利用TGO软件进行点校正求解坐标转换参数的方法

坐标转换包括大地坐标与空间直角坐标之间的相互转换、大地坐标与高斯平面坐标的相互转换、换带计算、国家不同坐标系统之间的坐标相互转换、以及国家坐标与地方独立坐标之间的相互转换。本文详细介绍了如何利用tgo软件中点校正来求解坐标转换参数的方法,可供测绘界同仁在工作中加以参考。     

海洋物探坐标转换软件的研究与开发管理

本文论述了海洋物探和工程测量中所运用到的不同坐标系统及不同地图投影方式之间的坐标转换方法。其主要内容分为两个方面:一是同一坐标系统下不同坐标之间的相互转换;二是不同坐标系统之间的相互转换。深入研究了在高斯投影和UTM投影情况下WGS-84、北京54、西安80三种坐标系统间平面坐标与大地坐标的转换模型和算法,并用VB程序设计语言实现了这些模型和算法。     

相干探测在激光通信系统中的应用

与微波通信相比,空间激光通信系统具有传输速率高、抗干扰和抗截获能力强、轻小型化等突出优点,使其在星际、军事通信领域具有广阔的应用前景根据空间激光通信发展现状和需求分析,对相干激光通信系统的工作原理和特性进行简要介绍,阐述了空间相干激光通信系统中的部分关键技术,系统的设计方法简单可靠,具有很大的推广价值。     

多投影大屏幕拼接显示系统中投影仪颜色空间转换模型研究

为了更好地发挥投影仪在大屏幕拼接显示系统中的作用,需要对投影仪的颜色系统进行深入研究,使之达到颜色一致的效果。以2台投影仪组成的拼接显示系统为例,比较了阶调曲线法、颜色主刺激值修正算法和BP神经网络在投影仪颜色空间转换过程中的特点,得出了BP神经网络是投影仪颜色空间转换的最优模型,可推广应用于同类型颜色空间转换模型的研究。     

数字电影采集转换及利用

本文介绍了一个基于MAC平台的数字采集转换系统,该系统可以实现对以数字高清磁带及DPX数字中间片为介质的电影的采集转换及利用。详细介绍了系统组成所需的设备、使用的软件以及在使用过程中遇到的困难与获得的经验。从技术角度阐述了基于MAC平台数字高清磁带的采集,DPX数字中间文件的编码转换以及数字视频文件DCP打包的实现。     

射线数字成像检测仪的光电系统设计

设计了射线数字成像检测仪的光电系统,包括转换屏、光路、CCD相机以及计算机处理电 路等。采用CsI(Tl)单晶闪烁体将X射线图像转换为可见光图像,用科学级CCD将光图像转换为电信号,利用计算机并行口对图像进行采集. 实验结果证明图像质量优于像增强器组成的成像系统,适用于要求高质量成像检测的场合。     

数字电影采集转换及利用

本文介绍了一个基于MAC平台的数字采集转换系统,该系统可以实现对以数字高清磁带及DPX数字中间片为介质的电影的采集转换及利用。详细介绍了系统组成所需的设备、使用的软件以及在使用过程中遇到的困难与获得的经验。从技术角度阐述了基于MAC平台数字高清磁带的采集,DPX数字中间文件的编码转换以及数字视频文件DCP打包的实现。     

基准转换标准器在多系统集成中的应用

使用经纬仪、激光跟踪仪进行协同测量时需要对不同测量系统的测量基准进行基准转换,传统基准转换手段较为繁琐耗时。针对此问题,设计了一种新型便携式基准转换标准器,该标准器由基准转换组件、转向组件和三脚架组成,通过基准板上的测量靶点及立方镜构建坐标系,实现基准转换。经验证:该标准器在不同姿态下的平均位置偏差小于0.01 mm,利用基准转换标准器验证了经纬仪系统定位孔中心点的测量偏差均小于0.06 mm,立方镜法矢量的平均绝对偏差小于0.0043°。结果表明,该标准器操作方便快捷,能够满足不同工况下经纬仪与激光跟踪仪协同测试的基准转换需求,具有应用推广价值。     

不同坐标系下界址点坐标与宗地面积的转换计算

为确立不同坐标系统之间的转换关系,结合地籍工作中的实际应用,本文提出了一种基于赫尔默特变换模型的坐标转换和精度评价的方法,并利用数学知识,讨论不同坐标系统宗地面积转换和计算面积变形的方法.     

波长转换装置在投影光源系统中的应用

波长转换装置应用于投影光源系统,是投影市场在LED光源和纯激光光源之后基于低成本、高亮度、长寿命、低功耗等的追求,做出的进一步尝试和发展,本文主要以波长转换装置应用于投影光源系统的相关专利申请为研究对象,对其全球专利申请进行了统计和分析,包括申请量趋势、国别分布、申请人分布、专利技术分支及功效,并根据技术功效对专利技术发展路线进行了梳理,形成波长转换装置应用于投影光源系统领域的技术发展脉络,以期对其技术研发方向提供参考。     

一种双源光外差测速技术

本文报道一种双源光外差测速技术,不同源的两束激光分别用于探测和本振参考,借助多普勒效应测量运动表面的速度.根据探测光和参考光之间的频率高低关系,双源光外差测速技术分为下变频和上变频两种工作模式.下变频模式可以将高速信号频率降低,使一般带宽示波器能够满足l0 km/s以上超高速度的测量要求,彻底解决超高速测量对超高带宽的...     

