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Imagerie microonde d’objets enterrés : modélisations
numériques bidimensionnelles et étude de l’extension
tridimensionnelle
Ioannis Aliferis
To cite this version:
Ioannis Aliferis. Imagerie microonde d’objets enterrés : modélisations numériques bidimensionnelles
et étude de l’extension tridimensionnelle. Autre. Université Nice Sophia Antipolis; National Technical
University of Athens, 2002. Français. �tel-00165785v2�
Sqol Hlektrolìgwn Mhqanik¸n kai Mhqanik¸n Upologist¸n
Tomèa SusthmtwnMetdosh Plhrofora kai Teqnologa Ulik¸n
Mikrokumatik apeikìnish antikeimènwn sto eswterikì dom¸n: disdistath arijmhtik montelopohsh kai
melèth epèktash sti trei diastsei
DidaktorikhDiatribh Iwnnh Aliferh
antikeimènwn sto eswterikì dom¸n: disdistath arijmhtik montelopohsh kai
melèth epèktash sti trei diastsei
To parìn stoiqeiojet jhke me tosÔsthma paraskeu eggrfwn
L
A
TEX
. H sqedash t selda ègine apì to suggrafèa: o prosektikì anagn¸sth ja anakalÔyei th qrus tomφ
sti difore analoge (odhge ektÔpwsh brskontaisthn teleutaa selda).H hlektronik èkdosh enaidiajèsimhsth selda:
päfìnofriqtänkaÈt¸raxèrei
poiä l jeiaåkìsmo poÌ Íperèqei poiätä{n
˜
un}kaÈpoiätä {aÊàn}to˜
u kìsmou:HmèaSusthmtwnMetdosh Plhrofora kaiTeqnologa Ulik¸n, Sqo-l Hlektrolìgwn Mhqanik¸n kaiMhqanik¸n Upologist¸n, Ejnikì Metsì-bio Poluteqneo (emp), sthn Ellda, kai sto
Laboratoire d’´
Electronique,
Antennes et T´el´ecommunications (leat)
, to opoo an kei apì koinoÔ stoUniversit´e de Nice – Sophia Antipolis (unsa)
kaistoCentre National de la
Recherche Scientifique (cnrs)
,sthGalla.Hparapnwfainomenikapl frsh,krÔbeiènanexairetikmeglobajmì poluplokìthta ,aggzonta taìria toÔ(kbantikoÔ)Qou .
1
KiantoÔthth stigm grfw autì to shmewma, to qrwst¸ kai sth suneisfor kpoiwn pros¸pwn pou me st rixan me ton ènan llo trìpo sthn porea aut t ergasa .
Ekfrzw th baji mou eugnwmosÔnhstou epiblèponte kajhghtè mou, k. Panagi¸th Fragko,Kajhght emp,kai k.
Christian Pichot
, Dieujunt 'Ereunacnrs
kai Dieujunt toÔleat
. MoÔ èdeixan, o kajèna apì thn pleur tou, amèristh sumparstash kaiempistosÔnh kat thn ekpìnhsh t diatrib ,kajodhg¸nta thn ergasamou meupodeigmatikì trìpo. 'Htan dia-jèsimoi opoted pote z thsath bo jei tou , prosfèronta apotelesmatikè lÔsei . Oi polÔwre suzht sei maz tou moÔ prìsferan pnta mi frèskia matisto antikemenìmou kaiènaknhtrogianasuneqsw.Euqarist¸tonk.NikìlaoOuzounoglou,Kajhght emp,giath summeto-q tousthntrimel epitrop ,thnupost rix tousthnidèat sunepbleyh , ti exairetikqr sime gia thn ergasa idèe tou, kaithn apodoq touna o-ristew krit t diatrib apìto
unsa
.Ekfrzwti bajiè euqariste moustonk.
Albert Papiernik
,Kajhghtunsa
,oopoo me upodèqthkew Dieujunt toÔleat
,arqikw metaptu-qiakì spoudast kai sth sunèqeia w upoy fio didktora. Ton euqarist¸ jerm giath summetoq tousthn eptamel epitrop .1
Hèreunaapèdeixeìtiopl rh orismì t ènnoia {didaktorik diatrib upìkajest¸ sunepbleyh }enaiexairetikdÔskolo nadoje. SÔmfwna memiaempeirik prosèggish, prìkeitaigia ènakbantikìfainìmeno meglh klmaka ,sto opoo ènafusikì prìswpo brsketaitautìqronasedÔo mèrhgia ènameglo qronikìdisthma. Seaut thn kat-stash,ènatomosusswreÔeiempeiradekdwnwr¸npt sh (metaantstoiqaqamìgela aerosunod¸n;ìqiìmw kaiarketmliagiaènataxdista
Bora Bora
), enisqÔei apofasi-stik thnpagkìsmia agorthlepikoinwni¸n,parenoqletou upeÔjunou diktÔwnme ta pioapjanateqnikprobl mata(sumbllonta ,upojètw,sthnpro¸jhsht antstoiqh èreuna ),entrufesto SugkritikìDkaio,prospaj¸nta naenarmonistetautìqroname nìmou diaforetik¸nqwr¸n, kaiupoblleiprwtìgnwra ait mata sedhmìsie uphrese , apokt¸nta anagkastikmiastshzenw pro tonèxwkìsmo(ankaidenmpor¸napwto diokaigiathntèqnhsunt rhsh t motosuklèta ). Okatlogo jamporoÔsena sune-qistegiapolÔ,alljamenwseènashmeo: ìsokianfanetaipardoxo,hpijanìthta ìlataparapnwnaèqounasiotèlo ,enaimhmhdenik .jhght Panepisthmou
Ontario
, dèqthke na summetèqei sthn eptamel epi-trop kai na enai krit t diatrib gia toUniversit´e de Nice – Sophia
Antipolis
. Ton euqarist¸ jerm gia ìla, kaiidiatera gia tosuntonismì t diadikasa exètash toÔdidaktorikoÔ apìth jèsh toÔ proèdrout epitro-p .Kat th dirkeia ìlwn aut¸n twn et¸n, eqa thn tÔqh na sunergast¸ polÔ sten me tonk.
Jean-Yves Dauvignac
,Lèktoraunsa
. Ekfrzwthn eugnwmosÔnhmou giathn aperiìristhbo jeia pou moÔpareqese jewrhtik kaiteqnikzht mata, ta arijmhtikapotelèsmata toÔlogismikoÔSR3D
,ti atèleiwte ¸re pou afièrwsesthn ergasamou,kaiti exairetik epoikodo-mhtikè suzht sei poueqame maz.Euqarist¸ thnkaKwnstantnaNikhta, Anaplhr¸tria Kajhg triaemp, gia th summetoq th sthn eptamel epitrop exètash toÔ didaktorikoÔkai ti polÔ qr sime parathr sei th .
O k.
Dominique Lesselier
,Dieujunt 'Ereunacnrs
,dèqthkena ori-stekrit t diatrib . Toneuqarist¸giautì kaj¸ kaigiataexairetik endiafèrontasqìli tou.Ekfrzw ti euqariste mou ston k. Iwnnh Kanellopoulo, Kajhght emp,gia thnparaq¸rhsh enì q¸rouergasa stoemp.
Euqarist¸ ton k. Gi¸rgo Kossiaba, Kajhght
unsa
, thn kaClaire
Migliaccio
, Lèktoraunsa
, kaj¸ kai ìla ta mèlh toÔleat
, gia th bo- jei tou .O k.
John Gilbert
, ereunht stoXerox Palo Alto Research Center
, moÔèdwseulopohshtoÔalgorjmou“Incomplete Lower Upper factorization
with Threshold” (ilut)
sek¸dikaMatlab
,katth dirkeiatoÔseminarou“Sparse Days”
stocerfacs
(IoÔnio 2002,Toulouse
,Galla);toneuqarist¸ gi autì.H ekpìnhsh t diatrib qrhmatodot jhke me upìtrofatoÔ IdrÔmato Kratik¸nUpotrofi¸n(iku). Euqarist¸tonk.Epamein¸ndaKriezh,Omìtimo Kajhght AristoteleouPanepisthmouJessalonkh ,giatasqìlitouapì thjèshtoÔepìpthkajhght . Epsh euqarist¸toproswpikìtoÔIdrÔmato , kaiidiaterati kure Aret Kalogeropoulou,KrustallaKoukoulomath, Iwnna Adamantiadou kaiQrusnnaMetaxa. H yogh sunergasa mou me toikukattodisthmaaut¸ntwnet¸n, moÔepitrèpei natojewr¸ upìdeig-ma dhmìsiou organismoÔ se ì,ti afor thn euelixa, thn katanìhsh kai thn poiìthtatoÔproswpikoÔ tou.
