查询词典 Doppler range

A new approach to eliminate the ranges dependence based on angular frequency shifting in space domain was presented, in which, the nonhomogeneity of clutter is removed and the blind area of target detection is reduced due to the fact that the clutter of all the compensated range cells in every channel is moved to the place of the clutter of the desired cell by the different angular frequency shifts being added into spatial data along all Doppler channels for every compensating range cell.

第七章针对非正侧视相控阵机载雷达，由于杂波在距离上呈现出严重的非均匀性，尤其是在近程这种依赖距离的杂波谱呈现的非均匀现象更为严重，使得用于计算自适应权的协方差矩阵不可能直接由距离单元数据统计平均来估计得到，否则STAP处理及其降维技术难以获得理想的杂波抑制性能和目标检测性能，甚至恶化。

The key problems of software radio and direct sequence spread spectrum range used in high range radio fuze are discussed. The effects of doppler frequency and carrier's initial random phase are analyzed. A new direct sequence spread spectrum algorithm based on software radio is proposed, by using differential encoding and quadrature demodulating, the effects of doppler frequency and carrier's initial phase on the output of inference filter are eliminated successfully.

研究了软件无线电和直接扩频测距技术在大炸高无线电引信应用中的关键技术问题，分析了由于多普勒效应引起的载波频偏以及载波随机相位对测距的影响，提出了一种基于软件无线电的直接序列扩频解调算法，通过采用差分编码和正交解调的方法，消除了多普勒频偏和载波随机相位对测距的影响。

The study indicates that the influence of Doppler effect on pseudo-range observations is proportional to the product of pseudo range and the rate of pseudo-range variation.

研究表明，多普勒效应对伪距观测值的影响与伪距和伪距变化率的积成正比。

The main contents is: analyzing some detection method to moving target nowadays; particular studying the principle of detection moving target in SAR; analyzing SAR imaging theory and the echo model of moving target; discussing conventional SAR imaging , the movements of target cause the changes of doppler mass center and regulable frequency, and the changes cause effect the imaging result; introducing the estimation method of doppler parameter; analyzing theory of DPCA, derivating the formula needed, and validating it's validity and practicability through simulation; advancing the improved DPCA algorithm that combine the advantage of DPCA and ATI, and validating it through computer simulation; using the revision algorithm to range ambulate based on keystone transformation, and validating it through computer simulation; discussing the compensation art of SAR imaging.

主要内容有：分析了现有的一些动目标的检测方法；详细研究了SAR动目标检测的原理；分析了SAR成像理论和运动目标的回波模型；探讨常规SAR成像时，目标运动引起的多普勒质心和调频率变化，以及这些变化对成像结果的影响；介绍了多普勒参数的估计方法；分析了DPCA原理，推导所需要的基本公式，并仿真验证其有效性和实用性；提出了结合DPCA和ATI优点的改进DPCA算法，并仿真验证；探讨了SAR成像中的运动补偿技术。通过对仿真结果的分析，本文提出的方法具有一定的指导意义和参考价值。

The main work of this dissertation focuses on two aspects. The first,, the existing problems, such as range alignment and scatterer Migration Through Resolution Cell , in real data processing, are discussed and the corresponding algorithms are proposed to deal with the problems; Second, the real time imaging for maneuvering targets is carried out and a simple Range-Instantaneous Doppler algorithm is developed.

为此，本文的主要工作一方面对实测数据中存在的问题如包络对齐、散射点越距离单元走动的问题进行了进一步研究，提出了一些较为有效的算法；另一方面，在ISAR实用化方面进行了一定的研究，提出了一种ISAR机动目标实时成像的简化算法。

In this paper, an algorithm to achieve both two dimensional high resolution and wide swath is proposed. Every small satellite work in the active state, they transmit and receive different frequency band signal simultaneity. First, the azimuth ambiguity is eliminated in each frequency sub-band, then the signal is rectified to zero Doppler frequency, after that this algorithm does the range spectral synthesis to achieve high range resolution.

