相对辐射定标与相对辐射校正场

相对辐射校正是提高遥感卫星图像质量的一个极其重要的途径,辐射校正场定标是相对辐射定标的一个行之有效的方法。本文在介绍了CCD遥感卫星成像原理和过程的基础上,分析了相对辐射校正的原理,进而阐述了进行相对辐射校正的三种方法。同时,本文还特别针对在轨对地定标探讨了选择相对辐射校正场的方法,并介绍了几个条件优越的相对辐射校正场。     

温度变化环境热线现场校准装置

当热线工作于温湿度变化场合时，其特征参数随之变化。为了保证测量的准确性，热线仪需随环境变化进行校准。本文设计了一种实时热线现场校准装置和遥测遥控系统，适用于野外和恶劣环境下的测量。该仪器在斜拉桥风致振动研究中准确地测量出了台风过境时的参数特性，显示了较强的适用性。     

Best Practice Guidelines for Pre-Launch Characterization and Calibration of Instruments for Passive Optical Remote Sensing

The pre-launch characterization and calibration of remote sensing instruments should be planned and carried out in conjunction with their design and development to meet the mission requirements. The onboard calibrators such as blackbodies and the sensors such as spectral radiometers should be characterized and calibrated using SI traceable standards. In the case of earth remote sensing, this allows inter-comparison and intercalibration of different sensors in space to create global time series of climate records of high accuracy where some inevitable data gaps can be easily bridged. The recommended best practice guidelines for this pre-launch effort is presented based on experience gained at National Institute of Standards and Technology (NIST), National Aeronautics and Space Administration (NASA) and National Oceanic and Atmospheric Administration (NOAA) programs over the past two decades. The currently available radiometric standards and calibration facilities at NIST serving the remote sensing community are described. Examples of best practice calibrations and intercomparisons to build SI (international System of Units) traceable uncertainty budget in the instrumentation used for preflight satellite sensor calibration and validation are presented.     

Automatic Transformation of Curved-to-Flat Calibration Lines by a Normalizer

In high-accuracy swept-frequency insertion-loss testing, antenna-pattern measurement, and many other applications, significant measurement-system output variations are caused by the system itself. These variations can be recorded and subtracted from the measurement results to provide the required accuracy generally by recording system calibration lines with attenuation standards in the test position and reading the measurement results against these calibration lines. However, the procedure is tedious, costly, and does not lend itself to automation. The linearizer is a device for storing the system calibration and correcting for it before displaying the results. With no loss in accuracy, it provides an output curve that can be read on an ordinary rectilinear graph, used to actuate GO-NO GO switches, or automaticaly compare a test piece against a standard. Details of operation and some performance data are given for a particular analog-type linearizer and associated swept-frequency measurement system for insertion-loss or scattering coefficients. The linearizer can readily display a scale of 0.02 dB/inch with adequate stability and reproducibility. Two such linearizers can be used together to display two components of a vector or phase and amplitude, etc. Other applications are discussed and several possible approaches to an ideal system shown.     

机载设备检测和校准需求分析研究

检测和校准是实现机载设备性能参数的量值准确一致、保证产品质量、提升保障效率的基础,科学合理的需求分析则是高效开展检测和校准工作的前提。现阶段由于缺乏相应的需求分析标准和指导规范,工程中存在着检测需求不齐全、参数定义不清晰、指标要求不合理等问题。本文论述了机载设备检测和校准需求分析的内涵与现状,提出了一种合理的需求分析方法、工作流程以及实施建议,可直接应用于工程实践。     

可见光和热红外辐射定标方法浅述

随着遥感技术的发展，遥感影像的应用越来越为人们所关注。而遥感影像的处理成为不可缺少的关键环节。在遥感数据的采集过程中，由于受到仪器本身的误差及自然环境诸多因素的影响，不可避免的产生种种误差。为了获得真实反映地物信息的图像，必须进行纠正。本详细介绍了引起辐射畸变的因素以及各种辐射纠正的方法，并以NOAA为例详细分析了其产生畸变的原因，并着重介绍了三种辐射定标方法：反射率法、辐亮度基法和辐照度基法，结果显示辐照度基法较为理想。     

光散射式数字粉尘测试仪的标定及其应用

环境粉尘浓度的测定一般使用滤膜称重方法测得,该方法费时费力,且不能得到瞬时粉尘浓度的变化。由于光散射式数字式粉尘测试仪性能稳定、灵敏度高,测量方便而广泛的应用于各类测尘应用。文中介绍了光散射式数字粉尘测试仪各项指标的具体标定方法,并结合实际应用,总结了使用过程中应注意的事项。     

鱼眼图像的校正算法

基于鱼眼镜头的全方位视觉系统可应用在很多方面,如全视觉监视、机器人导航等。全方位视觉系统的标定和畸变图像的校正是至关重要的两个部分。本文给出标定鱼眼图像中心和半径的方法,它们算法简单,很容易用软件实现,并通过实验说明它们的有效性。然后用标定得到的参数进行校正。鱼眼成像规律常被用在鱼眼镜头设计中。本文推导出校正模型。基于这些校正模型,得出组合校正模型,并通过实例验证了这种组合校正模型的正确性和有效性。     

面向定量化红外遥感的热电堆探测器定标技术

从红外遥感信息定量化的发展要求出发,分析了测辐射热计、热电堆探测器和热释电探测器的响应特性,选择薄膜热电堆探测器TS-76作为传递标准探测器.搭建高精度光谱响应率定标系统,使用宽波段可调谐激光器和绝对低温辐射计对TS-76探测器的线性、空间均匀性以及重复性进行了标定.按照国际通用不确定度评估规范,对光谱响应率测量结果进行不确定度分析和评估,联合不确定度小于1.5%,并根据实验结果提出实现高精度中远红外辐射定标的技术方案,证明基于热电堆探测器的红外辐射定标技术可以有效缩短标准传递的链路,提高定标的精度.     