Euqarist¸thnka
G´eraldine Mansueti
,tonk.Christian Raffaele
,thn kaMartine Borro
kai thn kaBèra Eujumiou gia th grammateiak upost -rixh.Ekfrzw ti euqariste mou pro ìlou tou sunadèrfou , se Ellda kai Galla, kai idiatera stou Prìdromo Atlamazoglou, Alèxandro Dh-mou,
Tareq Al Gizawi
,JeofnhManiath,JanshPanagopoulo,Qr sto Papaqrhsto,JanshPotsh,kaiC´edric Dourthe
,Ralph Ferray´
e
,Erw-an GuillErw-anton
,Emmanuel Le Brusq
,Philippe Le Thuc
,Herv´e Tosi
,Christelle Nannini
,Chu Son
.H
Joanna Sosabowska
up rxeosÔndesmì moumetonexwterikìkìsmo katthdirkeiatwntri¸nteleutawnmhn¸nkaigiautìt emaieugn¸mwn. Euqarist¸ toMassimiliano Ma¨ıni
kaithVictorit¸a Dolean
gia th bo -jeia kaith filoxenatou ......kaitoNkoQrusanjakopoulo,genik¸ .
Grfonta autì tokemeno,suneidhtopoi¸gia llh miaforìti se ma-jhmatik dilekto hgl¸ssaapotelemhpl rhbshgiathnperigraf twn sunaisjhmtwn. Gi autì, epilègw na mhn th qrhsimopoi sw llo. Kpoioi, twnopownta onìmatalepoun,jatokatalboun.
2
Anmes tou , oigone mou,Dhm trh kai'Anna,h aderf mou,Polutmh,oGi¸rgo Kourh , kaita anyiamou,DanhkaiPltwna .
Nkaia,Galla Dekèmbrio 2002
2
Apìmìnoitou ? Apìmìnoitou . Qwr naknei tpota? ApolÔtw tpota.
1 Eisagwg 1
1.1 Mikrokumatik apeikìnish . . . 1
1.1.1 Genik perigraf . . . 1
1.1.2 Perijlastik tomografa. . . 3
1.1.3 Pèra apìthn perijlastik tomografa . . . 5
1.1.4 Mh grammikè mèjodoi . . . 6
1.1.5 Kanonikopohsh . . . 8
1.2 Dom didaktorik diatrib . . . 8
I
Disdistath arijmhtik montelopohsh 11 2 Mikrokumatik tomografa 13 2.1 EujÔ prìblhmaskèdash . . . 132.1.1 Orismì . . . 13
2.1.2 Oloklhrwtikè anaparastsei . . . 14
2.1.3 Mèjodo Rop¸n . . . 16
2.1.4 Exis¸sei pinkwn . . . 18
2.2 Antstrofoprìblhmaskèdash . . . 20
2.2.1 Orismì . . . 20
2.2.2 Mèjodo suzug¸nklsewn. . . 21
2.2.3 Mèjodo disuzug¸nklsewn . . . 23
2.2.4 Kanonikopohsh . . . 24
3 Arijmhtik apotelèsmata 29 3.1 Eisagwg . . . 29
3.2 Montelopohsh prospptonto pedou . . . 32
3.3 Montelopohsh metrhtikoÔjorÔbou . . . 33
3.4 Melèthanoq jorÔbou . . . 34
3.6 MelètharijmoÔ suqnot twn . . . 38
3.7 Melèthperioq suqnot twn . . . 38
3.8 Teqnikè metallag suqnìthta . . . 52
3.9 Sumpersmata . . . 55
II
Melèth epèktash sti trei diastsei 61 4 EujÔ prìblhma 63 4.1 Exis¸seiMaxwell
. . . 634.2 Oriakè sunj ke . . . 65
4.3 Sunj khaktinobola . . . 66
4.4 Exis¸sei skedazìmenoupedou . . . 66
5 Mèjodo peperasmènwn diafor¸n 71 5.1 Apìtosuneqè stodiakritì . . . 71
5.2 Arjmhsh tim¸ndiakritopoihmènwnmegej¸n. . . 75
5.2.1 Trisdistata probl mata . . . 75
5.2.2 Disdistata probl mata . . . 76
5.3 KatstrwshgrammikoÔsust mato . . . 77
5.3.1 Probl matakleist gewmetra kaiaktinobola . . . 79
5.3.2 Probl mataskèdash . . . 79
5.4 Efarmog oriak¸nsunjhk¸n . . . 80
5.5 Aporrofhtikè oriakè sunj ke . . . 82
5.5.1 Hlektromagnhtikè idiìthte . . . 84
5.5.2 Qarakthristik didosh . . . 84
5.5.3 Jewrhtikì suntelest anklash . . . 86
5.5.4 Proflagwgimìthta . . . 86
5.6 Metasqhmatismì kontinoÔ semakrinì pedo . . . 88
5.6.1 Olokl rwma
Kirchhoff
. . . 89 5.6.2 Arijmhtik pistopohsh . . . 90 6 Arijmhtik apotelèsmata 97 6.1 Kleistprobl mata . . . 97 6.1.1 Mèjodoieplush . . . 97 6.1.2 Kumatodhgì . . . 98 6.1.3 Suntonizìmenh koilìthta . . . 100 6.2 Anoiqt probl mata . . . 103 6.2.1 Mèjodoieplush . . . 103 6.2.2 Stoiqei¸de dpolo . . . 105 6.3 Sumpersmata . . . 1057 Sumpersmata 107
III
Parart mata 115AþTelest andelta se pnake 117
Aþ.1 Klsh pnaka . . . 117
Aþ.2 Laplasian pnaka . . . 117
Bþ Diakritopohsh diaforik¸n telest¸n 119 Gþ Diakritopohsh exis¸sewn
Maxwell
121 Gþ.1 ExswshFaraday
. . . 121Gþ.2 Exswsh
Maxwell-Amp`ere
. . . 123Gþ.3 Kumatik exswshgia tohlektrikìpedo . . . 125
Gþ.4 Exswsh
Gauss
gia to hlektrikìpedo . . . 128Gþ.5 Klsh t exswsh
Gauss
. . . 130DþKatstrwsh grammikoÔ sust mato 135 Dþ.1 Orismì pinkwnmèsh tim . . . 135
Dþ.2 Exswsh
Faraday
. . . 138Dþ.3 Exswsh
Maxwell-Amp`ere
. . . 140Dþ.4 Kumatik exswshgia tohlektrikìpedo . . . 141
Dþ.5 Klsh t exswsh
Gauss
. . . 141Eþ Pnake periorismènh tautìthta 145 Eþ.1 Orismì kaiidiìthte . . . 145
Eþ.2 Pnaka exwterikoÔagwgoÔ . . . 147
Eþ.3 Pnaka eswterik¸nagwg¸n . . . 148
Eþ.4 Pnaka efarmosmènwndunamik¸n . . . 148
þ Arijmhtik olokl rwsh 149 þ.1 Apl olokl rwsh. . . 149 þ.2 Dipl olokl rwsh . . . 150 Zþ Olokl rwma
Kirchhoff
151 Bibliografa155
Euret rio bibliografa167
ιαʹ
2.1 Gewmetrapollapl¸n strwmtwndisdistatou probl mato . . 15 3.1 Profl dihlektrik stajer kai agwgimìthta pragmatikoÔ
antikeimènou. Oiarijmo stou xone
x, y
anafèrontaise ku-yèle . . . 30 3.2 Apotelèsmataanakataskeu mekanonikopohsh(m.k.) kaiqw-r (q.k.),sunart seitoÔphlkous mato pro jìrubo. Pro-fl gia anakataskeu me kanonikopohsh,
SNR = 20 dB
(p-nw),SNR = 90 dB
(ktw). . . 36 3.3 Omda apotelesmtwn 1. Metabol toÔ arijmoÔ twnshme-wn ekpomp /mètrhsh (
N
M
∈ {3, 5, 7, 11, 13, 21, 31, 61}
) gia stajerìm ko gramm mètrhshL
M
= 1.5 m
. Apotelèsmata qwr kanonikopohsh. Profl giaSNR = 30 dB
,N
M
= 13
(pnw),N
M
= 21
(ktw). . . 39 3.4 Omdaapotelesmtwn 1. Metabol toÔ arijmoÔ twnshmewnekpomp /mètrhsh (
N
M
∈ {3, 5, 7, 11, 13, 21, 31, 61}
) gia sta-jerìm ko gramm mètrhshL
M
= 1.5 m
. Apotelèsmata me kanonikopohsh. Profl giaSNR = 30 dB
,N
M
= 13
(pnw),N
M
= 21
(ktw). . . 40 3.5 Omda apotelesmtwn 2. Metabol toÔ arijmoÔ twnshme-wnekpomp /mètrhsh (
N
M
∈ {3, 5, 9, 11, 21, 41}
) gia staje-rì m ko gramm mètrhshL
M
= 1 m
. Apotelèsmata qwr kanonikopohsh. Profl giaSNR = 30 dB
,N
M
= 21
(pnw),N
M
= 41
(ktw). . . 41 3.6 Omda apotelesmtwn 2. Metabol toÔ arijmoÔ twnshme-wnekpomp /mètrhsh (
N
M
∈ {3, 5, 9, 11, 21, 41}
) gia staje-rì m ko gramm mètrhshL
M
= 1 m
. Apotelèsmata me ka-nonikopohsh. Profl giaSNR = 30 dB
