acousto-optic or electrooptic effect), heterodyne spectrum analyzers, and so on. The substrate materials considered for these circuits are both ferroelectric (*** niobate) and iii-V semiconductor materials (*** arsenide and its compounds). Original modelling and numerical techniques have been developed to analyze and design the guided-wave components included in the optical architectures. In this paper, the most significant developments of this research activity are reviewed.

关键词： optical waveguides

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Superlattice quantum cascade lasers

Superlattice quantum cascade lasers

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Conference on In-Plane Semiconductor Lasers iii

作者： Tredicucci, A Capasso, F Gmachl, C Sivco, DL Hutchinson, AL Chu, SNG Cho, AY AT&T Bell Labs Lucent Technol Murray Hill NJ 07974 USA

ISBN: (纸本)0819430986

Novel approaches to the design of inter-miniband quantum cascade lasers with undoped active regions are presented. The applied electric field is compensated across the superlattices, either by exploiting the field generated by extrinsic charges in special modulation-doped injection regions, or with an effective "quasi-electric field" obtained by varying the superlattice period and duty-cycle so that a flat miniband condition is reached. Broadening mechanisms and optical losses introduced by the otherwise needed dopants in the superlattices are thus reduced, dramatically lowering the threshold current densities and improving the temperature performance of the lasers. At the same time the appealing properties of inter-miniband based devices, i.e. automatic population inversion and high current carrying capabilities, are preserved. Room temperature record-high peak (similar to 0.5 W) and average (14 mW) powers are observed for a lambda = 7.6 mu m laser. The lowest threshold current densities reported up to now in quantum cascade lasers at 300 K (J(th) = 45 kA/cm(2)) are also obtained, which translates in very large maximum temperatures for continuous wave operation (160 K). Inter-miniband superlattice structures prove particularly useful in extending laser operation towards longer wavelengths, where the increased optical absorption losses and the reduced radiative efficiency require larger driving currents. This is shown by the realization of a laser with chirped superlattice active regions operating at lambda = 17 mu m, well, beyond the longest wavelength (lambda = 13 mu m) so far demonstrated for conventional quantum cascade lasers based on inter-subband transitions.

关键词： infrared semiconductor lasers bandgap engineering superlattices quantum cascade lasers

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Control design which respects characteristic length scales in smart systems and smart structures

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Proceedings of SPIE - The International Society for optical engineering 1999年 3667卷 202-210页

作者： Baillieul, J. Boston Univ Boston United States

Although there is a mature and continually growing body of knowledge concerning the ways in which the dynamics of fluids and solids depend on characteristic length scales, current theories governing control design do not take explicit account of length scales. Recent research has demonstrated the need to take such considerations into account in designing control systems for smart materials and smart structures in which the goal is to employ small-scale actuators and sensors with characteristic length scales in the micron to millimeter range. For many applications, sensors and actuators will need to be separated by considerable distances (in terms of characteristic length scales). Closed loop feedback designs in this setting may involve communications delays, and both the communications channels and the sensors themselves will typically be relatively noisy. Hence traditional approaches to the design of feedback control laws need to be rethought and modified to work effectively in the noisy, nonlinear, bandlimited world of microelectromechanical systems (MEMS). This paper discusses one approach to a robust, length-scale respecting theory of control based on oscillatory actuation. It includes a brief outline of recent developments in the control of mechanical systems using oscillatory actuation, emphasizing the dependence on characteristic length scales. The principal applications with which we are working are micro-pendulum designs, micro-piston actuators for deformable mirrors as well as micro-valves for the control of fluid-structure boundary layer control.

关键词： Intelligent structures

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