pevModelLambdaRange

range of lambda values for position-error velocity model

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Declaration

 [minLambda,maxLambda] = pevModelLambdaRange(x, X, VV, distribution)

Parameters

• x the observations (Nx1)
• X splines on the observation grid, NxM
• VV velocity penalty matrix, MxM
• distribution distribution describing the errors

Returns

• minLambda minimum value of lambda that could affect the solution
• midLambda mid value of lambda that could affect the solution
• maxLambda maximum value of lambda that could affect the solution

Discussion

Estimate the minimum and maximum values of lambda that should be considered, given the balance between the position-errors and the velocity model. lambda can always be safely set to zero, but the minimum value is still useful for a logarithmic search algorithm. If the rank of (VV) is less than N, then the solution may not be invertible if lambda is too large. The maxLambda value should prevent this.