1) Doppler frequency
多普勒频率
1.
Based on traditional techniques of passive location,single-station passive location is achieved by adding observation information,which is bearing and Doppler frequency joint location method.
在传统的无源定位技术基础之上,采用增加观测信息量的方法来实现单站无源定位,即方位/多普勒频率联合定位技术。
2.
When detecting the high-speed moving target by using phase-coded signals,Doppler frequency compensation is necessary because of the Doppler frequency sensitivity of phase-coded signals.
利用相位编码信号探测高速运动目标时,存在多普勒频率敏感性问题,需要对多普勒频率进行补偿。
3.
Amplitude distortion and phase distortion of signal caused by radar transmitter and receiver and Doppler frequency produced by target radical movement are three key factors that influence the performance of pulse compression.
由雷达发射、接收系统导致的信号幅度、相位失真以及由目标径向速度导致的目标多普勒频率是影响脉冲压缩性能的三个主要因素。
2) doppler rate
多普勒调频斜率
1.
Errors caused by the aircraft motion and orientation lead to the errors of the Doppler centroid and Doppler rate,thus some significant distortions appear in images.
针对真实飞行条件下飞机运动和定位误差导致多普勒中心频率和多普勒调频斜率误差,从而使图像出现大的变形的特点,提出了真实飞行条件下估计接收数据多普勒中心频率和多普勒调频斜率的新方法。
2.
A new method for estimating the Doppler rate in synthetic aperture radar (SAR) imaging is presented based on the four-parameter Chirplet decomposition of the signal in a range bin.
提出了基于一个距离门信号的四参数 Chirplet分解方法 ,估计合成孔径雷达 ( SAR)回波的多普勒调频斜率。
3.
This paper analyzes the relation between the Doppler rate and phase gradient,and proposes algorithm for the Doppler rate estimation with the PGA,then the performance of this algorithm is verified by the computer simulation data and airborne SAR data.
本文详细地分析了多普勒调频斜率误差与相位梯度的关系 ,提出了基于PGA的多普勒调频斜率估计算法 ,并进行了仿真和机载SAR数据的成像实验 。
3) Doppler centroid
多普勒中心频率
1.
Errors caused by the aircraft motion and orientation lead to the errors of the Doppler centroid and Doppler rate,thus some significant distortions appear in images.
针对真实飞行条件下飞机运动和定位误差导致多普勒中心频率和多普勒调频斜率误差,从而使图像出现大的变形的特点,提出了真实飞行条件下估计接收数据多普勒中心频率和多普勒调频斜率的新方法。
2.
A complex sign Doppler estimator (CSDE) is proposed for real-time hardware-based synthetic aperture radar (SAR) Doppler centroid estimation.
针对可编程器件实现合成孔径雷达多普勒中心频率实时估计问题,提出了复符号估计算法·新算法利用合成孔径雷达回波先验零均值圆对称复高斯分布统计特性,运用复反正弦定律非线性估计回波相关值,降低了多普勒中心频率估计复杂度,适合硬件实现·分析和仿真结果表明,与已有的符号多普勒中心频率估计算法相比,复符号多普勒中心频率估计算法不但大大降低了运算量和相应硬件的实现面积,提高了整个多普勒中心频率估计运算部件的运行效率,而且具有与其相当的估计性能
3.
This paper estimates Doppler centroid using the averaged azimuth spectrum, and it estimates the Doppler frequency rate by computing the shift between subimages.
根据平均后的方位谱来估计多普勒中心频率,通过计算子图像之间的位移值来估计多普勒调频斜率。
4) Doppler central frequency
多普勒中心频率
1.
This paper analyzed the Doppler central frequency,fDCand the Doppler central frequency difference Δ fDC which are two important parameters for the system and gives along-track baseline control requirement.
针对分布式SAR卫星对偏航控制和波束同步要求的特点,文章对其两个重要参数多普勒中心频率fDC和多普勒中心频率差ΔfDC进行了详细分析,提出了沿迹基线的要求。
2.
Base on different sources of noise in interferogram, we analysed the reasons why the master and slave images Doppler central frequency was inconsistent under the repeat-track interferometry and its influence to interferogram.
根据干涉图中噪声的不同来源,重点分析了在重复轨道干涉测量模式下,主辅影像多普勒中心频率不一致的成因及其对干涉图的影响。
5) Doppler frequency signal
多普勒频率信号
6) doppler frequency rate
多普勒调频率
1.
The Estimation of spaceborne SAR Doppler frequency rate is studied.
估计星载合成孔径雷达 ( SAR)的多普勒调频率 ,建立星载 SAR方位向信号相位的多项式模型 。
2.
This paper discusses the effects on spaceborne synthetic aperture radar(SAR) imaging quality resulting from errors in the Doppler parameters used in imaging processing,and proposes a new method called Autofocus estimation method to estimate Doppler centroid and Doppler frequency rate with the cross-correlations of the first-look and the fourth-look subimag- ings in range and azimuth respectively.
主要分析了星载合成孔径雷达(SAR)多普勒参数的估计误差对成像质量的影响,提出了利用自聚焦同时估计多普勒质心和多普勒调频率的方法;该方法使得两个多普勒参数的估计在准均匀和非均匀场景下能同时具有较高的精度,而且使估计的运算量也大为减少;最后通过星载 SEASAT-A海洋卫星原始数据成像试验,证明了该方法的优越性。
3.
In airborne synthetic aperture radar, accuracy of the Doppler frequency rate affects the image quality directly.
在传统单站机载合成孔径雷达(SAR)中,多普勒调频率的估计精度直接影响着成像的质量。
补充资料:彩色多普勒血流成像
彩色多普勒血流成像
超声学检查方法之一。又称“彩色多普勒血流图”。应用脉冲超声多普勒原理,在二维和M型超声心动图基础上,用彩色实时显示血流的方向和相对速度,提供心脏和大血管内血流的时间和空间信息的超声诊断技术,是80年代多普勒超声心动图的重要进展。人体和血流的反射信号经结构分析和血流分析处理后,可在显示屏上显现的黑白实时二维声像图上叠加彩色实时血流影像。还可与M型超声心动图、脉冲波和连续波声谱图显示同时进行。其特点是可同时显示心腔某一断面上全部异常血流束的分布及数目;表现血流途径及方向,辨别层流、湍流和涡流;测量血流束的面积、长度、宽度;显示结构异常与血液动力学异常的关系。临床应用于心脏瓣膜病、先天性心脏病、心肌病及心脏肿瘤等无创性诊断,提高了诊断的敏感度和准确度。此技术方法尚有混叠现象及显示帧数受限的缺点。
说明:补充资料仅用于学习参考,请勿用于其它任何用途。
参考词条