Optimal Acoustic Measurements

Mathematics – Analysis of PDEs

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

interacting upgoing and downgoing evanescent waves are now excluded

Scientific paper

We consider the problem of obtaining information about an inaccessible half-space from acoustic measurements made in the accessible half-space. If the measurements are of limited precision, some scatterers will be undetectable because their scattered fields are below the precision of the measuring instrument. How can we make measurements that are optimal for detecting the presence of an object? In other words, what incident fields should we apply that will result in the biggest measurements? There are many ways to formulate this question, depending on the measuring instruments. In this paper we consider a formulation involving wave-splitting in the accessible half-space: what downgoing wave will result in an upgoing wave of greatest energy? A closely related question arises in the case when we have a guess about the configuration of the inaccessible half-space. What measurements should we make to determine whether our guess is accurate? In this case we compare the scattered field to the field computed from the guessed configuration. Again we look for the incident field that results in the greatest energy difference. We show that the optimal incident field can be found by an iterative process involving time reversal ``mirrors''. For band-limited incident fields and compactly supported scatterers, in the generic case this iterative process converges to a single time-harmonic field. In particular, the process automatically "tunes" to the best frequency. This analysis provides a theoretical foundation for the frequency-shifting and pulse-broadening observed in certain computations and time-reversal experiments.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Optimal Acoustic Measurements does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Optimal Acoustic Measurements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optimal Acoustic Measurements will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-487113

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.