,N
M
= 21
(pnw),N
M
= 41
(ktw). . . 423.7 Omda apotelesmtwn 3. Metabol toÔ arijmoÔ suqnot twn (
N
F
∈ {2, 3, 5, 6, 11, 21}
)giastajer perioq suqnot twn0.3
−
1.3 GHz
. Apotelèsmata qwr kanonikopohsh. Profl giaSNR = 30 dB
,N
F
= 5
(pnw),N
F
= 11
(ktw). . . 43 3.8 Omda apotelesmtwn 3. Metabol toÔ arijmoÔ suqnot twn(
N
F
∈ {2, 3, 5, 6, 11, 21}
)giastajer perioq suqnot twn0.3
−
1.3 GHz
. Apotelèsmatamekanonikopohsh. ProflgiaSNR =
30 dB
,N
F
= 5
(pnw),N
F
= 11
(ktw). . . 44 3.9 Omda apotelesmtwn 4. Metabol t an¸terhsuqnìth-ta
f
max
giastajer kat¸tathsuqnìthtaf
min
= 0.3 GHz
kai arijmì suqnot twnN
F
= 3
. Apotelèsmata qwr kanoniko-pohsh. Profl giaSNR = 30 dB
,f
max
= 0.5 GHz
(pnw),f
max
= 1.3 GHz
(ktw). . . 45 3.10 Omda apotelesmtwn 4. Metabol t an¸terhsuqnìth-ta
f
max
gia stajer kat¸tath suqnìthtaf
min
= 0.3 GHz
kai arijmì suqnot twnN
F
= 3
. Apotelèsmata me kanoniko-pohsh. Profl giaSNR = 30 dB
,f
max
= 0.5 GHz
(pnw),f
max
= 1.3 GHz
(ktw). . . 46 3.11 Omda apotelesmtwn 5. Metabol t an¸terhsuqnìth-ta
f
max
giastajer kat¸tathsuqnìthtaf
min
= 0.3 GHz
kai arijmì suqnot twnN
F
= 5
. Apotelèsmata qwr kanoniko-pohsh. Profl giaSNR = 30 dB
,f
max
= 0.5 GHz
(pnw),f
max
= 1.3 GHz
(ktw). . . 48 3.12 Omda apotelesmtwn 5. Metabol t an¸terhsuqnìth-ta
f
max
gia stajer kat¸tath suqnìthtaf
min
= 0.3 GHz
kai arijmì suqnot twnN
F
= 5
. Apotelèsmata me kanoniko-pohsh. Profl giaSNR = 30 dB
,f
max
= 0.5 GHz
(pnw),f
max
= 1.3 GHz
(ktw). . . 49 3.13 Omdaapotelesmtwn6. Metabol t kentrik suqnìthtaf
0
giastajerìeÔro z¸nhf
max
− f
min
= 0.2 GHz
kaiarijmì suqnot twnN
F
= 3
. Apotelèsmata qwr kanonikopohsh. ProflgiaSNR = 30 dB
,f
0
= 0.4 GHz
(pnw),f
0
= 1.2 GHz
(ktw). . . 50 3.14 Omdaapotelesmtwn6. Metabol t kentrik suqnìthtaf
0
giastajerìeÔro z¸nhf
max
− f
min
= 0.2 GHz
kaiarijmì suqnot twnN
F
= 3
. Apotelèsmata me kanonikopohsh. Pro-fl giaSNR = 30 dB
,f
0
= 0.4 GHz
(pnw),f
0
= 1.2 GHz
(ktw). . . 513.15 Omda apotelesmtwn 7. Metabol t an¸terh suqnìth-ta
f
max
gia stajer kat¸tath suqnìthtaf
min
= 0.3 GHz
, arijmì suqnot twnN
F
= 3
kai metallag suqnìthta . Apo-telèsmata qwr kanonikopohsh. Profl giaSNR = 30 dB
,f
max
= 0.5 GHz
(pnw),f
max
= 1.3 GHz
(ktw). . . 53 3.16 Omdaapotelesmtwn7. Metabol t an¸terh suqnìthtaf
max
giastajer kat¸tathsuqnìthtaf
min
= 0.3 GHz
,arijmì suqnot twnN
F
= 3
kaimetallag suqnìthta . Apotelèsmata mekanonikopohsh. ProflgiaSNR = 30 dB
,f
max
= 0.5 GHz
(pnw),f
max
= 1.3 GHz
(ktw). . . 54 3.17 Omda apotelesmtwn 8. Metabol t kentriksuqnìth-ta
f
0
gia stajerì eÔro z¸nhf
max
− f
min
= 0.2 GHz
, a-rijmì suqnot twnN
F
= 3
kai metallag suqnìthta . Apo-telèsmata qwr kanonikopohsh. Profl giaSNR = 30 dB
,f
0
= 0.4 GHz
(pnw),f
0
= 1.2 GHz
(ktw). . . 56 3.18 Omdaapotelesmtwn8. Metabol t kentrik suqnìthtaf
0
gia stajerì eÔro z¸nhf
max
− f
min
= 0.2 GHz
, arijmì suqnot twnN
F
= 3
kaimetallag suqnìthta . Apotelèsmata me kanonikopohsh. Profl giaSNR = 30 dB
,f
0
= 0.4 GHz
(pnw),f
0
= 1.2 GHz
(ktw). . . 57 5.1 Stoiqei¸dh kuyèlh(i, j, k)
toÔ plègmato . . . 72 5.2 GwniakTèleia ProsarmosmènaStr¸mata. . . 85 5.3 Diaqwristik epifneiaTèleiouProsarmosmènouStr¸mato . 85 5.4 PollaplTèleiaProsarmosmèna Str¸mata. . . 87 5.5 Aktinobola stoiqei¸dou dipìlou stomakrinì pedo:sÔgkri-sh analutikoÔ upologismoÔ kai metasqhmatismoÔ kontinoÔ se makrinì pedo. Upologistikì q¸ro :
(23, 23, 23)
kìmboi. Epi-fneiaKirchhoff
: apì(2, 2, 2)
w(22, 22, 22)
, m ko pleur1λ
,kentrarismènh. . . 91 5.6 AkrbeiametasqhmatismoÔ kontinoÔse makrinìpedosunart -sei toÔm kou
d
t pleur toÔ kÔbouKirchhoff
(epifneia kentrarismènh). . . 92 5.7 AkrbeiametasqhmatismoÔ kontinoÔse makrinìpedosunart -sei t jèsh toÔ kÔbou
Kirchhoff
. Mhdenikìoffset
antistoi-qesekentrarismènokÔbo. Upologistikì q¸ro :(43, 43, 43)
kìmboi. EpifneiaKirchhoff
: m ko pleur 20 kuyèle (1λ
). 94 5.8 AkrbeiametasqhmatismoÔ kontinoÔse makrinìpedosunart -sei twndiastsewn t kuyèlh . Epifneia
Kirchhoff
: m ko pleur1λ
,kentrarismènh. . . 955.9 Aktinobola stoiqei¸dou dipìlou stomakrinì pedo: sÔgkri-sh analutikoÔ upologismoÔ kai metasqhmatismoÔ kontinoÔ se makrinì pedo. Diastsei kuyèlh :
λ/120
. . . 96 6.1 Sunist¸saE
y
toÔhlektrikoÔpedoutwnrujm¸nTEz
10
(pnw) kaiTEz
20
(ktw) enì kumatodhgoÔ orjogwnik diatom , mea/b = 3
. Oiarijmostou xonex, y
anafèrontaise kuyèle . 101 6.2 Sunist¸saE
y
toÔ hlektrikoÔ pedoutwn rujm¸n TEz
101
(p-nw)kaiTEz
201
(kèntro), kaisunist¸saE
z
toÔrujmoÔTMz
110
(ktw)gia mia orjogwnik koilìthta,me
a/b = 3
kaia/c = 2
. 104 6.3 Aktinobolastoiqei¸dou dipìloustomakrinìpedo: sÔgkrishanalutikoÔupologismoÔ kaiarijmhtikoÔ pedoupeperasmènwn diafor¸n. . . 106
3.1 Parmetroidiakritopohsh q¸rou
D
d
. . . 31 3.2 Parmetroikanonikopohsh .. . . 31 5.1 Suntetagmène pediak¸n sunistws¸nsthn kuyèlh(i, j, k)
. . . 72 6.1 Lìgo suqnot twnR
mn
= f
mn
/f
10
gia kumatodhgìorjogw-nik diatom ,me
a/b = 3
. . . 99 6.2 Lìgo suqnot twnR
mnp
= f
mnp
/f
101
gia orjogwnikEisagwg
Nuntägrmit
˜
h murti˜
a N˜
unkraugto˜
uMh AienkrasunedhshAÊànplhsifh1.1 Mikrokumatik apeikìnish
1.1.1 Genik perigraf
O ìro {mikrokumatik apeikìnish} perigrfei èna sÔnolomejìdwn ana-kataskeu twn idiot twn enì gnwstou antikeimènou, qrhsimopoi¸nta w phg plhrofora thn allhlepdrash toÔ antikeimènou me hlektromagnhtik aktinobola mikrokumatik¸n suqnot twn. Oi zhtoÔmene idiìthte mpore na perilambnounth jèsh, tosq ma, ta hlektromagnhtikqarakthristik (apì ta opoampore naprokÔyei hsÔstash), ènasunduasmì twnparapnw. H paroÔsaergasaexetzeithmikrokumatik apeikìnishmikr embèleia ,ìpou h ditaxh ekpomp kai mètrhsh brsketai se mikr apìstash apì to upì melèthantikemeno.
