3D Electromagnetic inversion using conjugate gradients

Conference · Sun Jun 01 00:00:00 EDT 1997

OSTI ID:501488

Newman, G A; Alumbaugh, D L

In large scale 3D EM inverse problems it may not be possible to directly invert a full least-squares system matrix involving model sensitivity elements. Thus iterative methods must be employed. For the inverse problem, we favor either a linear or non-linear (NL) CG scheme, depending on the application. In a NL CG scheme, the gradient of the objective function is required at each relaxation step along with a univariate line search needed to determine the optimum model update. Solution examples based on both approaches will be presented.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 501488
• Report Number(s): SAND--97-1296C; CONF-970847--2; ON: DE97006369
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
66 PHYSICS
99 GENERAL AND MISCELLANEOUS
CONVERGENCE
ELECTROMAGNETIC RADIATION
GEOPHYSICS
IMAGE PROCESSING
INVERSE SCATTERING PROBLEM
ITERATIVE METHODS
LEAST SQUARE FIT
MATRIX ELEMENTS
THREE-DIMENSIONAL CALCULATIONS