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This is equivalent to pre-multiplying **L** by the diagonal matrix and solving the system:

| |
(14) |

The data-space preconditioner can be interpreted as an approximation
to a ``data covariance'' operator that is used to express the reliability
and the correlation of the data measurements. In iteratively
re-weighted least squares, it approximates a data variance measure that
can be estimated from the current residual Nichols (1994).

** Next:** Model-space preconditioning
** Up:** Inversion to common offset
** Previous:** Diagonal weighting preconditioning
Stanford Exploration Project

7/5/1998