SUGOUPILLAUDPO - calculate Primaries-Only impulse response of a lossless   
              GOUPILLAUD medium for plane waves at normal incidence         

 sugoupillaudpo < stdin > stdout [optional parameters]                      

 Required parameters:							     
        none                                                                

 Optional parameters:                                                       
        l=1           source layer number; 1 <= l <= tr.ns                  
                      Source is located at the top of layer l.	             
        k=1           receiver layer number; 1 <= k                         
                      Receiver is located at the top of layer k.            
        tmax          number of output time-samples;                        
                      default: long enough to capture all primaries         
        pV=1          flag for vector field seismogram                      
                      (displacement, velocity, acceleration);               
                      =-1 for pressure seismogram.                          
        verbose=0     silent operation, =1 list warnings                    

 Input: Reflection coefficient series:                                      

		               impedance[i]-impedance[i+1]                   
		       r[i] = -----------------------------                  
		               impedance[i]+impedance[i+1]                   

        r[0]= surface refl. coef. (as seen from above)                      
        r[n]= refl. coef. of the deepest interface                          

 Input file is to be in SU format, i.e., binary floats with a SU header.    

 Remarks:                                                                   
 1. For vector fields, a buried source produces a spike of amplitude 1      
 propagating downwards and a spike of amplitude -1 propagating upwards.     
 A buried pressure source produces spikes of amplitude 1 both in the up-    
 and downward directions.                                                   
    A surface source induces only a downgoing spike of amplitude 1 at the   
 top of the first layer (both for vector and pressure fields).              
 2. The sampling interval dt in the header of the input reflectivity file   
 is interpreted as a two-way traveltime thicknes of the layers. The sampling
 interval of the output seismogram is the same as that of the input file.   

 
 Credits:
	CWP: Albena Mateeva, April 2001.