Ta teleutaa ekosi qrìnia èqei ekdhlwje meglo endiafèron gia mejì-dou apeikìnish me qr sh mikrokumtwn. H mikrokumatik apeikìnish èqei efarmostew teqnik mh katastrofikoÔelègqouse kt ria, sthn anqneush metallik¸n dihlektrik¸n antikeimènwn, ìpw oi nrke kat proswpikoÔ, kaj¸ epsh kaisthnperioq t bioðatrik , giathnapeikìnish biologik¸n ist¸n.
MporoÔme na orsoume difore kathgore mejìdwn, me bsh mia sei-r krithrwn, ìpw enai h gewmetra t metrhtik ditaxh , to jewrhtikì montèlo pou qrhsimopoietai kai to edo t plhrofora pou dnei h kje mèjodo .
H disdistath apeikìnish gia thn opoaqrhsimopoietai kaioìro {to-mografa} dneiplhroforagiamia egkrsiatom toÔantikeimènou,en¸an h plhroforaperigrfei olìklhrotoantikemeno,prìkeitai giatrisdistath
To antikemenomporenabrsketaistoneleÔjeroq¸ro, stoeswterikì enì mèsoumegnwstè idiìthte ,sthn perptwsht mikrokumatik apeikì-nish stoeswterikì dom¸n.
Hhlektromagnhtik aktinobola,methnopoaallhlepidrtoupìexètash antikemeno,pargetaiapìma perissìtere kerae ekpomp . To apotèle-smaaut t allhlepdrash metriètaiapìma perissìtere kerae l yh . Topl jo kaihgewmetrik ditaxhtwnekpomp¸nkaitwndekt¸n,apoteloÔn epiplèon qarakthristik twn diafìrwn mejìdwn. Mia ditaxh {pollapl prìsptwsh } (
multiview
) qrhsimopoie perissìterou toÔ enì ekpompoÔ , isodÔnama ènan ekpompì pou metakinetai. O ìro {pollapl mètrhsh } (multistatic
) perigrfei th mètrhshtoÔanakl¸menou hlektromagnhtikoÔ kÔ-mato apì polloÔ dèkte , apì èna dèkth pou metakinetai. Se ì,ti afor th morf toÔ prospptonto kÔmato , mporoÔme nadiakrnoumeti mejìdou sto pedo toÔ qrìnou kai sto pedo t suqnìthta ; sthn paroÔsa ergasa anaferìmastesti teleutae .To prìblhma pou kaletai na lÔsei mia mèjodo mikrokumatik apeikìni-sh , enai o prosdiorismì toÔ gnwstou antikeimènou, me bsh th mètrhsh toÔ skedazìmenoupedou, ìtan to prosppton pedoenai gnwstì. Prìkeitai dhlad giaènaprìblhmaantstrofh skèdash . To antstoiqoeujÔ prìblh-ma enai h eÔresh toÔ skedazìmenou pedou apì èna gnwstì antikemeno, me dedomènotoprospptonpedo. Oipoiotikè (
qualitative
) mèjodoiapeikìnish dnounplhroforagiathnÔparxh,thjèshkaitosq matoÔantikeimènou,en¸ oiposotikè (quantitative
) mèjodoi anakataskeuzounepsh ti hlektroma-gnhtikè tou idiìthte .To prìblhma antstrofh skèdash enai mh kal¸ orismèno (
ill-posed
) (Hadamard
, 1923,Colton and Kress
, 1992), dhlad toulqisto maapì ti paraktwsunj ke denikanopoietai:1. 'Uparxh t lÔsh . 2. Monadikìthtat lÔsh .
3. Omal exrthsht lÔsh apìta dedomèna.
Se mia pr¸thmati, h ikanopohsh t pr¸th sunj kh mporena fane-tai dedomènh, afoÔ to antikemeno pou èdwse to skedazìmeno pedo uprqei. 'Omw , h mètrhsh toÔ skedazìmenoupedouperièqei anapìfeukta jìrubo;an htrth sunj khdenikanopoietai,tìte mporetadedomènamaz metojìrubo na mhn antistoiqoÔn se kamma lÔsh. Sqetik me th deÔterh sunj kh, èqei apodeiqte ìti h mh monadikìthta t lÔsh ofeletai se mh aktinoboloÔse phgè reumtwn
(Devaney and Wolf, 1973, Devaney and Sherman, 1982)
. Prìkeitaigia epag¸mene reumatikè katanomè oiopoe dedhmiourgoÔn pe-do sta shmea ìpou gnetai h mètrhsh(Habashy and Oristaglio, 1994)
, meapotèlesmatometroÔmenoskedazìmenopedonamhn perièqeiplhroforagia thn anasÔnjes tou . H trth sunj kh anadeiknÔei th shmasa pou èqei h elaqistopohshtoÔmetrhtikoÔjorÔbougiathnpoiìthtat anakataskeu . Epiplèon, oi mèjodoi mikrokumatik apeikìnish prèpei na enai anjektikè sto metrhtikì jìrubo, kaj¸ h parousa tou denmpore na exaleifje ente-l¸ . Shmei¸noume ìti apì th skopi t jewra poluplokìthta , èna mh kal¸ topojethmènoprìblhmamporenaenaiakìmakaimh epilÔsimo
(Traub,
1999)
.HsunrthshtoÔq¸roupoudneiti idiìthte toÔantikeimènou(h {sunr-thshantikeimènou}) èqeipolÔplokh, mh grammik exrthshapì ti timè toÔ skedazìmenou pedou, oi opoe apoteloÔn ta dedomèna toÔ probl mato . H mh grammikìthta toÔantstrofouprobl mato ofeletaista fainìmena pol-lapl¸n anaklsewn toÔ prospptonto hlektromagnhtikoÔ kÔmato
(Chew,
1995)
,ta opoaekdhl¸nontaipioèntonasti uyhlè suqnìthte(Chew and
Lin, 1995)
.1.1.2 Perijlastik tomografa
Oi pr¸te mejìdoi mikrokumatik apeikìnish parousisthkan sti ar-qè t dekaeta toÔ1980,tìsogiaantikemenastoneleÔjeroq¸ro
(Adams
and Anderson, 1982)
ìsokaistoeswterikìdom¸n,meefarmog sth bioðatri-k(Bolomey et al., 1982, Baribaud et al., 1982)
. Autè oimèjodoi qrhsimo-poioÔnthnperijlastik tomografa(diffraction tomography, dt
),miateqnik pou efarmìsthkegia pr¸th for sthn apeikìnish uper qwn(Mueller et al.,
1979)
en¸jewrhtik tangnwst arketpalaiìtera(Wolf, 1969, Iwata and
Nagata, 1975)
.H perijlastik tomografa mpore na jewrhje epèktash t upologi-stik tomografa (
computerized tomography, ct
). Lambnei upìyh th mh eujÔgrammhdidoshtwnhlektromagnhtik¸nkumtwn,en¸hupologistik to-mografa pouqrhsimopoietaisthnapeikìnishmeaktne q jewredidosh seeujeagramm . ToolikìpedostoeswterikìtoÔgnwstouskedast pro-seggzetaisÔmfwnameti upojèseiBorn
Rytov
. Sthsunèqeia,toje¸rhma probolik perjlashFourier (Wolf, 1969, Iwata and Nagata, 1975, Slaney
et al., 1984)
dnei mia grammik sqèsh anmesa sth sunrthsh antikeimènou kaitometroÔmenoskedazìmenopedo.SÔmfwna metoje¸rhmaautì toopooenaihepèktash toÔ metasqhma-tismoÔ
Radon
sthn perptwsh t mh eujÔgrammh didosh gia ènas¸ma sto opoo prospptei èna eppedo kÔma, o qwrikì metasqhmatismìFourier
