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Solving the particular LSJIMP problem  

Now that we have derived appropriate imaging and amplitude correction operators, we are ready to translate the general LSJIMP modeling equation ([*]) to my particular implementation. The primary image, $\bold m_0$, is mapped into data space primary events by NMO, $\bold N_0$. Similarly, a given pegleg image, $\bold m_{i,k,m}$, is mapped into data space by sequentially applying the differential geometric spreading correction ($\bold G_{i,m}$), Snell resampling ($\bold S_{i,m}$), HEMNO ($\bold N_{i,k,m}$), and finally, a reflection coefficient ($\bold R_{i,k,m}$). Let us rewrite equation ([*]) accordingly:  
 \begin{displaymath}
\bold d_{\rm mod} = \bold N_0 \bold m_0
 + \sum_{i=1}^p \sum...
 ...m} \bold N_{i,k,m} \bold S_{i,m} \bold G_{i,m} \bold m_{i,k,m}.\end{displaymath} (28)
We see that in equation ([*]), the analog to $\bold L_{i,k,m}$ in equation ([*]) is $\bold R_{i,k,m} \bold N_{i,k,m} \bold S_{i,m} \bold G_{i,m}$.

The data residual weight in equation ([*]), $\bf W_d$, can often strongly influence the success of the inversion. Technically, $\bf W_d$ carries a heavy burden: it must decorrelate and balance the residual. However, I have found that a simpler form for $\bf W_d$ nontheless pays dividends. I set $\bf W_d$, which has the same dimension as a CMP gather, to zero where the data, $\bf d$, has an empty trace, and also above the onset of the seabed reflection.

 

 


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Next: 2-D Field Data Results Up: Particular Implementation of LSJIMP Previous: Velocity-Depth Ambiguity in the
Stanford Exploration Project
5/30/2004