经验加速度补偿对HY-2A卫星精密定轨的影响     

孔巧丽  郭金运  赵春梅 《测绘科学》2016,(8):165-169

针对HY-2A卫星定轨中存在系统误差的问题,该文提出了加入经验加速度补偿系统误差。为了获得HY-2A卫星的高精度轨道,采用星载DORIS距离变率数据探索了经验加速度对定轨精度的影响。探讨了1d、3d和7d作为经验加速度周期的定轨精度差异,分析了3d作为经验加速度周期时在径向、法向和切向3个方向设置经验加速度对定轨精度的不同影响。研究结果表明:HY-2A卫星在径向和切向不存在系统误差,而在法向存在系统误差,因而在法向设置经验加速度进行力学模型补偿能够取得较好的定轨结果;3d作为经验加速度的补偿周期较为合适,不仅能够减少解算参数个数,缩短计算时间,而且径向定轨精度可达到1.00cm,满足HY-2A卫星精密定轨需求。  相似文献   

天山南麓库车晚新生代褶皱-冲断带   总被引：2，自引：1，他引：1  

文磊  杨海军  李曰俊  彭更新  杨宪彰  黄智斌  罗俊成  张强 《岩石学报》2016,32(3):847-855

库车褶皱冲断带位于天山南麓,由近东西走向的多条构造带组成。三叠系暗色泥岩、侏罗系煤层、古近系库姆格列木组膏盐层和新近系吉迪克组膏盐层构成库车褶皱冲断带的区域性主滑脱面。褶皱冲断带底面由北向南逐渐抬高。褶皱冲断带主体发育盖层滑脱-冲断构造(薄皮构造),基底卷入型冲断构造(厚皮构造)见于北缘的根带。新生界膏盐层之上构造变形以滑脱褶皱为特色,之下以冲断构造为特色。库车褶皱冲断带是印度-亚洲碰撞远程效应下,(南)天山晚新生代造山过程的产物。褶皱冲断带构造变形的动力来源主要是造山楔向塔里木盆地推进所形成的挤压构造应力。褶皱冲断带构造变形的起始时间为约23Ma,构造变形具有阶段式加速的特点,已经识别出约23Ma、约10Ma、5~2Ma和1~0Ma共4个变形加速期。褶皱冲断带的演化过程为前展式,褶皱冲断带前锋向南推进的同时,后缘持续变形。  相似文献   

Estimation of peak relative velocity and peak absolute acceleration of linear SDOF systems     

Jianwei Song Yi-Lun Chu Zach Liang George C. Lee 《地震工程与工程振动(英文版)》2007,6(1):1-10

In the seismic analysis and design of structures, the true velocity and absolute acceleration are usually approximated by their corresponding pseudo-values. This approach is simple and works well for structures with small damping (say, less than 15%). When the damping of a structure is enhanced for the purpose of response reduction, it may result in large analysis and design errors. Based on theory of random vibration and the established mechanism of seismic response spectra analysis, a method is developed (1) to predict the relative velocity spectra with any damping ratio level directly from the 5% standard pseudo-acceleration spectrum; and (2) to estimate the peak absolute acceleration. The accuracy of both is validated by using two selected ensembles of ground motion records.  相似文献   

2007年宁洱6.4级地震强震动观测记录   总被引：2，自引：0，他引：2  

崔建文  李正光  赵云旭 《地震研究》2007,30(4):384-388

"十五"期间建设并投入试运行的中国数字强震动台网云南区域台网有20多个强震动台站记录到宁洱6.4级地震产生的地面运动。记录的最大峰值加速度为431.2cm/s2,这是我国大陆自开展强震动观测以来在一次强震中同时获取记录最多的一次,初步展现了"十五"强震动台站建设的成效。  相似文献   

打桩振动对周围环境的影响     

黄同林 《福建地质》2007,26(1):52-56

在城市建筑物密集区进行振动沉管施工,引起震动对周围环境的影响已成为地基处理施工中一个突出的问题,通过对某项工程水泥粉煤灰碎石柱(CFG)桩施工振动对周边建筑物影响的测试和分析,对地基处理方法的选型及如何有效减轻和控制施工振动对周围环境的影响,均具有一定意义。  相似文献   

Seasonality and duration in extreme value distributions of significant wave height     

Fernando J. Mndez  Melisa Menndez  Alberto Luceo  Raúl Medina  Nicholas E. Graham 《Ocean Engineering》2008,35(1):131-138

This paper presents a statistical model to characterize the long-term extreme value distribution of significant wave height, conditioning to the duration of the storm and accounting for seasonality. A time-dependent version of the peak over threshold (POT) approach is used to build the model, which is then applied to specific reanalysis time series and NOAA buoy records. The model considers the annual and semiannual cycles which are parameterized in terms of harmonic functions. The inclusion of seasonal variabilities substantially reduces the residuals of the fitted model. The information obtained in this study can be useful to design maritime works, because (a) the model improves the understanding of the variability of extreme wave climate along a year and (b) the model accounts for the duration of the storm, which is a key parameter in several formulations for rubble mound breakwater design.  相似文献   

航空矢量重力测量中科里奥利加速度对测速精度要求分析          下载免费PDF全文

王丽红  张传定 《海洋测绘》2008,28(2):1-4

首先论述了航空矢量重力测量中科里奥利加速度的计算模型,给出了科里奥利加速度改正对水平、垂直速度要求的分析模型。数值表明,在低纬地区欲达到1mGal的科里奥利加速度的精度,要求速度的精度为5cm／s左右;依据实测数据,目前GPS测得的载体速度精度为0．3mm／s,完全能够满足航空矢量重力测量对科里奥利加速度改正的要求。  相似文献   

EM算法的BFGS和DFP联合加速算法     

王胜帅  单锐  陈静  郑鹏辉 《成都信息工程学院学报》2008,23(3):337-339

使用非线性规划中的变度量法BFGS算法和DFP算法给出了一种新的加速EM算法收敛的方法。  相似文献   

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郑水明  王岚  黄江  王平 《大地测量与地球动力学》2008,28(6):73-76

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A new method to determine the gravity field of small bodies from line-of-sight acceleration data     

Nian-Chuan Jian  Jian-Guo Yan  Jin-Song Ping  Jean-Pierre Barriot  J.Alexis P.Rodriguez 《天文和天体物理学研究(英文版)》2019,(3):155-164

We present a new method to derive line-of-sight acceleration observables from spacecraft radio tracking data. The observables can be used to estimate the mass and gravity of a natural satellite as a spacecraft flyby. The corresponding observation model adapts to one-way and two/three-way tracking modes. As a test case for method validation and application, we estimated the mass and degree two gravity field for the Martian moon Phobos using simulated tracking data when the spacecraft Mars Express flew by Phobos on 2013 December 29. We have a few real tracking data during flyby and they will be used to confirm raw data simulation. The main purpose of this paper is to demonstrate the method of line-of-sight acceleration reduction from raw tracking data and the feasibility to estimate mass and gravity of a natural satellite using this type of observable. This novel method is potentially applicable to planet and asteroid gravity field studies combined with Doppler tracking data.  相似文献