toÔskedazìmenoupedou,metrhmèno pnwse mia eujeakjethsth dieÔjun-sh didosh toÔ prospptonto kÔmato , sumpptei me èna tìxo kÔklou toÔ disdistatouqwrikoÔmetasqhmatismoÔFourier
t sunrthsh antikeimènou.H qr sh pollapl¸n gwni¸n prìsptwsh kaj¸ kai diaforetik¸n suqnot -twnèqei w apotèlesma thn ankthsh olìklhroutoÔqwrikoÔ fsmato t sunrthsh antikeimènou, toopoo, mèswenì antstrofoumetasqhmatismoÔ
Fourier
,dneiti idiìthte toÔantikeimènou.Hperijlastik tomografadneiapotelèsmatasqedìnsepragmatikì qrì-no, afoÔ oi basiko upologismo apoteloÔntai apì gr gorou metasqhmati-smoÔ
Fourier
se makaidÔodiastsei . Hdiakritik ikanìthta t mejìdou isoÔtai jewrhtik meλ/2
,ìpouλ
tom ko kÔmato sto eswterikì toÔ ske-dast ,all sthn prxhautìtoìriodÔskolaepitugqnetai(Paoloni, 1987)
. OimèjodoipouqrhsimopoioÔnperijlastik tomografasunantoÔndÔo pe-riorismoÔ . O èna enaiìti oidèkte prèpei naisapèqoun,kaihmetaxÔtou apìstash na enai mikrìterh sh apì misì m ko kÔmato . O periorismì autì proèrqetaiapìtoje¸rhmadeigmatolhya toÔShannon
kaisqetzetai me to gegonì ìti oi dèkte prèpei na deigmatolhptoÔn me ikanopoihtikì qw-rikìrujmì to skedazìmenopedo. OdeÔtero periorismì proèrqetaiapìth qr shtwnproseggsewnBorn
Rytov
giatoolikì pedostoeswterikìtoÔ skedast(Habashy et al., 1993)
. GianaisqÔeihprosèggishBorn
,to ginìme-not diamètroutoÔskedast eptosqetikìdekthdijlas touprèpeina enaimikrìteroapì0.25λ
. GiathnprosèggishRytov
denuprqeiperiorismì stomègejo toÔskedast ,allodekth dijlash toÔantikeimènouprèpei nadiafèreiligìteroapì2%
apìekenontoÔexwterikoÔmèsou(Slaney et al.,
1984)
. Oisunj ke autè deqnounìti topedoefarmog t perijlastik tomografa enaisqetik periorismèno.Ma lÔsh giana arjeodeÔtero periorismì , enainamh qrhsimopoihje kpoiaprosèggish gia topedostoeswterikì toÔskedast . Aut h tropo-pohsh t perijlastik tomografa dneimia grammik sqèsh anmesasta epag¸mena reÔmata sto eswterikì toÔ skedast kai sto metroÔmeno skeda-zìmenopedo
(Pichot et al., 1985)
. Prìkeitai plèon giamia mèjodopoiotik apeikìnish h opoa èqei efarmoste sth bioðatrik kai to mh katastrofikì èlegqo(Tabbara et al., 1988)
. Hmèjodo aut dejèteiperiorismoÔ w pro to mègejo kai to edo twn skedast¸n, all mpore,se orismène peript¸-sei ,naodhg seiseartifacts (Bolomey and Pichot, 1991)
.Togegonì ìtihperijlastik tomografaepilÔeiènagrammikìprìblhma, upodhl¸neiìtitafainìmenapollapl anklash delambnontaiupìyh. To gegonì autì, se sunduasmì me tou parapnw perioristikoÔ pargonte , ¸jhsethnèreunasepiosÔnjete mejìdou mikrokumatik apeikìnish . P-ntw ,h perijlastik tomografa brskei efarmog akìma kais mera se su-st mata anqneush antikeimènwn mèsasth gh
(Hansen and Johansen, 2000,
Cui and Chew, 2000)
,ìtan htaqÔthta epexergasa enaipioshmantik apì thn akrbeiatoÔ apotelèsmato .1.1.3 Pèra apì thn perijlastik tomografa
Sthn prospjeia na dieurunje to pedo efarmog¸n t mikrokumatik apeikìnish kai se skedastè gia tou opoou den isqÔoun oi propojèsei t perijlastik tomografa , anaptÔqjhkan pollè teqnikè . Koinì qara-kthristikìsqedìnìlwnaut¸ntwnmejìdwnenaihepanalhptik eplushenì grammikopoihmènouprobl mato . Oiperissìtere teqnikè qrhsimopoioÔn th mèjodotwn rop¸n gia na perigryoun kaina diakritopoi soun toeujÔ prì-blhmaskèdash
(Richmond, 1965)
.Oi
Wang and Chew (1989)
prìteinan thn Epanalhptik MèjodoBorn
(Born Iterative Method, bim
) thn opoa sth sunèqeia epèkteinan sthn Pa-ramorfwmènhEpanalhptik MèjodoBorn
(Distorted Born Iterative Method,
dbim
)(Chew and Wang, 1990)
, deqnonta ìti h pr¸th enai pio anjektik stojìrubo,en¸h deÔterhparousizeigrhgorìterhsÔgklish.Mia epanalhptik teqnik pou qrhsimopoie th mèjodo
Newton-Kantoro-vich (nk)
giadisdistathposotik apeikìnishstoneleÔjeroq¸ro, protjh-keapìtouJoachimowicz et al. (1991)
. Togegonì ìtitoprìblhmaenaimh kal¸ orismèno, antimetwpzetai me th qr sh kanonikopohsh tÔpouTikho-nov
,en¸sthdiadikasaanasÔnjesh mporenaeisaqjeopoiad potea priori
plhroforasqetikmetopergrammatoÔantikeimènoukaiti akrìtate timè twnhlektromagnhtik¸ntouparamètrwn.H mèjodo
Newton-Kantorovich
(prìkeitai gia epèktash sthn perptw-sh twn sunarthsioeid¸n t mejìdou eÔresh elaqstou toÔNewton
) èqei epsh qrhsimopoihje gia thn eÔresh toÔ sq mato disdistatwn metalli-k¸n skedast¸n ston eleÔjero q¸ro(Roger, 1981)
. Hnk
enai isodÔnamh me thn Epanalhptik Paramorfwmènh MèjodoBorn
, ìpw kai me th mèjodoLevenberg-Marquardt (Franchois and Pichot, 1997)
.'Eqounparousiasteepsh mhepanalhptikè mèjodoi,pouqrhsimopoioÔn yeudo-antistrof upìthnènnoiaelqistwntetrag¸nwn,giathn eplushtoÔ antstrofouprobl mato
(Caorsi et al., 1993, 1994)
.Shmei¸noumeepsh thnprìsfathepèktasht perioq isqÔo t pro-sèggish
Rytov
kaithqrhsimopohshaut t tropopoihmènh mejìdousthn eplush toÔ antstrofou probl mato me epanalhptikì trìpo(Kechribaris,
2001, Kechribaris et al., 2003)
.'Ole autè oi teqnikè dnoun apotelèsmata posotik apeikìnish se peript¸sei skedast¸n oiopooi brskontaiektì orwnisqÔo t perijla-stik tomografa .
1.1.4 Mh grammikè mèjodoi
Oimhgrammikè mèjodoibaszontaigeniksemiaepanalhptik diadikasa. Prìkeitaigia mejìdou antstrofh skèdash ,ìpou ènasunarthsioeidè ,to opoo apotele mètro gia thn katallhlìthta t lÔsh se kje epanlhyh, diathre ton pl rh mh grammikì qarakt ra toÔ probl mato , qwr kamma prosèggish.
