三维功率谱阵及其应用

The Waterfall Spectrum and Its Application

三维功率谱阵是应用越来越广泛的信号处理方法。快速高精度的FFT 和谱分析;准确而适用范围广的转速测量方法;高精度时钟系统和灵活方便.功能齐全的显示技术是其要解决的四个难点。本文从采用汇编语言、窗函数库和三角函数库、双段2048点实数一次完成FFT 运算、加校正因子和幅值修正等方面论述了提高软件实现FFT 和谱分析速度和精度的方法;首次提出了用计算机内部8253计数器进行精确测量时间的方法,并由此实现了适用范围广、误差小于1%的转速测量;采用的三维谱阵显示方法具有独特的光标显示功能。以上述方法为基础的三维功率谱,其性能指标达到了较高的水平。

The waterfall spectrum is one of the important signal processing methods which are widely used.Anefficient waterfall specturm technique relies on the following four key items:high speed and high-accuracyFFT and spectrum analysis technique;accruate RPM measuring algorithm;high-accurate calculation timeand full-functional spectrum display which is easy to use.This paper presents some techniques such as as-sembly language,window function library,trigonometric function library,real FFT of two segments and2048 points,rectification coefficient and amplitude modification etc,which can effectively improve thespeed and accuracy of FFT and spectrum analysis.By means of the internal 8253 counter in the computerto accurately measure time,a high RPM measurement accuracy of 1% may he got.Furthermore a new wa-terfall spectrum display with cursor is introduced in this paper.Based on the above methods,a waterfallspectrum program of high performance is developed.