sufxdecon.su.main

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 SUFXDECON - random noise attenuation by FX-DECONvolution              

 sufxdecon <stdin >stdout [...]	                                

 Required Parameters:							

 Optional Parameters:							
 taper=.1	length of taper                                         
 fmin=6.       minimum frequency to process in Hz  (accord to twlen)   
 fmax=.6/(2*dt)  maximum frequency to process in Hz                    
 twlen=entire trace  time window length (minimum .3 for lower freqs)   
 ntrw=10       number of traces in window                              
 ntrf=4        number of traces for filter (smaller than ntrw)         
 verbose=0	=1 for diagnostic print					
 tmpdir=	if non-empty, use the value as a directory path	prefix	
		for storing temporary files; else, if the CWP_TMPDIR	
		environment variable is set, use its value for the path;
		else use tmpfile()					

 Notes: Each trace is transformed to the frequency domain.             
        For each frequency, Wiener filtering, with unity prediction in 
        space, is used to predict the next sample.                     
        At the end of the process, data is mapped back to t-x domain.  ", 



 Credits:			

	CWP: Carlos E. Theodoro (10/07/97)

 References:      							
		Canales(1984):'Random noise reduction' 54th. SEGM	
		Gulunay(1986):'FXDECON and complex Wiener Predicition   
                             filter' 56th. SEGM	                
		Galbraith(1991):'Random noise attenuation by F-X        
                             prediction: a tutorial' 61th. SEGM	

 Algorithm:
	- read data
	- loop over time windows
		- select data
		- FFT (t -> f)
		- loop over space windows
			- select data
			- loop over frequencies
				- autocorelation
				- matrix problem
				- construct filter
				- filter data
			- loop along space window
				- FFT (f -> t)
				- reconstruct data
 	- output data

 Trace header fields accessed: ns, dt, d1
 Trace header fields modified: