共查询到20条相似文献,搜索用时 31 毫秒
1.
针对星载分布式干涉合成孔径雷达(InSAR)系统空间几何构形,全面分析了卫星状态误差、干涉基线误差、干涉相位误差、时间、频率和波束三同步误差以及斜距测量误差等分布式InSAR测高误差源,给出了系统测高误差总的传递关系.以三大同步误差为重点,推导了各误差源到高程误差的理论传递模型,给出了分布式InSAR系统的理论评价方法.基于分布式InSAR全过程仿真平台,提出了一种通过构造一定平均坡度的典型场景和自然场景来进行系统仿真的实验评价新方法.通过理论和系统仿真实验两种评价方法的结合,使得分布式InSAR系统的性能评价更加全面、真实. 相似文献
2.
Conventional error diffusion halftoning uses a causal error filter. We propose the iterative error diffusion algorithm by extending the error diffusion to accommodate noncausal error filters. We realize the importance of the phase response of the error filter in the error diffusion halftoning method, and demonstrate it using examples. Iterative error diffusion is able to realize a zero phase error filter. We also trace a drawback of error diffusion to the shape of the error filter, and provide a remedy. The results obtained using a zero phase error filter in the iterative error diffusion algorithm are, in our opinion, superior to the error diffusion halftones. 相似文献
3.
4.
5.
6.
7.
8.
结合惯性导航基本原理,经过推导得到捷联惯导系统初始对准误差对导弹位置误差影响的误差方程。利用Simulink搭建导弹飞行模型框图,通过蒙特卡罗仿真,产生初始对准误差随机数,计算导弹位置误差。分析初始对准误差对导弹位置误差的影响。为导弹武器系统的设计、武器系统误差分析和末制导目标截获概率的计算提供帮助。 相似文献
9.
捷联惯性系统的误差及其特性分析 总被引:2,自引:1,他引:1
从捷联惯性系统的误差源出发,根据系统的误差方程,通过理论分析和仿真,阐述了各惯性传感器误差和初始误差对系统的影响,并在几种动态环境下对系统的误差特性进行了仿真。结果表明:与静态误差特性相比,系统的误差特性发生了较大的变化。 相似文献
10.
11.
为了实现非球面面形误差的高精度测量,研究了基于部分补偿原理的数字莫尔移相干涉技术中回程误差的消除方法。通过建立实际干涉仪和建模理想干涉仪,并运用数字莫尔移相干涉技术,获得实际干涉仪像面与被测非球面面形误差相关的波前;分析了该测量系统的误差,提出采用逆向优化法消除大面形误差时的回程误差实现被测非球面的面形误差检测。实验结果表明:与轮廓仪结果比对,面形误差较小时二分之一法重构面形误差,峰谷值和均方根值分别优于/20,面形误差较大时运用逆向优化法消除回程误差,重构的非球面面形误差峰谷值和均方根值偏差均优于/5。基于逆向优化法的部分补偿数字莫尔移相干涉非球面检测,有效消除了大面形误差时的回程误差,可实现高精度的面形误差重构检测。 相似文献
12.
为了克服当前光子晶体光纤传感器误差校正方法存在的不足,提出了模式识别的光子晶体光纤传感器误差校正方法。首先分析光子晶体光纤传感器误差产生原因,然后采集光子晶体光纤传感器误差历史数据,引入模式识别技术对光子晶体光纤传感器误差进行学习,并对光子晶体光纤传感器误差进行校正,最后并与其它方法进行了光子晶体光纤传感器误差校正仿真实验。结果表明,本文方法提升了光子晶体光纤传感器误差校正准确性,能够刻画光子晶体光纤传感器误差变化趋势,光子晶体光纤传感器误差校正效果明显好于对比方法,验证了本文方法的优势。 相似文献
13.
针对软交换系统软件错误产生的原因及呼叫过程每个步骤可能产生错误的原因进行了分析。基于分析结果提出了分层系统结构优化方案以避免错误的产生,并针对无法避免的错误提出了系统纠错和拥塞纠错概念。根据纠错机制,给出了软交换系统软件架构设计、系统纠错和拥塞纠错等方面解决方法。对纠错机制进行了实际测试,实现了系统错误的处理。 相似文献
14.
Novel roundoff error bounds for floating-point addition and multiplication are introduced. The error bounds are found to be tighter than conventional error bounds. Tight error bounds are of practical interest as they allow the reduction of intermediate result word lengths, consequently reducing the complexity of dedicated arithmetic hardware. The use of the proposed error bounds is demonstrated by deriving a roundoff error bound for polynomials when used as interpolators 相似文献
15.
