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

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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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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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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current developments in optical design and engineering VII

Current developments in optical design and engineering VII

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current developments in optical design and engineering VII

The proceedings contains 41 papers from the conference on current developments in optical design and engineering VII. The topics discussed include: laser beams;spherical aberrations;bar code scanners;zoom lenses;mirror telescopes;linear detector arrays;streak cameras;laser projection displays;video color mixers;optomechanical design;aspherical mirrors;x-ray optics system;optical resins;high-power lasers;birefringence;light reflection;finite element method and mumerical simulation.

关键词： optical design

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Revisions to the JDL data fusion model

Revisions to the JDL data fusion model

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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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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 18th Congress of the International Commission for Optics (ICO XVIII): Optics for the Next Millennium

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

关键词： Mirrors

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

Control design which respects characteristic length scales i...

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Proceedings of the 1999 Smart Structures and Materials - Mathematics and Control in Smart Structures

作者： Baillieul, J. Boston Univ Boston MA United States

关键词： Intelligent structures

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Advanced optical sensor performance in transmission and distribution applications

Proceedings of the IEEE Power Engineering Society Transmissi...

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Proceedings of the IEEE Power engineering Society Transmission and Distribution Conference 1999年 1卷 259-265页

作者： Cruden, A. Michie, W.C. Niewczas, P. Madden, W.I. McDonald, J.R. Andonovic, I. Univ of Strathclyde Glasgow United Kingdom

This paper reports on recent developments within research into optical fibre based voltage and current measurement equipment for metering and protection applications. Several parameters (thermal variations, intensity fluctuations due to mechanical disturbance, electronic noise) are known to influence the performance of these sensors and this paper summarises an analysis of the effect of such disturbances providing design criteria for the realisation of protection and metering class OCTs. Laboratory trials have shown that the compensation schemes devised reduce vibration errors by 20 to 30 dB and compensate for temperature induced drift to better than 0.1%. Extended engineering evaluation field trials of both OCT and OVT devices within a three phase 132 kV installation have been undertaken over the past two years. Details of these trials are presented to provide an appreciation of the potential difficulties which may be encountered and the benefits which may be derived.

关键词： optical sensors

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Erratum: current developments in optical design and enginneering VII (Proceeding of SPIE - The International Society for optical engineering)

Proceedings of SPIE - The International Society for Optical ...

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Proceedings of SPIE - The International Society for optical engineering 1998年 3429卷 312-312页

作者： Fisher, Robert E. Germann, Lawrence M. Hatheway, Alson E. McConnell, Malaehy Smith, Warren J.

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Advanced optical sensor performance in transmission and distribution applications

Advanced optical sensor performance in transmission and dist...

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IEEE PES Transmission and Distribution Conference and Exposition

作者： A. Cruden W.C. Michie P. Niewczas W.I. Madden J.R. McDonald I. Andonovic Rolls-Royce University Technology Centre in Power Eng. University of Strathclyde Glasgow UK Optoelectronic Division Department of Electrical Eng. University of Strathclyde UK

This paper reports on recent developments within research into optical fibre based voltage and current measurement equipment for metering and protection applications. Several parameters (thermal variations, intensity fluctuations due to mechanical disturbance, electronic noise) are known to influence the performance of these sensors and this paper summarises an analysis of the effect of such disturbances providing design criteria for the realisation of protection and metering class OCTs. Laboratory trials have shown that the compensation schemes devised reduce vibration errors by 20 to 30 dB and compensate for temperature induced drift to better than 0.1%. Extended engineering evaluation field trials of both OCT and OVT devices within a three-phase 132 kV installation have been undertaken over the past two years. Details of these trials are presented to provide an appreciation of the potential difficulties which may be encountered and the benefits which may be derived.

关键词： optical sensors Protection optical fibers Voltage current measurement Fluctuations optical noise Mechanical sensors Thermal sensors Performance analysis

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