激光多普勒效应微纳测量技术的研究

研究MEMS系统中可动构件(膜、梁、梳、面、弹簧)在承受压力、弯曲等机械负荷及热负荷下的性能，重要途经是测量其在各种条件下的运动量(振动、位移等)．提出了一种MEMS构件微小振动、位移测量系统，采用外差法激光多普勒技术，通过对信号的频谱分析，确定了信号处理单元的适宜频带宽度．对调相多普勒跟踪信号进行相干解调及频率／电压转换，可以实时地得到被测的速度、位移、加速度、频率等参量．实现的测量分辨力为20nm．     

基于DSP的频谱分析型激光多普勒信号处理器的研究

为了提高激光测速系统中信号处理速度,获取更高的测量精度和实时检测能力,本文从硬件结构、传输策略和试验结果入手,提出了利用DSP芯片作为频率分析处理器的多普勒测速系统.通过对A/D控制策略,光电数据采集压缩,DMA传输和DSP处理器中的FFT谱分析和频谱校正算法的研究和对数变频模式模拟电压信号测量试验,实现了多普勒信号处理器在显示采样频率为7MHz,速度显示间隔为0.3ms的实时检测和频率细化能力.     

Compensation of FM-to-AM conversion in high-power lasers

FM-to-AM conversion in the ninth beam of the Shen Guang II laser system with sinusoidal phase-modulated spectra is calculated and analyzed. The simulations show that the intensity modulation at 3ω is much more serious compared to the other wavebands and it is mostly induced by the frequency conversion system rather than the amplification chain. The compensation effects of FM-to-AM conversion in the frequency conversion system by angular dispersion grating and cascaded crystals are numerically simulated and compared. Compared to the cascaded crystals, the angular dispersion grating could maintain higher frequency conversion efficiency with wide spectral width and offer a higher dynamic range of compensation effectiveness versus fundamental laser intensity. Combined with a precompensation filter before the amplification chain, FM-to-AM conversion at 3ω could be eliminated.     

An object-oriented neutral feature model for feature conversion

This paper describes the application of neutral features to facilitate feature conversion. Feature conversion among various applications is achieved through a two-way conversion process. When an application modifies its own features, the corresponding neutral features will be adjusted. This modification will be propagated to all the other applications through the conversion process. A prototype feature conversion system has been established. The system currently supports the design and manufacture of prismatic machined parts. Three applications are defined: design application, machining planning application and set-up planning application. Each application has its own set of application features. Object oriented technology is employed in system development. The structures of the neutral features and application features are developed using the object-oriented technique. The development of the representation schemes and the corresponding algorithms are divided into box-shaped and non-box-shaped. Object-oriented messages for the maintenance of both the box-shaped and non-box-shaped feature models are developed. The process of conversion from an application feature to neutral features is developed using the object-oriented technique; algorithms are implemented in the form of object-oriented messages. The conversion from neutral features to application features is handled by the rule-based reasoning approach.     

变频调速技术在集中采暖循环水系统中的节能应用

分析了变频调速技术应用于集中采暖循环水系统中存在的巨大节能潜力,介绍了变频控制系统的组成和基本原理,阐述了变频控制系统的基本特点,并以实例计算说明了其节能效果和经济效益.     

直流变频装置在纸机传动控制系统中的应用

本文针对纸机控制的特点,从当前国内外纸机控制系统的现状出发,对其自控系统进行深入研究,设计了3300／600纸机直流母线变频传动控制系统。并详细介绍了整个直流变频传动控制系统,对传动系统控制器进行了深入的比较,给出具体设计方案,提供详尽的原理图,并完成了整个系统的各方面调试工作。     

Testing methodologies for analog-to-digital converters

A theoretical approach and an experimental test system devoted to introducing a set of parameters based on Walsh functions and conformed to characterize the transfer function of analog-to-digital converters are presented. Building on the previous work, the authors propose an enhanced system that provides better accuracy in the evaluation of the performance of conversion devices under dynamic conditions. The theory covers an introductive approach to generalize the conversion processes and employs a powerful purpose-oriented tool to understand their in-depth operativity. The error parameters are defined by mathematical algorithms based on Walsh functions and related transform, while their properties are correlated to a standard reference input, a triangular waveform provided by the system. This methodology opens the wave towards the introduction of standard techniques in testing conversion devices     

Accurate velocity measurements of AFM-cantilever vibrations by Doppler interferometry

Doppler velocimetry is widely used in the measurement of nanometre resonance vibrations of micro-electromechanical systems (MEMS). It has excellent sensitivity and precision, but typical engineering applications do not require traceability of these velocity measurements to the SI system. While Doppler velocimetry is, in principle, easy to make traceable to the velocity of light, in practice a frequency-to-voltage conversion in common commercial instruments breaks this traceability unless calibrated. Typically, though, calibration is performed at a much lower frequency than those typical of MEMS devices, without the guarantee that the calibration is applicable in this higher frequency regime.

We present a method of traceable measurement of velocity in terms of the velocity of light, valid for the range of frequency and nanometre amplitudes typical of MEMS devices driven to resonance vibration. This is achieved by analysis of sideband amplitudes in the interference spectrum before demodulation of the Doppler signal. These sideband amplitudes can conveniently be measured using a benchtop spectrum analyser, a piece of widely available electrical test equipment. We illustrate the method with measurements on individual AFM cantilevers. In combination with cantilever calibration methods based on MEMS devices this method enables traceable calibration of those cantilevers employed for the measurement of pico- and nanonewton forces between individual biomolecules.     

编码超声血流多深度检测

血流信息检测及其成像因其独特的优势,在临床上得到广泛应用。但常规经颅多普勒超声系统仍采用模拟和数字电路结合的传统技术,这类系统容易受到外界干扰且不能进行多深度检测。文章设计出一种全数字多普勒超声血流检测系统方案,弥补了传统模拟系统存在的问题。多普勒仿体和人体实验结果表明,该系统能够进行多深度检测,确定血管的深度;同时,还提高了检测灵敏度、超声穿透力和系统成像分辨率。