针对传统液位测量系统精度低、抗干扰能力差、接触式的特点,介绍一种利用雷达原理研制的数字式液位测量系统。本系统采用调频测量法,用C8051F020单片机作为频率测量模块的核心。运用自相关函数对信号进行滤波 快速傅里叶变换(FFT)算法进行频域分析 移频法对频率进行细化,最后得到液位的高度。该系统具有很强的适应能力和完善的接口,在实测中取得了满意的精度。 -Traditional level measurement system accuracy, anti-jamming capability,

基于MATLAB平台的PWM调制正弦波的快速傅里叶分析-his model simulates and computes Fourier analysis of PWM based sinusoidal waveform. Fundamental frequency can be changed in model properties. Amplitude modulation index and frequency modulation index can be adjusted in Sim

掌握离散傅立叶级数及快速傅里叶变换,掌握离散时间傅立叶变换并分析其周期性和对称性-Fu Liye master discrete Fu Liye series and fast Fu Liye transform, master discrete time Fu Liye transform and analysis of its periodicity and symmetry transform and spectrum analysis