SUBROUTINE PARSVL (DATA, NP.INP, AVE, ANOIS,NWGT,ANORM) 

 C ROUTINE TO COMPUTE THE AVE VALUE OF THE LAST 10 PERCENT OF THE 

 C HARMONICS (AVE) OF AN AMPLITUDE SPECTRUM(DATA) AND USE THIS VALUE WITH 

 C PARSE VALS FORMULA TO COMPUTE THE RMS WHITE NOISE LEVEL (ANO IS ) . 

 C** NP=THE NO. OF ORIGINAL PTS INPUT TO THE FFT USED TO COMPUTE DATA ARRAY 

 C** INP=THE NO. OF POINTS TO A POWER OF 2 USED FOR THE FFT 

 C** DATA= UNNORMALIZED FFT AMPLITUDE SPECTRUM WITH UNITS OF 

 C** INPUT UN ITS /CYCLE /DATA INTERVAL AND IS OF LENGTH ( INP/2)+l-2*NWGT 

 C** NWGT=LENGTH OF SMOOTHING FILTER YOU USED ON YOUR FFT -NWGT. .0. .+NWGT 



DIMENSION DATA(l) 



IF(ANORM.EQ.l.) GO TO 11 



DO 10 I=1,NP 



10 DATA(I)=DATA(I)/ANORM 



11 JX=INP/2+l-2*NWGT 

 JT=JX-(JX/10) 

 X=0.2*INP 

 JX=X-2.0 

 T=0.13*INP 

 JT=T-2.0 

 DIF=JX-JT+1 

 ANP=NP 



AVE =0.0 

 AVEPS=0.0 

 DO 1 I=JT,JX 

 AVE=AVE+DATA(I) 

 1 AVEPS=AVEPS+DATA(I)**2 

 AVE=AVE/DIF 

 AVEPS=AVEPS/DIF 

 C PARSEVALS FORMULA IS MEAN SQ NOISE=(INP*AVEPS )/(NP*INP) 

 ANOIS=SQRT(AVEPS/ANP) 

 IF(ANORM.EQ.l.) RETURN 

 00 12 1=1, NP 



12 DATA(I)=DATA(I)*ANORM 

 RETURN 



END 



200 



