| 摘要 |
<p>PURPOSE:To enable determination of Fourier transformed value in a short time after scanning by obtaining Fourier transformed data by scanning for two axes intersecting at right angles and making Fourier transformation for data parallel with scanning. CONSTITUTION:In the case where number of measured data NXM=4X4, (a) e0<-x> is obtained by scanning for Y direction m=O, and Fourier transformation in X direction is performed. This is written in an auxiliary memory as D<-x>0. (b) making Y direction m=1, and operation similar to (a) is performed for e<-x>1. (C) The first step calculation of FFT is made according to algorithm of high speed Fourier transformation FFT for D<-x>0, D<-x>1, and this is written in the auxiliary memory. (d) Operation similar to (a) is performed for Y direction m=2. (e) Operation similar to (a) is made for Y direction m=3 (scanning is completed). Remaining step of FFT is performed according to algorithm of FFT. Thus, Fourier transformed value is obtained in a short time after scanning.</p> |
