Tomography and remote sensing inverse problems

Gennady A. Ryzhikov and Vladimir N. Troyan

Table of contents



Introduction


1.    Mathematical  topics of remote sensing inverse problems
1.1  Basic principles of functional analysis
1.2  Ill-posed problems
1.3  Some aspects of mathematical statistics


2.    Functional links between sounding signal fields and medium parameters
2.1  Seismology and seismics
2.2  Ocean acoustics
2.3  Electromagnetic waves in the Earth interior and ionosphere
2.4  Remote sensing of the atmosphere


3.    Ray theory of sounding signal propagation
3.1  Basic concepts of ray theory
3.2  Ray approximation for scalar wave equation
3.3  WKBJ-method for 1D Helmholtz equation
3.4  Ray theory for elastic wave propagation
3.5  Ray approximation for stratified media
3.6  Surface waves in  stratified media
3.7  Ray approximation for electromagnetic fields
3.8  Some aspects of the ray-tomography problem


4.    Construction and interpretation of tomography functionals
4.1  Construction of linear functionals for a data set.
4.2  Tomography functional
4.3  Some examples of construction and interpretation of tomography functionals
4.4  Ray tomography functionals in dynamic-kinematic interpretation of remote sensing data
4.5  Construction of In- and Out- fields in stratified reference medium


5.    Tomography interpretation of remote sensing problems
5.1  Some aspects of linear tomography
5.2  Generalized Radon inversion in diffraction tomography
5.3  Optimal algorithms in reconstructive tomography
5.4  Critical analysis of retrieval errors and the Bakus-Gilbert method
5.5  Back-projection in diffraction tomography
5.6  Regularization methods in 3D ray tomography


Appendix
References


 TOMOGRAPHY AND REMOTE SENSING INVERSE PROBLEMS
.
G.A.Ryzhikov and V.N.Troyan

The book describes the state of the art in remote sensing inverse problems and their interpretation  in terms of computerized tomography.
The introductory chapter formulates some basic principles of functional analysis, mathematical statistics and approaches to  solving the ill-posed problems. A special attention is paid to the presentation of different methods of regularization. On the basis of the model of the sounding signal propagation in an examined medium,  the notion  tomography functional is introduced. Tomography functional maps the field of the unknown medium parameters into the set of the experimental data.  Examples of  tomography functionals are constructed for the scalar wave equation, Lame equation, and for the transfer equation with isotropic scattering. The main impact of the tomography experiment is relevant to the overlapping of the tomography functional supports; that is in general  the information on a medium voxel is contained in the whole set of measurements. The diffraction tomography algorithms are formulated,  and it is  shown  how a backprojection procedure in the generalized Radon transformation relates to holography. The physical grounds are presented for  applying  the proper regularization method to solve tomography problems of the remote sensing. The optimal decision criterion is investigated and the physical interpretation of the tomography functionals is performed. Information/statistical characteristics of the recovery of the functional on  the medium parameter field are finally analyzed.

Mathematical Physics, Tomography, Geophysics

For researchers, students and engineers

219 pp, 17 Figs. ,  St. Petersburg University Press, 1994,  ISBN 5-288-00773-X  ( in Russian *)

Gennady A. Ryzhikov is a Senior Researcher at the Institute of Physics of St.Petersburg University
Vladimir N. Troyan  is  a  Professor of Physics, Vice-rector for Researches of  St. Petersburg University & Head of Department of Terrestrial Physics :

198904 St.Petersburg
Petrodvorets, Ulianovskaya 1
phone +7  812 4284322
fax +7  812 4287240






Some topics  were  published  also  in   English :

Ryzhikov G.A. and Troyan V.N., 1988,
The solution of an inverse dynamic seismic problem
for three-dimensional inhomogeneous media:
Revista de Geofisica 44, no.2, Madrid, 149-156.

Ryzhikov G.A. and Troyan V.N., 1993,
3D diffraction tomography. Part I:
construction and interpretation of tomography functionals:
Proc. of Russian- Norwegian Oil Exploration Workshop II
5.05-7.05.92, Norsk Hydro Research Centre, Bergen, 41a

Ryzhikov G.A. and Troyan V.N., 1993,
3D diffraction tomography. Part II:
reconstruction algorithm with statistical regularization.
Proc. of Russian- Norwegian Oil Exploration Workshop II
5.05-7.05.92, Norsk Hydro Research Centre, Bergen, 41b

Ryzhikov G.A. and Troyan V.N., 1993,
Diffraction tomography and back-projection,
in  Geophysical Data Interpretation by Inverse Modelling.
Proc. of the 9-th International Seminar on Model
Optimization in Exploration Geophysics.
Berlin 1991. Ed. by  A.Vogel et al, Vieweg. Wiesbaden, 47-52.

Ryzhikov G.A. and Troyan V.N., 1993,
On regularization methods in 3-D ray tomography
in Geophysical Data Interpretation by Inverse Modelling.
Proc. of the 9-th International Seminar
on Model Optimization in Exploration Geophysics.
Berlin 1991. Edited by A.Vogel, Vieweg. Wiesbaden, 37-46.

Also: V.Troyan's lectures "Inverse  seismic  problems"
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Yet in Russian
 
 
 
 
 

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