多普勒频率

• The four - parameter basis functions decomposition of time - frequency signal representation is presented based on the characteristics of doppler frequency of the radar echoes , thereby dopplerlet transform is introduced
  根据接收到的雷达目标回波信号的多普勒频率特性，提出用4参数基函数的时频信号表示法，从而引出多普勒小波变换的概念。
• On the other hand , the irls algorithm is employed to design mismatched filters for other signals , such as linear frequency modulated chirp . the methods of improving tolerance of low doppler shifts are given finally
  同时我们还将迭代加权最小二乘算法推广应用于其它信号形式的脉冲压缩滤波器设计，并提出了有关多普勒频率性能的改善方法。
• In the traditional polarization diversity and combining scheme , differential mode loop and common mode loop is combined to lock in the phase and frequency of the diversity signals and remove the carrier frequency bias and doppler shift
  传统的极化分集接收方案是将差模环和共模环相结合完成两路信号的同频同相锁定以及多普勒频率偏移的去除。
• Because of the presence of the first - order sea echoes with dominant amplitude , the doppler resolution technique which based on the range - velocity transformation is needed to extract the targets information in hf radar
  高频雷达工作在拥挤的短波波段,由于绝对占优的一阶海浪回波的存在,必须采用基于距离?速度谱变换的多普勒频率分辨技术来处理杂波,以提取目标信息。
• The fruits of emulational research are obtained : 1 the method of divided planar correlation deal with wonderfully and can detect the target information of tv sound fm signal about time difference and doppler frequency with this understanding of - 20db snr
  仿真研究成果： 1 、分段二维相关处理方法效果不错，能在- 20db信噪比情况下，可靠地检测到电视伴音调频目标信号的时差与多普勒频率信息。
• Motion errors are given first , and then theoretical analysis , simulation result show affections caused by 3 kinds of typical motion errors both on the doppler and the image . last the phase error criterions are given . 4
  4 .研究了机载双站sar中偏航、俯仰和横滚三种姿态误差对回波多普勒频率和雷达成像的影响,并分析研究了天线指向误差对回波幅度的影响,最后通过仿真实验证明了研究的正确性。
• Sthe azimuth resolution characteristics for different deployments of the antennae ’ irradiation mode is discussed clearly through analyzing the doppler history of the echoed signal based on the platforms " motion features and antennae " irradiation rules
  根据收、发载机平台的运动特点和天线波束在观测场景平面内的照射规律,本文采用多普勒频率分析的方法详细讨论了发射、接收天线采用不同照射配置方式时系统的方位向分辨特性。
• Attitude errors are given first , and then theoretical analysis , simulation result show 3 kinds of attitude errors ’ affection both on the doppler and the image . 5 . motion compensations based on gps / ins / imu control system and pga self - focus arithmetic are analyzed
  5 .研究了以gps / ins / imu为基础的平台控制系统和以pga算法为基础的自聚焦两种主要的运动补偿方案,并根据载机运动状态和多普勒频率的关系,推导了一种基于瞬时运动状态的运动方法,最后结合rd算法加以补偿。
• Backed up by the soplat theory based on particle kinematics , the second chapter of this paper presents with analysis and simulation of several single observer passive measurement models , which uses such relative movement parameters as bearings changing rates and centrifugal acceleration information on the basis of bearings measurements . in the third chapter , the observability of location respectively using bearings and its changing rates information and centrifugal acceleration information is analyzed , and its observable condition is got . the fourth chapter puts forward the modified covariance extended kalman filtering ( mvekf ) against the defect of traditional extended kalman filtering ( ekf ) , whose performance is simultaneously compared in the chapter with the performance of ususal tracking algorithm such as ekf , mgekf , iekf by computer simulation
  在近年来提出的基于质点运动学原理的单站无源定位理论基础上，本文第二章提出了几种在角度测量的基础上增加角度变化率及相对运动的离心加速度等运动学参数的单站无源测量模型，并对它们进行了分析和仿真；第三章分别对利用角度及其变化率信息定位和利用离心加速度信息定位的可观测性进行分析并得到了相应的可观测条件；第四章针对传统扩展卡尔曼( ekf )方法的缺点，提出了一种修正协方差的扩展卡尔曼滤波( mvefk )方法，并将其和ekf 、 mgekf 、 iekf等常用的单站无源定位滤波方法进行了性能仿真比较；第五章通过引入雷达机动目标跟踪方法和模型，提出了利用角度及其变化率对机动辐射源跟踪的多级噪声自适应方法和imm方法；第六章主要对角度变化率和离心加速度参数的获取技术进行了研究，提出了几种高精度测量脉冲序列多普勒频率变化率的方法。
• Based on the configure of direction finding , the location method , algorithm , accuracy and performance for multistations and single station are studied in this thesis , and the computer simulation results are given out . it is important of resolving the performance of antenna array . a technique to estimate and calibrate the performance is developed in this page
  本文以测向系统的组成为基础，研究了单平台情况下利用到达方向、到达时间差、多普勒频率差、相位变化率等参数的测向方法、测向算法、测向精度和性能，并进行了计算机仿真，为无源测向系统的设计和实施提供了重要的理论基础和实验数据。