查询词典 direction cosine

Then,the cosine value of central angle between the spacecraft and the descending node is solved by using cosine theorem of spherical geometry to avoid the cumbersome solving process by judging the flight direction of a satellite and the latitude of sub-satellite point in an original calculation model of image motion speeds.

通过球面几何的余弦定理直接求解航天器与降交点相对地心夹角的余弦值，避开了原像移速度计算模型中通过判断卫星飞行方向和星下点纬度来求解航天器与降交点相对地心夹角余弦值这一过程。

The information Radon coefficient wrap-around of the line on a finite field was caused by the modular arithmetic so that the Radon coefficient information in the periodic oscillations direction was processed with discrete cosine transformation, and other direction information was processed with wavelet analysis in order to reduce the wrap-around of rebuilding information. At the same time, according to the characteristic of the noise, one kind of denoising threshold selection plan was proposed.

正交有限脊波分析处理信息时，有限域平面上的直线由于模运算的存在而引起信息Radon系数的卷绕，为此，对Radon系数周期振荡方向的信息采用离散余弦变换处理，其他方向信息采用小波分析处理，以减少卷绕对信息重建影响；同时，结合图像信息中噪声的特点，提出了一种去噪浮动阈值的选取方案。

For every ULA, the wide-band signals are sampled in spatial and temporal, then 2-D discrete Fourier transform is carried out. A projection operation on 2-D representation of wide-band signals is applied in the spatial-temporal frequency domain. The direction cosine relative to the ULA axes is estimated by MUSIC algorithm.

该方法采用3个共面的均匀线阵，每一均匀线阵对宽带信号空间采样，然后进行空时二维DFT变换，在空时频率域对宽带信号进行投影变换，用MUSIC算法实现宽带来波信号方向余弦的估计。

The forward kinematics is analyzed by choosing one of the mechanisms which have one, two,three or zero angle constraint.Wherein,3-CCC is a new parallel mechanism which has three angle constraints and three distance constraints, Calay\'s formular and direction cosine matrix are used to describe the rotation matrix respectively.By setting Dixon\'s and Sylvester\'s resultant with the three angle constraint equations respectively and using parameters replacement to deal with the distance constraint equations,the 64 order input-output equation of the forward kinematics is obtained under both of the methods.Numerical example confirms these theretical results and the motion simulation is shown in VC++ by integrating OpenGL.

3对高小山提出的广义并联机构进行了研究，以其中具有角度约束的并联机构进行了分析，选取具有一个、两个、三个和零个角度约束类型中各一个机构进行了运动学正解求解，其中3-CCC是一种全部由圆柱副构成的具有三个线线角度和三个距离约束的新型并联机构，文中分别用Calay公式和方向余弦两种旋转矩阵建模方法对其位置正解进行了分析，通过对三个角度约束方程分别构造Dixon结式和Sylvester结式，以及对三个距离约束方程进行变量代换分别导出了位置正解输入输(来源：4040ABC论文网www.abclunwen.com)出方程，得出64组位置正解，并使用数值算例验证了其全部根。

Earthworks zero line is determined by constructing the spatial gridding curved surface model of the original terrain and the field leveling design terrain by digital elevation mode. The DEM data of original terrain are obtained by actual measurement. The mathematical correlation is deducted to demonstrate the relationship between the coordinates of any point on spatial line and the direction cosine by the spatial linear equation. DEM data obtaining program is compiled by Fortran9.0 and it is applied automatically to obtain the DEM data of field leveling design terrain.

目的 利用数字高程模型(digital elevation model， DEM)构造原始地形和场平设计地形的空间网格曲面模型，确定土方工程中的零线方法通过实测提取原始地形DEM数据；依据空间直线方程，推导空间线段土任意点的坐标与方向余弦的数学关系式，采用Fortran90程序设计语言编写DEM数据提取程序，自动提取场平设计地形DEM数据；应用Surfers8.0和MapInfo软件构造规则的网格空间曲面模型并导出网格节，点数据；擦除场平设计范围外数据。

On moving base, a new initial alignment algorithm for strapdown inertial navigation system is proposed. In the algorithm, two special inertial frames, the initial-time inertial frame (i0 frame) and the initial-time SINS body inertial frame (ib0 frame), are defined and are selected as calculation reference frames, then, the calculation of initial alignment direction cosine matrix is expanded into three parts:(1) the DCM between i0 frame and the navigation frame will be easily obtained via local geographical coordinates and initial alignment time;(2) attitude updating using gyro samples gets the DCM between SINS frame and ib0 frame;(3) by explaining SINS specific force equation in SINS body frame, the relation between velocity log, accelerometer measurement and gravity acceleration is established to achieve the constant DCM from ib0 frame to i0 frame.

