雷达液位测量的精度分析及ZoomFFT算法的实现

Radar level measurement accuracy analysis and ZoomFFT algorithm implementation

文中首先介绍了线性调频连续波雷达(LFMCW)液位测量系统的基本原理,然后阐述了液位测量的精度及影响因素,接着给出了频率估计的方差Cramer-Rao下限。为了提高测量精度及分辨率,需对FFT运算完的频谱进行细化分析。常见的方法有Chirp-z变换、复调制ZoomFFT法等,本文给出了基于复解析带通滤波器的ZoomFFT算法的分析过程,同时通过计算机用matlab仿真该算法,并在数字信号处理芯片上实现其在液位测量实际情况中的应用,本方法计算效率优越、分辨率高。

This paper introduces a Linear Frequency Modulated Continuous Wave Radar （LFMCW） the basic principles of level measurement system, and then describes the level measurement accuracy and influencing factors, and then given frequency estimation variance Cramer-Rao lower limit. In order to improve the measurement accuracy and resolution, the need for spectrum FFT operation after detailed analysis. Common method Chirp-Z transform complex modulation ZoomFFT of law, this paper presents analysis based the complex analytic bandpass filter ZoomFFl＂ algorithm matlab simulation algorithm, at the same time through a computer, and digital signal processing chip the actual situation of the level measurement applications, the superior computational efficiency, high resolution.