Hmèjodo t Tropopoihmènh Bajmda (
Modified Gradient, mg
)(Klein-man and van den Berg
, 1992) jewre w agn¸stou tìso th sunrthsh a-ntikeimènou ìsokaitoolikì pedostoeswterikìautoÔ. Tosunarthsioeidè pou kataskeuzetai me bsh aut th mèjodo apoteletai apì dÔo ìrou . O pr¸to deqnei thn apìstash anmesa sto skedazìmeno pedo anafor kai to skedazìmenopedo apì toanakataskeuasmèno antikemenot trèqousa epanlhyh . OdeÔtero ìro deqneikat pìsotoolikì pedosto eswteri-kì toÔ antikeimènou, sthn trèqousa epanlhyh, ikanopoie ti exis¸sei t hlektromagnhtik jewra . Me autìn ton trìpo, hmg
epilÔei tautìqrona tìsotoeujÔ prìblhmaskèdash ,me qr sht mejìdoutwnrop¸n,ìsokai toantstrofo.Beltiwmène exis¸sei enhmèrwsh twnagn¸stwnèqounw apotèlesmath dieÔrunshtoÔpedouefarmog¸nth ,ìswnaforti diastsei kaitodekth dijlash touskedast
(Kleinman and van den Berg, 1993)
. Hmèjodo èqei efarmostesthn eÔresht jèsh kaitoÔsq mato metallik¸nantikeimènwn ston eleÔjero q¸ro(Kleinman and van den Berg, 1994)
, èqei sunduaste me mèjodo kanonikopohsh tÔpou {olik metabol }(van den Berg and
Kleinman, 1995)
kaièqei qrhsimopoihje gia poiotik(Souriau et al., 1996)
kaiposotik(Lambert et al., 1998)
tomografastoeswterikì dom¸n.H mèjodo tropopoihmènh bajmda dnei sugkrsimaapotelèsmata me e-kena t
Newton-Kantorovich
, all enai perissìtero anjektik se uyhlè stjme jorÔbou(Belkebir et al., 1997)
. Apotelèsmata apeikìnish metalli-k¸nantikeimènwnstoneleÔjeroq¸romebsh pragmatikdedomèna metr se-wnèqounepsh dhmosieute(van den Berg et al., 1995)
.Beltwsht mejìdouapotelehqr shphg¸nantjesh stoformalismì toÔprobl mato
(Habashy and Oristaglio, 1994, Bloemenkamp and van den
Berg, 2000)
. H perigraf toÔ pedoustoeswterikì toÔ skedast me olikè sunart sei bsh (epallhlaeppedwnkumtwn)mei¸neikatpolÔton arij-mì twn agn¸stwn kai ellatt¸nei to upologistikì kìsto(Maniatis, 1998,
Maniatis et al., 2000)
.To gegonì ìti to eujÔ prìblhma den epilÔetai se kje epanlhyh toÔ antstrofou, dnei sth mèjodotropopoihmènh bajmda to pleonèkthma t taqÔthta . Tautìqrona, ìmw , autì jèteikpoiou periorismoÔ w pro to mègejo kaitodekthdijlash twnpro anakataskeu antikeimènwn(
Klein-man and van den Berg
,1993).Miallh prosèggishepilÔei epanalhptiktoantstrofoprìblhma,all se kje epanlhyh to antstoiqo eujÔ prìblhma lÔnetai pl rw
(Harada
et al., 1995)
. To sunarthsioeidè aut t oikogèneia mejìdwn apoteletai mìno apì tonpr¸to ìrotoÔsunarthsioeidoÔ t tropopoihmènh bajmda , autìndhlad pou anafèretai sto skedazìmenopedo. H elaqistopohs tou gnetai qrhsimopoi¸nta th mèjodo twn suzug¸n bajmdwn sth mh grammik th morf(Nazareth, 1996)
.Hparapnwteqnik ,sesunduasmìmethmèjodotwnrop¸ngiathn eplu-sh toÔ eujèo probl mato , èqei efarmoste sth mikrokumatik tomografa metallik¸n antikeimènwn ston eleÔjero q¸ro me bsh sunjetik
(Lobel
et al., 1997a)
kai peiramatik(Lobel et al., 1997b)
dedomèna kaj¸ kai se dihlektrik antikemena sto eswterikì dom¸n(Dourthe et al., 2000c,b,
Aliferis et al., 2000c)
.H qr sh twnPeperasmènwn Stoiqewn, gia thn eplush toÔ eujèo pro-bl mato ,èqeiprotajegiathnapeikìnishdisdistatwnmetallik¸n(
Bonnard
et al.,
1998) kai dihlektrik¸n(Rekanos et al., 1999, Bonnard et al., 2000)
antikeimènwn stoneleÔjeroq¸ro.Oi ergase pou èqoume anafèrei w t¸ra, exetzoun apokleistik thn egkrsiamagnhtik pìlwsh. Giathnperptwsht egkrsia hlektrik pì-lwsh ,mporoÔmenaanafèroumeti ergase twn
Ma et al. (2000)
kaiRekanos
and Tsiboukis (2000)
. Anafèroumeakìmati mejìdou anakataskeu basi-smène stalevel sets (Dorn et al., 2000, Ito et al., 2001, Ramananjaona et al.,
2001, Ferray´e et al., 2003)
kaj¸ kaiepsh ekene pouqrhsimopoioÔn gene-tikoÔ algìrijmou(Caorsi et al., 2000, Pastorino et al., 2000)
kaineurwnik dktua(Wang and Gong, 2000, Rekanos, 2001)
gia thn elaqistopohsh toÔ sunarthsioeidoÔ .Anmesasti enallaktikè proseggsei toÔprobl mato t mikrokuma-tik apeikìnish ,shmei¸noumeed¸thmontelopohshtoÔantikeimènoume b-shmia parametrik morf ,gegonì pouodhgesemeiwmènoarijmì agn¸stwn all sthn anasÔnjesh enì isodÔnamou antikeimènou
(Budko and van den
Berg, 1999, Miller et al., 2000, Sato et al., 2000)
,kaiepsh th qr sh teqni-k¸nepexergasa s mato(Morris et al., 1995, Sahin and Miller, 2001)
.Oi epanalhptikè mh grammikè teqnikè qreizontai ti parag¸gou toÔ sunarthsioeidoÔ w pro th sunrthsh toÔgnwstou antikeimènou. Oi su-narthsiakè pargwgoi kat
Fr´echet (C´ea, 1971)
mporoÔn na upologistoÔn se kleist morf , me bsh ton orismì tou , ìpw sumbanei sthn ergasa twnDourthe et al. (2000c)
. MporoÔn epsh na upologistoÔn èmmesa(Nor-ton, 1999)
akìmakaiarijmhtik,me autìmathparag¸gish(Coleman et al.,
2000)
. Searketè teqnikè apeikìnish qrhsimopoietaitoprosarthmèno prì-blhma gia ton èmmeso upologismì twn sunarthsiak¸n parag¸gwn(Roger,
1982, Roger et al., 1986)
.1.1.5 Kanonikopohsh
Oi teqnikè kanonikopohsh qrhsimopoioÔntai gia na antimetwpiste to gegonì ìti toprìblhma antstrofh skèdash enaimh kal¸ orismèno. Oi teqnikè autè prosjètoun ènanìro stosunarthsioeidè kai odhgoÔnthn e-panalhptik diadikasa eplush pro mia lÔsh me epijumht qarakthristik. Meautìntontrìpo,hmonadikìthtat lÔsh toÔprobl mato apokajsta-tai. Hkanonikopohsheisgeistonalgìrijmo
a priori
plhroforasqetikme thmorf t lÔsh . Giapardeigma,miatètoiaplhroforamporenaenaiìti h sunrthsh antikeimènouenai omal , qwr asunèqeie . Autì otÔpo ka-nonikopohsh(Tikhonov and Arsenin, 1977)
odhgeseantikemenomeomalì profl dihlektrik stajer kai agwgimìthta . H kanonikopohsh me diat -rhsh asuneqei¸n(Lobel et al., 1997a)
kateujÔnei th lÔsh pro antikemena twn opown to profl apoteletai apì omoiogene z¸ne , qwrismène meta-xÔ tou apì asunèqeie . H diat rhsh asuneqei¸n perigrfei ta pragmatik antikemenakalÔtera apìì,ti h teqnikTikhonov (Lobel et al., 1997b)
.1.2 Dom didaktorik diatrib
H diatrib apoteletai apì dÔo mèrh. To pr¸to mèro , afierwmèno sto disdistato prìblhma, xekinei me to deÔtero keflaio. Parousizoume mia mèjodomikrokumatik tomografa hopoaanaptÔqjhkesta plasiatwn er-gasi¸ntoÔ
Dourthe (1997)
. Prìkeitaigiamiamèjodomh grammik tomogra-fa , h opoa qrhsimopoie th mèjodotwn rop¸n gia thn eplushtoÔ eujèo probl mato sekjeepanlhyh. Hmèjodo enaipollapl suqnìthta , pol-lapl prìsptwsh kaipollapl mètrhsh ,me pìlwshegkrsiamagnhtik . Perigrfoume th majhmatik morf toÔeujèo kaitoÔantstrofou probl -mato , kaj¸ kai thn teqnik kanonikopohsh me diat rhsh asuneqei¸n, h opoa akoloujetai apì mia suz thsh sqetik me ton trìpo leitourga th . Totrtokeflaioarqzeimeti belti¸sei pouknamesthmèjodoapeikìnish toÔdeÔteroukefalaou: th montelopohsh toÔprospptonto pedoukaitoÔ jorÔbou mètrhsh . Sth sunèqeia, parousizoume mia seir apotelesmtwn, ta opoaapoteloÔntai apìènapl jo parametrik¸nmelet¸n.StodeÔteromèro ,meletoÔmethnepèktasht mejìdouapeikìnish sthn trisdistath perptwsh. Sta plasia t diatrib , h melèth estizetai sto eujÔtrisdistatoprìblhma. Hmajhmatik perigraf toÔprobl mato dnetai sto tètarto keflaio. H arq gnetai me ti exis¸sei toÔ
Maxwell
gia to olikìpedostoq¸rosuqnot twn,gianad¸soumestotèlo toÔkefalaouti hlektromagnhtikè exis¸sei toÔskedazìmenoupedou. Ekmetalleuìmenoithn omoiìthtatwnexis¸sewnsti dÔoautè peript¸sei ,mporoÔmenaqeiristoÔmeme trìpoomoiìmorfohlektromagnhtikprobl mata diafìrwneid¸n.