在运载体运动情况下，提出了一种适用于捷联惯导系初始对准的新算法，该算法以惯性空间为参考基准，即建立了初始时刻惯性坐标系（i0系）和初始时刻捷联惯组惯性坐标系（ib0系）两个惯性坐标系，将初始对准姿态矩阵的实现分解为三部分：（1）通过地理位置和初始对准时间求解i0系至导航坐标系的变换矩阵；（2）使用姿态更新算法实时计算捷联惯组相对于ib0系的变换矩阵；（3）通过惯导比力方程变形，获得测速仪辅助测量、加速度计输出和重力加速度之间的关系，从中可以求解出从ib0系至i0系的常值变换矩阵。

This present algorithm further distinguishes itself through sufficiently utilizes the advantage that the vector sensors provide from other beam space DOA algorithms in several regards: 1 beams are formed in the vector-field domain; 2 produce at moderate signal-to-noise ratio estimation performance comparable to the traditional scale array methods;3 these vector-field beams are formed blindly using no apriori source information and coarse estimates of the direction cosine are derived to start off MUSICs iterative search so it demand less computation; 4 deploy agilely , since the fact that the output channel is various .

本文提出了矢量传感器阵列的自适应综合校准补偿方法，还提出利用单矢量传感器速度协方差矩阵分解来求解目标源方位，使得我们不要求校准源是合作性的，也无需知道校准源的先验知识，这比起常规辅助源校准方法具备较大宽容性。随着高性能阵列处理技术及数字信号处理硬件的快速发展和矢量传感器制造工艺的不断成熟，矢量传感器将在新型水雷、低频远程智能鱼雷、声纳浮标、低频拖曳线列阵和新型舰壳声纳，灵巧传感终端，战场监视系统，反隐形雷达，通讯等军民用领域取得良好的发展应用前景。

The sine and cosine signals induced on stator are amplified by instrumentation amplifier and connected to the converter AD2S83, which is designed according to tracking goniometry. Digital logic control and address encoding are processed by FPGA, and the converted 16-bit parallel angle data and direction signal are transferred to DSP.

本设计中通过RC 振荡电路为感应同步器转子提供单相激磁信号，定子上感应出来的正弦和余弦两路信号通过仪表放大器的差分放大之后提供给基于跟踪型测角原理的转换芯片AD2S83，通过FPGA 实现数字逻辑控制以及地址解码，将转换后的16 位并行转角数据以及方向信号送入DSP 中。

In this design, a single-phase exciting signal generated by RC oscillatory circuit is applied to the rotor of synchro. The sine and cosine signals induced on stator are amplified by instrumentation amplifier and connected to the converter AD2S83, which is designed according to tracking goniometry. Digital logic control and address encoding are processed by FPGA, and the converted 16-bit parallel angle data and direction signal are transferred to DSP.

本设计中通过RC振荡电路为感应同步器转子提供单相激磁信号，定子上感应出来的正弦和余弦两路信号通过仪表放大器的差分放大之后提供给基于跟踪型测角原理的转换芯片AD2S83，通过FPGA实现数字逻辑控制以及地址解码，将转换后的16位并行转角数据以及方向信号送入DSP中。

In this design, a single-phase exciting signal gener AT ed by RC oscill AT ory circuit is applied to the rotor of synchro. The sine and cosine signals induced on st AT or are amplified by instrument AT ion amplifier and connected to the converter AD2S83, which is designed according to tracking goniometry. Digital logic control and address encoding are processed by FPGA , and the converted 16-bit parallel angle d AT a and direction signal are transferred to DSP.

本设计中通过RC振荡电路为感应同步器转子提供单相激磁信号，定子上感应出来的正弦和余弦两路信号通过仪表放大器的差分放大之后提供给基于跟踪型测角原理的转换芯片AD2S83，通过 FPGA 实现数字逻辑控制以及地址解码，将转换后的16位并行转角数据以及方向信号送入DSP中。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。