Optimal Electromagnetic Measurements
(2000) In Technical Report LUTEDX/(TEAT-7091)/1-24/(2000)- Abstract
- We consider the problem of obtaining information about an inaccessible halfspace
from electromagnetic 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 optimal measurements? 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 wavesplitting
in the accessible half-space: what downgoing wave will result in... (More) - We consider the problem of obtaining information about an inaccessible halfspace
from electromagnetic 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 optimal measurements? 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 wavesplitting
in the accessible half-space: what downgoing wave will result in an
upgoing wave of greatest energy? This formulation is most natural for far-field
problems.
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, this iterative process converges to a sum
of time-harmonic fields. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/530568
- author
- Cheney, Margaret LU and Kristensson, Gerhard LU
- organization
- publishing date
- 2000
- type
- Book/Report
- publication status
- published
- subject
- in
- Technical Report LUTEDX/(TEAT-7091)/1-24/(2000)
- pages
- 24 pages
- publisher
- [Publisher information missing]
- report number
- TEAT-7091
- language
- English
- LU publication?
- yes
- additional info
- Published version: J. Electro. Waves Applic., 15(10), 1323-1336, 2001.
- id
- 50780362-0dc2-4f08-a610-e124aecb4a2c (old id 530568)
- date added to LUP
- 2016-04-04 14:03:16
- date last changed
- 2018-11-21 21:18:00
@techreport{50780362-0dc2-4f08-a610-e124aecb4a2c,
abstract = {{We consider the problem of obtaining information about an inaccessible halfspace<br/><br>
from electromagnetic measurements made in the accessible half-space.<br/><br>
If the measurements are of limited precision, some scatterers will be undetectable<br/><br>
because their scattered fields are below the precision of the measuring<br/><br>
instrument. How can we make optimal measurements? In other words, what<br/><br>
incident fields should we apply that will result in the biggest measurements?<br/><br>
There are many ways to formulate this question, depending on the measuring<br/><br>
instruments. In this paper we consider a formulation involving wavesplitting<br/><br>
in the accessible half-space: what downgoing wave will result in an<br/><br>
upgoing wave of greatest energy? This formulation is most natural for far-field<br/><br>
problems.<br/><br>
A closely related question arises in the case when we have a guess about the<br/><br>
configuration of the inaccessible half-space. What measurements should we<br/><br>
make to determine whether our guess is accurate? In this case we compare the<br/><br>
scattered field to the field computed from the guessed configuration. Again<br/><br>
we look for the incident field that results in the greatest energy difference.<br/><br>
We show that the optimal incident field can be found by an iterative<br/><br>
process involving time reversal “mirrors”. For band-limited incident fields<br/><br>
and compactly supported scatterers, this iterative process converges to a sum<br/><br>
of time-harmonic fields.}},
author = {{Cheney, Margaret and Kristensson, Gerhard}},
institution = {{[Publisher information missing]}},
language = {{eng}},
number = {{TEAT-7091}},
series = {{Technical Report LUTEDX/(TEAT-7091)/1-24/(2000)}},
title = {{Optimal Electromagnetic Measurements}},
url = {{https://lup.lub.lu.se/search/files/6269475/624952.pdf}},
year = {{2000}},
}