Sto pèmpto keflaio, parousizoume mia mèjodo peperasmènwn diafo-r¸nstopedotwnsuqnot twn(
Finite-Difference Frequency-Domain, fdfd
) (Beilenhoff and Heinrich
, 1992). Kaj¸ aut h mèjodo ja qrhsimopoihje seènank¸dikaapeikìnish giathneplushtoÔeujèo probl mato , jewroÔ-me ìti oi plhrofore sqetik me to skedast enai periorismène . Gi autì to lìgo, epilègoume to klasikì kubikì plègma toÔYee (1966)
gia na dia-kritopoi soume ti hlektromagnhtikè exis¸sei . Mia mèjodo apeikìnish dejamporoÔsenaekmetalleujeti idiìthte enì beltiwmènouplègmato giapardeigma,kampullìgrammwnsuntetagmènwn prosarmostikì kaj¸ , ex orismoÔ, to antikemeno sto opoo ja èprepe na prosarmoste to plèg-ma, enaignwsto. Exllou, oikubikè kuyèle enai hfusik epèktash twn tetrgwnwn kuyel¸n (pixels
) t disdistath perptwsh . Me th bo jeia twn pararthmtwn Bþ w Eþ, parousizoume th diakritopohsh twn hlektro-magnhtik¸nexis¸sewnkaitogrammikìsÔsthma pouprokÔptei. Frontzoume naemfansoumerhtti hlektromagnhtikè idiìthte toÔq¸rouupologismoÔ sth majhmatik morf toÔ grammikoÔ sust mato . Autì enai aprathto ¸-ste na mporèsoume na qrhsimopoi soume aut th mèjodo se sunduasmì me ti teqnikè toÔdeÔteroukefalaou. Sth sunèqeia,upenjumzoumeta basik stoiqea t jewra twnaporrofhtik¸nstrwmtwn,ta opoa qrhsimopoioÔ-ntai gia ton termatismì toÔplègmato t mejìdoupeperasmènwn diafor¸n. To keflaio oloklhr¸netai me thn anptuxhmia mejìdoumetasqhmatismoÔ toÔ kontinoÔ se makrinì pedo, basismènh sto olokl rwmaKirchhoff
. Oi a-rijmhtikè pistopoi sei deqnoun ìti autì o metasqhmatismì dnei akrib apotelèsmata,qwr praktiknaepiblleiperiorismoÔ sti paramètrou t mejìdoupeperasmènwndiafor¸n.To èkto keflaio apoteletai apì arijmhtik apotelèsmata t mejìdou peperasmènwndiafor¸n. Giatakleistprobl mata,upologzoumeta idiodia-nÔsmata toÔ pnaka toÔ grammikoÔsust mato . Gia ta anoiqt probl mata, todeÔteromèlo toÔgrammikoÔsust mato denenaimhdenikì,kai prèpeina antistrèyoumeènanpnakaarai morf . Giatoskopìautì,qrhsimopoioÔme epanalhptikè mejìdou
(Saad, 1996)
kai katllhle teqnikèprecondition-ing (Bruaset, 1995)
.To èbdomo keflaio perièqei ta sumpersmata t diatrib . Anakefa-lai¸noumetabasikshmeakaiexetzoumeti prooptikè aut t ergasa . H diatrib perilambnei eptparart mata: topr¸toanafèretaisto deÔ-terokeflaio,kaita upìloipa stopèmpto.
Mèro
I
Disdistath arijmhtik
Mikrokumatik tomografa
N
˜
unn˜
unparasjhshkaÈto˜
uÕpnoumimik AÊànaÊànålìgo kaÈTrìpi strikStokeflaioautìparousizoumesesuntomamiamèjodomikrokumatik tomografa hopoaanaptÔqjhkestaplasia twnergasi¸n
(Dourthe, 1997)
kai(Dourthe et al., 2000a)
. Hmèjodo aut apoteletoenarkt rioshmeot paroÔsa didaktorik diatrib . MebshthjewraautoÔtoÔkefalaou,ja parousisoume mia seir arijmhtik¸n apotelesmtwn stoepìmeno keflaio, exereun¸nta ti dunatìthte kaitoÔ periorismoÔ t mejìdou.2.1 EujÔ prìblhma skèdash
2.1.1 Orismì
JewroÔme ènahlektromagnhtikìprìblhma ametblhtow pro metatop-sei kattonxona
z
. Sthnperptwshaut ,ìlata megèjhtoÔprobl mato enai anexrthta apì th metablhtz
. Anupojèsoume epiplèon ìti to magnh-tikìpedoenaiegkrsiostonxonasummetra ,tìtetohlektrikìpedoèqei mìno ma mh mhdenik sunist¸sa,E(ρ, ω) = E
z
(ρ, ω)ˆ
z
1
ìpou
ρ = xˆ
x + y ˆ
y
. Ta parapnw perigrfoun èna disdistato prìblhma egkrsia magnhtik pìlwsh ,2D
-TM.2
Giaanomoiogen probl matamhmagnhtik¸nmèswn,seperioqè toÔq¸rou qwr phgè reÔmato kaifortwn,tohlektrikìpedoikanopoieth
disdista-1
Ekfrzoumeìle ti qronikmetaballìmene posìthte sto pedo twn suqnot twn, jewr¸nta qronik exrthsht morf
e
+jωt
. 2Praktik,ènaprìblhmamporenajewrhjedisdistatoanìle oiidiìthte twnmèswn poutoapoteloÔnparamènounstajerè kattonxona
z
giaarketm khkÔmato .th omogen exswsh toÔ
Helmholtz
:∇
2
xy
E
z
(ρ, ω) + k
2
(ρ, ω)E
z
(ρ, ω) = 0
(2.1)ìpou
k(ρ, ω) = ω
p
˙ε(ρ, ω)µ
0
h migadik stajerdidosh˙ε(ρ, ω) = ε(ρ, ω)
− j
σ(ρ, ω)
ω
h migadik hlektrik epidektikìthta∇
2
xy
=
∂
2
∂x
2
+
∂
2
∂y
2
h disdistathlaplasian.
Sto upì exètash prìblhma, jewroÔme dÔo hmipeira mèsa ta opoa qwr-zontaiapìènapl jo strwmtwnpeperasmènoupqou . StoSq ma2.1 blè-poumemiadisdistathtom t gewmetra . 'OlatamèsajewroÔntaiomogen , meexareshtoteleutao,stoeswterikì toÔopooubrsketaioanomoiogen q¸ro
D
d
. MporoÔmenagryoume:k(ρ, ω) =
(
k
i
(ω)
ρ
∈ D
i
i = 1, . . . , N
L
k
d
(ρ, ω) ρ
∈ D
d
(2.2)
kaiomow gia ta
˙ε(ρ, ω), ε(ρ, ω)
kaiσ(ρ, ω)
.Me bsh thn parapnw gewmetra, jewroÔme probl mata hlektromagnh-tik skèdash ìpou to prosppton pedo proèrqetai apì to mèso
D
1
kai o q¸roD
d
apoteletoskedast .2.1.2 Oloklhrwtikè anaparastsei
Giagrammikmèsa,toolikìhlektrikìpedomporenagrafew jroisma toÔprospptonto kaitoÔ skedazìmenoupedou,
E
z
= E
z
(i)
+ E
z
(s)
(2.3)ìpoutìsotoprospptonpedo
E
(i)
ìsokaitoskedazìmeno
E
(s)
ikanopoioÔn thn exswsh (2.1).
3
Qrhsimopoi¸nta to je¸rhma toÔ
Green
, mporoÔme na dexoume ìti to olikì kai to skedazìmeno pedo se kje shmeo toÔ q¸rou dnontai apì ti3
Oioriakè sunj ke ti opoe ikanopoietohlektrikìpedo parousizontaisto ke-flaio4.
x
y
D
1
D
2
D
N
L
−1
D
N
L
D
d
h
2
h
N
L
−1
Sq ma 2.1: Gewmetrapollapl¸n strwmtwndisdistatou probl mato .
oloklhrwtikè anaparastsei :
E
z
(ρ, ω) = E
z
(i)
(ρ, ω)+
Z Z
D
d
k
2
0
(ω)C(ρ, ω)E
z
(ρ
′
, ω)G(ρ, ρ
′
, ω) dρ
′
, ρ
∈ R
2
(2.4)E
z
(s)
(ρ, ω) =
Z Z
D
d
k
0
2
(ω)C(ρ
′
, ω)E
z
(ρ
′
, ω)G(ρ, ρ
′
, ω) dρ
′
, ρ
∈ R
2
(2.5) ìpousumbolzoumemeC(ρ, ω) =
˙ε
d
(ρ, ω)
− ˙ε
N
L
(ω)
ε
0
=
ε
d
(ρ, ω)
− ε
N
L
(ω)
ε
0
− j
σ
d
(ρ, ω)
− σ
N
L
(ω)
ωε
0
(2.6) thn antjesh t migadik dihlektrik stajer metaxÔ toÔ skedast kai toÔ mèsou pou ton perikleei, mek
0
(ω) = ω√ε
0
µ
0
th stajer didosh sto kenì, kai meε
0
, µ
0
thn hlektrik epidektikìthta kai magnhtik diape-ratìthta toÔ kenoÔ, antstoiqa. Gia lìgou sÔgkrish twn (2.4) kai (2.5) me enallaktikè morfè oloklhrwtik¸n anaparastsewn, shmei¸noume ìtik
2
0
(ω)C(ρ, ω) = k
2
(ρ, ω)
− k
N
2
L
(ω)
.Sti sqèsei (2.4),(2.5)sumbolzoumeme
G(ρ, ρ
′
, ω)
thsunrthshGreen
toÔ probl mato apousatoÔ q¸rouD
d
. H sunrthshaut epalhjeÔei thn exswshHelmholtz
meshmeiak phg stoshmeoρ
′
:∇
2
xy
G(ρ, ρ
′
, ω) + k
2
h
(ρ, ω)G(ρ, ρ
′
, ω) =
−δ(ρ − ρ
′
)
(2.7) ìpouk
h
(ρ, ω) =
(
k
i
(ω)
ρ
∈ D
i
i = 1, . . . , N
L
k
N
L
(ω) ρ
∈ D
d
enai h migadik stajer didosh toÔ antstoiqou probl mato me omogen q¸ro
D
N
L
.An sth sqèsh (2.4) periorsoume to shmeo parat rhsh sto eswterikì toÔskedast
D
d
,prokÔpteih paraktw exswsh:E
z
(ρ, ω) = E
z
(i)
(ρ, ω) +
Z Z
D
d
k
2
0
(ω)C(ρ
′
, ω)E
z
(ρ
′
, ω)G(ρ, ρ
′
, ω) dρ
′
ρ
∈ D
d
.
