Patent ID: 11880011
Assignee: UNIVERSITY OF HOUSTON SYSTEM
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 4:
5. The method of claim 4, wherein the step of generating predicted surface waves for each receiver comprises using the following equation:, u
     surf
     pred
    
    (
    
     x
     ;
     ω
    
    )
   
   =
   
    
     1
     A
    
    ⁢
    
     
      ∑
      
       
        dx
        i
       
       =
       
        -
        L
       
      
      L
     
      
     
      
       a
       i
      
      ⁢
      
       u
       ⁡
       (
       
        
         x
         +
         
          dx
          i
         
        
        ;
        ω
       
       )
      
      ⁢
      
       exp
       [
       
        i
        ⁢
        ω
        ⁢
        
         
          dx
          i
         
         
          
           V
           ph
          
          (
          ω
          )
         
        
       
       ]
      
     
    
   
  
  ,
 

wherein usurfpred(x;ω) is the predicted surface wave at a receiver located at x in frequency ω domain,, A
   =
   
    
     ∑
     
      
       dx
       i
      
      =
      
       -
       L
      
     
     L
    
    
     a
     i
    
   
  
  ,
 

 wherein ai is a weighting factor and L is a local spatial window size around x,
u(x+dxi;ω) is a recorded seismic trace at location x+dxi including surface waves and body waves,, exp
  [
  
   i
   ⁢
   ω
   ⁢
   
    
     dx
     i
    
    
     
      V
      ph
     
     (
     ω
     )
    
   
  
  ]
 

 is a phase shift operator to correct for surface wave propagation effect, and
vph(ω) is estimated surface wave phase velocity generated using nonlinear signal comparison (NLSC).