该文分析了一种沿航向排列分布式小卫星宽测绘带二维高分辨率成像技术，每颗卫星同时发射接收不同频率的线性调频信号，先分别在每个子带解方位多普勒模糊，并将方位多普勒中心频率调整至零频，然后在距离向进行子带拼接得到大带宽的线性调频信号从而得到高的距离向分辨率。

The quantity computed is the expected clutter power at the output of any specified range gate by the method of integrating reflected energy between constant Doppler loci in range-gate circles with a model of sum and difference antenna gain pattern for APAR. Base on the analyzing of APAR terrain clutter spectrum, Rayleigh, Correlated Log-Normal and Weibull distribution terrain clutter of APAR general pulse signal was simulated with the method of zero memory nolinearity transform.④The Doppler frequency of target echo is simulated on video frequency in this dissertation.

该软件采用了用C语言建立框架结构，而在程序高重复部分和有运算速度要求的地方，用汇编语言编写具有高并行能力程序的方法，不仅满足了系统高运算速度和实时性的要求，也使得软件系统结构模块化，代码具有良好的维护性和重用性；③对机载相控阵雷达HPRF、MPRF的和、差通道地面杂波功率谱进行了较为全面的研究，通过建立由四个子波束构成的机载相控阵雷达杂波和差波束天线方向图数学模型，选取体现高度线杂波的修正的地面后向散射模型，以载机平飞为例，采用沿距离门——等多普勒线区域积分的方法，得到了杂波功率谱，并利用零记忆非线性变换法实现了机载相控阵雷达常规脉冲情况下瑞利分布、对数正态分布和韦布尔分布地面杂波的模拟；④提出了采用在视频上对目标回波的多普勒频率进行模拟的方法。

Based on the analysis of bistatic SAR geometry model, bistatic SAR echoed signal is modeled in the double range variables domain in this paper, and the relationship between the double range variable domain and the single range variable domain is established. Then a range-dependent Doppler algorithm for imaging processing airborne bistatic SAR raw data of the translationally invariant configuration is derived, and the effect of error of the algorithm is analyzed by simulating.

摘要该文通过对机载双基地SAR非移变几何模型的分析，建立了双距离变量域的回波信号模型，由于回波数据是在距离和域，该文推导了距离和变量与双距离变量的转换关系，解决了该模型向距离和变量域转换的问题；提出了适用于非移变模式的变多普勒参数的双基地RD算法，并对该算法中引入变多普勒斜率所存在的误差进行了仿真分析。

The Doppler frequency shift and the Doppler broadening are comprehensively utilized, the narrow-band phase plate is inserted between a collimating mirror and a focusing lens of an imaging probe, thereby implementing the spatial encoding of the Doppler information, realizing the imaging requirements on the spatial high-resolution three-dimensional speed vector, combining with the Doppler OCT method which is based on the phase resolution technology to meet the high-speed and high-sensitivity measurement requirements and finally realizing the speed vector imaging with high-resolution, high-speed, high-sensitivity and large-imaging range of the three-dimensional flow field of the microfluidic chip.

综合利用多普勒频移和多普勒展宽，并在成像探头的准直镜和聚焦透镜之间插入窄带相位片，实施多普勒信息的空间编码，实现空间高分辨三维速度矢量的成像要求，再结合基于相位分辨技术的多普勒OCT方法则能够满足高速度高灵敏度的测量要求，最终实现对微流控芯片立体流场的高分辨率、高速度、高灵敏度、大成像范围的速度矢量成像。

Because the scatterers at different range cells may have different Doppler characteristics, the range migration correction for moving ship is completed by coarse and fine correction procedures. The compensations of second and higher order phase terms are implemented in "range frequency - azimuth time" domain.

根据船体上不同距离单元散射点多普勒历程可能不同的特点，采用粗校正和精校正相结合的方法在距离频率-方位时间域进行二阶和高阶相位补偿，完成运动舰船目标的距离徙动校正。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。