发射原点作为远程飞行器试验中制导工具系统误差分离的重要参数,直接影响制导工具系统误差分离结果。对发射原点误差对制导工具系统误差分离的影响进行了分析,推导了发射原点误差对遥外差和制导工具系统误差分离的影响公式。仿真计算结果证明了文中对发射原点误差影响制导工具系统误差分离的分析结果的正确性。 相似文献
16.
Tsai JZ Will JA Hubbard-Van Stelle S Cao H Tungjitkusolmun S Choy YB Haemmerich D Vorperian VR Webster JG 《IEEE transactions on bio-medical engineering》2002,49(5):484-494
We identified the error sources in a system for measuring tissue resistivity at eight frequencies from 1 Hz to 1 MHz using the four-terminal method. We expressed the measured resistivity with an analytical formula containing all error terms. We conducted practical error measurements with in-vivo and bench-top experiments. We averaged errors at all frequencies for all measurements. The standard deviations of error of the quantization error of the 8-bit digital oscilloscope with voltage averaging, the nonideality of the circuit, the in-vivo motion artifact and electrical interference combined to yield an error of +/- 1.19%. The dimension error in measuring the syringe tube for measuring the reference saline resistivity added +/- 1.32% error. The estimation of the working probe constant by interpolating a set of probe constants measured in reference saline solutions added +/- 0.48% error. The difference in the current magnitudes used during the probe calibration and that during the tissue resistivity measurement caused +/- 0.14% error. Variation of the electrode spacing, alignment, and electrode surface property due to the insertion of electrodes into the tissue caused +/- 0.61% error. We combined the above errors to yield an overall standard deviation error of the measured tissue resistivity of +/- 1.96%. 相似文献
17.
星点图像坐标的准确性与数字天顶仪的定位精度紧密相关。根据数字天顶仪成像原理,严格推导出星点图像坐标表达式,在此基础上推导了星点图像坐标在4个误差因素及综合误差下的误差方程,分析结果表明各误差之间相互独立。通过仿真4个误差因素及综合误差情况下的星图数据进行分析,仿真结果表明:焦距误差与转位误差对各星点图像坐标的影响各不相同,焦距引起的坐标变化值x和y相对其平均值的最大波动值分别为2.38、3.04 pixel;转位误差引起的坐标变化值x和y相对其平均值的最大波动值为1.06、1.41 pixel;光轴倾斜误差与主点偏移引起的星点图像坐标变化是整体性偏移。另外,提出了一种误差参数求解的方法,利用解算出来的误差参数对星点图像坐标进行补差,数字天顶仪的定位经度精度提高了约1.98 m,纬度精度提高了约1.65 m。 相似文献
18.
19.
Davis C.H. Jiang H. Wang X. 《Geoscience and Remote Sensing, IEEE Transactions on》2001,39(11):2483-2489
The spatial variability of elevation errors in high-resolution digital elevation models (DEMs) derived from stereo-image processing is examined. Error models are developed and evaluated by examining the correlation between various DEM parameters and the magnitude of the observed DEM vertical error. DEM vertical errors were estimated using a dataset of more than 51000 points of known elevation obtained from a kinematic Global Positioning Satellite (GPS) ground survey. Elevation variability and the quality of the stereo-correlation match over small spatial scales were the dominant factors that determined the magnitude of the DEM error at any given location. The error models are strongly correlated with the magnitude of the DEM vertical error and are shown to adequately represent the full range of the observed error. The error models are used to estimate the magnitude of the vertical error for every point in the DEMs. The models are then used to predict the overall error in the DEMs. The results demonstrate that the error models can accurately quantify and predict the spatial variability of the DEM error 相似文献
20.
计算机控制光学元件面形修复(Computer Control Optics Surfacing, CCOS)需要通过计算驻留时间,反复迭代,从而得到更小的误差。因为干涉测试过程中边缘面形测试的条件限制,只能得到更小孔径的误差分布图,所以面形的预测性延拓是磁流变抛光、离子束抛光等加工方式的基础技术。基于面形误差的相似性和边缘误差的连续性为出发点,开发了采用基于Zernike拟合和Laplace方程配合的方法进行光学元件面形误差边缘延拓技术。开展了相关理论分析,设计相关算法并实现了延拓过程,延拓结果符合面形相似形和连续性的加工要求,采用直接法和残余误差计算方法对延拓结果进行评估,结果证明了延拓方法的有效性。 相似文献