ESTIMATING THE PARAMETERS OF AN INHOMOGENEOUS MEDIUM BY PROBING WITH RAYS,
Abstract
A computationally efficient technique using ray tracing and successive approximation to estimate the index of refraction of an inhomogeneous medium from the times of arrival of a transmitted signal at various receivers. The ray treatment can cope with a medium whose properties vary in two or three dimensions. The inverse problem can be solved iteratively by a search procedure, by a gradient procedure, or by quadratic convergence. Algorithms for computer solution are presented for quadratic convergence. To conserve high-speed storage, one ray at a time is evaluated until all the rays are considered at each iteration. In a numerical example using fourth-order Adams-Moulton integration with a step size of 0.1, computing time on the IBM 7044 was about half a minute. The initial approximation was a homogeneous medium but the estmate was refined in three iterations. First experiments indicate that the method is feasible even with noisy data. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1969
- Accession Number
- AD0684151
Entities
People
- D. Detchmendy
- Harriet H. Kagiwada
- J. Casti
- Robert E. Kalaba
Organizations
- RAND Corporation