对于超宽带LFM信号目标探测系统,存在距离-多普勒耦合、多普勒色散,影响目标速度的测量.为此该文采用了用于波达方向(direction of arrival,DOA)高分辨估计的投影子空间正交测试(test of orthogonality of projected subspaces,TOPS)法...对于超宽带LFM信号目标探测系统,存在距离-多普勒耦合、多普勒色散,影响目标速度的测量.为此该文采用了用于波达方向(direction of arrival,DOA)高分辨估计的投影子空间正交测试(test of orthogonality of projected subspaces,TOPS)法来估计目标径向速度.算法首先根据雷达中目标速度和均匀线阵(uniform linear array,ULA)中空间频率间存在的同构关系,基于TOPS算法,对LFM UWB雷达目标进行高分辨速度估计,然后利用速度值对回波进行相应补偿后获得目标的高分辨距离像.该文还推导了目标速度的适应性区域,并通过仿真实验结果说明该文所提方法可以有效解决超宽带雷达多普勒色散对目标测速造成的影响.展开更多
Based on real-time digital simulations(RTDS),a laboratory environment similar to the real-time operation situation of the Three Gorges Hydropower Station is established.Then,the causes for the power fluctuation of the...Based on real-time digital simulations(RTDS),a laboratory environment similar to the real-time operation situation of the Three Gorges Hydropower Station is established.Then,the causes for the power fluctuation of the second generator by errors in the rotor rotating speed calculation are found,and the tuning method of the speed related parameters are given.The damping and reverse tuning characteristics of power system stabilizers(PSSs)in the digital automatic voltage regulator(AVR)are compared and investigated in the frequency range of 0.18-1.1 Hz.The efficiency of the proposed tuning method for ensuring power system stability is verified by RTDS.Finally,field tests show the validity of the laboratory test results.展开更多
A method, called class multiple signal classification （CMUSIC）, is proposed to estimate high-resolution radial velocity in each pulse train （subband, i.e. narrowband） with M pulses based on stepped frequency pulse...A method, called class multiple signal classification （CMUSIC）, is proposed to estimate high-resolution radial velocity in each pulse train （subband, i.e. narrowband） with M pulses based on stepped frequency pulse trains （SFPTs） signal. A synthetic ultra-wideband （UWB） high-resolution range profile （HRRP） is then obtained by fast Fourier transform （FFT） processing along the subbands after compensating the range-Doppler coupling and Doppler dispersion with the estimated velocity. Compared with the other methods, CMUSIC has fine performance of velocity estimation at low signal-to-noise ratio （SNR） level. This method also has excellent performance with small Mas long as the requirement, i.e. Mis large than Q, is able to be fulfilled, where Q is the number of targets with different radial velocities. In addition, through a radial velocity resolving, the method can be well suitable for targets moving at high radial velocities, which has significant practical value with considerable progress made in the national defence technology and the advanced vehicles moving at high speed springing up. Simulation results demonstrate the feasibility and effectiveness of the method.展开更多
文摘对于超宽带LFM信号目标探测系统,存在距离-多普勒耦合、多普勒色散,影响目标速度的测量.为此该文采用了用于波达方向(direction of arrival,DOA)高分辨估计的投影子空间正交测试(test of orthogonality of projected subspaces,TOPS)法来估计目标径向速度.算法首先根据雷达中目标速度和均匀线阵(uniform linear array,ULA)中空间频率间存在的同构关系,基于TOPS算法,对LFM UWB雷达目标进行高分辨速度估计,然后利用速度值对回波进行相应补偿后获得目标的高分辨距离像.该文还推导了目标速度的适应性区域,并通过仿真实验结果说明该文所提方法可以有效解决超宽带雷达多普勒色散对目标测速造成的影响.
文摘Based on real-time digital simulations(RTDS),a laboratory environment similar to the real-time operation situation of the Three Gorges Hydropower Station is established.Then,the causes for the power fluctuation of the second generator by errors in the rotor rotating speed calculation are found,and the tuning method of the speed related parameters are given.The damping and reverse tuning characteristics of power system stabilizers(PSSs)in the digital automatic voltage regulator(AVR)are compared and investigated in the frequency range of 0.18-1.1 Hz.The efficiency of the proposed tuning method for ensuring power system stability is verified by RTDS.Finally,field tests show the validity of the laboratory test results.
文摘A method, called class multiple signal classification （CMUSIC）, is proposed to estimate high-resolution radial velocity in each pulse train （subband, i.e. narrowband） with M pulses based on stepped frequency pulse trains （SFPTs） signal. A synthetic ultra-wideband （UWB） high-resolution range profile （HRRP） is then obtained by fast Fourier transform （FFT） processing along the subbands after compensating the range-Doppler coupling and Doppler dispersion with the estimated velocity. Compared with the other methods, CMUSIC has fine performance of velocity estimation at low signal-to-noise ratio （SNR） level. This method also has excellent performance with small Mas long as the requirement, i.e. Mis large than Q, is able to be fulfilled, where Q is the number of targets with different radial velocities. In addition, through a radial velocity resolving, the method can be well suitable for targets moving at high radial velocities, which has significant practical value with considerable progress made in the national defence technology and the advanced vehicles moving at high speed springing up. Simulation results demonstrate the feasibility and effectiveness of the method.