激光干涉法进行正弦力校准研究

采用绝对法进行正弦力校准,动态力由安装在振动台上的质量块产生,力值根据力的定义直接溯源到质量、加速度和时间。为了减少测量不确定度,质量块上的加速度分布必须进行准确测量。文中介绍了采用激光干涉法进行动态力校准的原理和信号处理方法,同时介绍了与德国PTB加速度实验室进行加速度测量的比对情况。结果表明,采用所介绍的正弦力校准方法可以提高校准的准确度。     

A collaborative agent-based infrastructure for Internet-enabled collaborative enterprises

The Internet has evolved very rapidly from an information space to a market space over the past few years. There is a tendency towards implementing real-world agent-based applications based on the Internet. This paper presents some results of our recent research work towards an infrastructure for Internet-enabled collaborative agent systems. The infrastructure and the related supporting services, components, prototypes and mechanisms are initially proposed and developed for Internet-enabled collaborative agent systems in all kinds of application areas, but they are primarily targeted for implementing Internet-enabled collaborative enterprises or supply chain management systems. The general collaborative agent system architecture with the basic communication and cooperation services, domain independent components, prototypes and mechanisms are described. The benefits of implementing Internet-enabled collaborative enterprises with the proposed infrastructure are discussed. A case study on multi-plant production planning is presented. Some important implementation issues are discussed.     

明渠堰槽流量计在线校准常见计量问题

目前,在我国尚无明渠流量计在线校准的技术规程或规范,在新时期条件下,全国多地计量机构仍在使用1990年颁布的检定规程,已经不能满足多类型的明渠堰槽流量计在线检定需求。笔者通过长期在检测现场的经验积累,分析了一些较常见的计量误差,对制订符合实际情况的明渠流量计校准规范提出了自己的建议。     

一种无塔校准方法研究

在地面卫星测控系统中,目前使用较多的有塔校准技术具有一定的局限性,为了克服这种局限性,本文针对已有的卫星测控系统设备提出一种无塔校准方法,给出了具体无塔校相和无塔校零的实现方法.     

动态扭矩遥感测试系统校准方法研究

介绍了一种动态扭矩遥感测试系统的工作原理及其应用,提出了针对该类动态扭矩测试系统的校准原理,并介绍了具体的校准方法.     

基于探测器的成象光谱仪绝对辐射定标方法

用一组窄带滤光片、简易辐亮度计和硅光二极管探测器设计了绝对型光谱辐亮度计。精确测量滤光片的光谱透过函数，计算辐亮度计的视场，标定探测器的绝对光谱响应度，成为绝对光谱辐亮度计，用来标定成象光谱和其它光学遥感器，并与基于光谱辐照度灯进行辐射定标的传统方法进行了比较。结果表明，基于探测器进行辐射定标的方法是一种提高光学遥感器定标精度的途径，而且是佐证其它定标方法可靠性的一种手段。     

Model Calibration With Censored Data

The purpose of model calibration is to make the model predictions closer to reality. The classical Kennedy–O’Hagan approach is widely used for model calibration, which can account for the inadequacy of the computer model while simultaneously estimating the unknown calibration parameters. In many applications, the phenomenon of censoring occurs when the exact outcome of the physical experiment is not observed, but is only known to fall within a certain region. In such cases, the Kennedy–O’Hagan approach cannot be used directly, and we propose a method to incorporate the censoring information when performing model calibration. The method is applied to study the compression phenomenon of liquid inside a bottle. The results show significant improvement over the traditional calibration methods, especially when the number of censored observations is large. Supplementary materials for this article are available online.     

水下被动定位系统的校准子系统

减小水下被动动定位系统的定位误差是多年来人们一直关注的一个问题。对于一个实际定位系统，定位误差通常由随机误差和系统误差两部分组成，予以分别对待，可提高定位精度，其中系统误差可对采用系统校准进行消除。本文介绍一个可对实际定位系统实施校准的校准子系统。海上试验的结果表明，定位系统经过校准可有效地减小定位误差，提高定位精度。     

特种经纬仪快速检测与标定系统

传统的经纬仪计量检测设备存在诸多缺点.为改变这一现状,设计了一套特种经纬仪快速检测与标校系统.文章叙述了其软、硬件组成和工作原理,着重阐述了关键问题的解决途径,最后对系统测量不确定度进行了评定.实践证明,系统完全符合要求,能完成特种经纬仪主要项目的快速检测与标校.     

大气温室气体探测激光雷达及其标定技术研究进展

大气温室气体探测激光雷达是温室气体远程探测的重要手段,其探测技术和标定方法成为了各国温室气体探测的研究重点。综述了大气温室气体探测激光雷达技术及其标定方法的发展及应用,并对未来大气探测激光雷达的发展方向进行了展望。     

基于Visual Basic 6.0的功率传感器自动校准系统

从硬件组成和软件设计两方面介绍了功率传感器自动校准系统.着重介绍了该系统的软件设计思路,并就其特点进行说明.该自动校准系统在Visual Basic 6.0环境下完成编程,完整地实现了登录、设备信患登记、测试、报告文件输出及查询功能,使用简便、性能可靠且人机交互良好.