25 lines
		
	
	
		
			778 B
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			25 lines
		
	
	
		
			778 B
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| subroutine ana64(dd,npts,c0)
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| 
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|   use timer_module, only: timer
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| 
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|   parameter (NMAX=60*12000)                  !Max size of raw data at 12000 Hz
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|   parameter (NSPS=3456)                      !Samples per symbol at 6000 Hz
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|   parameter (NSPC=7*NSPS)                    !Samples per Costas array
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|   real dd(NMAX)                              !Raw data
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|   complex c0(0:720000)                       !Complex spectrum of dd()
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|   save
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| 
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|   nfft1=672000
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|   nfft2=nfft1/2
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|   df1=12000.0/nfft1
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|   fac=2.0/nfft1
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|   c0(0:npts-1)=fac*dd(1:npts)
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|   c0(npts:nfft1)=0.
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|   call four2a(c0,nfft1,1,-1,1)             !Forward c2c FFT
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|   c0(nfft2/2+1:nfft2)=0.
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|   c0(0)=0.5*c0(0)
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|   call four2a(c0,nfft2,1,1,1)              !Inverse c2c FFT; c0 is analytic sig
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| 
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|   return
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| end subroutine ana64
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