(2.8) Prìkeitaigiamiaoloklhrwtik exswshFredholm
deÔterouedou ,kaj¸ ognwstoE
z
emfanzetaitìso mèsaìsokai èxwapì toolokl rwma. 2.1.3 Mèjodo Rop¸nH oloklhrwtik exswsh (2.8) epilÔetai arijmhtik me th Mèjodo twn Rop¸n
(Harrington, 1968)
. Grfoumeth (2.8) se morf telest¸nw :L(f) = g
(2.9) ìpou:f = E
z
(ρ, ω)
g = E
z
(i)
(ρ, ω)
L = I − L
′
I
omonadiao telestL
′
=
Z Z
D
d
k
2
0
(ω)C(ρ
′
, ω)G(ρ, ρ
′
, ω) dρ
′
, ρ
∈ D
d
.
Apì ed¸kai sto ex jewroÔmeìti o q¸ro
D
d
èqei sq ma orjog¸niou parallhlìgrammoukaitondiakritopoioÔmeseN
C
= N
x
N
y
orjog¸nie kuyè-le , diastsewn∆
x
× ∆
y
h kajema. Sumbolzoume meS
n
thn epifneiat kuyèlhn
,kaimeρ
Epilègoume gia sunart sei bsh t mejìdou twn rop¸n ti sunart -seis-dekth:
f
n
(ρ) =
(
1 ρ
∈ S
n
0 ρ /
∈ S
n
(2.10) proseggzonta me autìntontrìpoti idiìthte toÔskedast kaj¸ kaito hlektrikìpedosto eswterikìautoÔmekat tm mata stajerè sunart sei .Oisunart sei probol pouqrhsimopoioÔme enaikatanomè dèlta:
g
m
(ρ) = δ(ρ
− ρ
m
).
(2.11)AnaptÔssoume th sunrthsh
f
sthbshf
m
,grfonta :f = E
z
(ρ, ω) =
N
C
X
n=1
a
n
f
n
(ρ)
(2.12)apìpouprokÔptei eÔkolaìti
a
n
= E
z
(ρ
n
, ω)
.Eisgoume thn parapnw sqèsh sth (2.9) kai problloume ta dÔo mèlh th sti sunart sei
g
m
. ProkÔpteitìtetoparaktwgrammikìsÔsthmaN
C
exis¸sewn me isrijmou agn¸stou , ti timè toÔ olikoÔ pedousto kèntro kjekuyèlh toÔskedast :N
C
X
n=1
δ
m,n
− k
2
0
(ω)C(ρ
n
, ω)G
O
m,n
E
z
(ρ
n
, ω) = E
z
(i)
(ρ
m
, ω) , m = 1, . . . , N
(2.13) ìpouδ
m,n
=
(
1 m = n
0 m
6= n
kaiG
O
m,n
enai toolokl rwma skedast -skedast t sunrthshGreen
,toopoodnetaiapìth sqèsh:G
O
m,n
=
Z Z
S
n
G(ρ
m
, ρ
′
, ω) dρ
′
, ρ
m
∈ D
d
.
(2.14)Gnwrzonta toolikìpedostoeswterikìtoÔskedast
D
d
mporoÔmena upologsoumetoskedazìmenopedoèxwapìautìn. AntikajistoÔmeth(2.12) sth (2.5) jewr¸nta ìtiC(ρ, ω) = C(ρ
n
, ω)
sto eswterikì t kuyèlhn
kaiparnoumethn paraktwsqèsh:E
z
(s)
(ρ
m
, ω) =
N
C
X
n=1
k
2
0
(ω)C(ρ
n
, ω)G
R
m,n
E
z
(ρ
n
, ω) , ρ
m
∈ D
/
d
(2.15)17
ìpou
G
R
m,n
enai to olokl rwma skedast -dèkth t sunrthshGreen
, to opoodnetaiapìth sqèsh:G
R
m,n
=
Z Z
S
n
G(ρ
m
, ρ
′
, ω) dρ
′
, ρ
m
∈ D
/
d
.
(2.16)Oi
Chommeloux (1987)
kaiDourthe (1997)
dnounthn analutik èkfra-sh t sunrthshG(ρ, ρ
′
, ω)
kai twn oloklhrwmtwnG
O
m,n
kaiG
R
m,n
ìtan uprqei mìno èna str¸ma metaxÔ twn hmipeirwn mèswn toÔ Sq mato 2.1 (perptwshN
L
= 3
).2.1.4 Exis¸sei pinkwn
JewroÔmeìtistoq¸ro
D
1
uprqounN
M
shmeamètrhsh kaiN
S
shmea ekpomp4
. Se kje shmeo metrme to skedazìmeno pedo gia èna pl jo
N
F
suqnot twn kai gia kajèna apì taN
S
prospptonta kÔmata. Gia mia sugkekrimènh suqnìthta kaiekpomp , orzoume ta paraktw dianÔsmata pou perièqountimè megej¸nstoeswterikìtoÔskedastD
d
:e
=
{E
z
(ρ
n
, ω)
}
e
(i)
=
n
E
z
(i)
(ρ
n
, ω)
o
ρ
n
∈ D
d
n = 1, . . . , N
C
kaiepsh todinusma
e
(s)
pouperièqeitimè apìtoq¸ro
D
1
:e
(s)
=
n
E
(s)
z
(ρ
m
, ω)
o
ρ
m
∈ D
1
m = 1, . . . , N
M
.
Me bsh ta parapnw dianÔsmata,mporoÔme nakataskeusoume tou p-nake : olikoÔpedou
E
(N
C
× N
S
)
prospptonto pedouE
(i)
(N
C
× N
S
)
skedazìmenoupedouE
(s)
(N
M
× N
S
)
twnopownkjest lh perièqeitodinusma mia ekpomp . 4
Oi
N
C
timè t antjesh mporoÔn nagrafoÔnse morf dianÔsmato :c
=
{C(ρ
n
, ω)
}
ρ
n
∈ D
d
n = 1, . . . , N
C
apìtoopooprokÔptei odiag¸nio pnaka :
C
= diag(c) (N
C
× N
C
).
Ta oloklhr¸mata
G
O
m,n
kaiG
R
m,n
exart¸ntai apokleistik apì th gew-metra toÔ probl mato . Oi timè tou mporoÔn na grafoÔn sth morf twn pinkwn: skedast -skedastG
O
=
G
O
m,n
(N
C
× N
C
)
skedast -dèkthG
R
=
G
R
m,n
(N
M
× N
C
).
Oiexis¸sei (2.13)kai(2.15)mporoÔnt¸ranagrafoÔnsemorf pinkwn. Gia kjesuqnìthtakaiekpomp xeqwristèqoume:
e
(i)
= (I
N
C
− G
O
C)e
(2.17aþ)
e
(s)
= G
R
Ce
(2.17bþ)en¸anproumeupìyhìle ti ekpompè maz, giakjesuqnìthta isqÔei:
E
(i)
= (I
N
C
− G
O
C)E
(2.18aþ)E
(s)
= G
R
CE
(2.18bþ) ìpouI
N
C
omonadiaoN
C
× N
C
pnaka . An upojèsoume ìti opnaka(I
N
C
− G
O
C)
enaiantistrèyimo , mporoÔme na gryoume to skedazìmenopedosunart sei toÔprospptonto pedoukai twnhlektromagnhtik¸nidiot twntoÔprobl mato :
e
(s)
= G
R
C(I
N
C
− G
O
C)
−1
e
(i)
(2.19)E
(s)
= G
R
C(I
N
C
− G
O
C)
−1
E
(i)
.
(2.20) Oi parapnw exis¸sei apoteloÔn th lÔsh toÔ eujèo probl mato skè-dash giamia sugkekrimènhsuqnìthtaω
. Apìtonorismì(2.6)prokÔpteiìti opnakaC
mpore nagrafesth morf :C
= diag(ε
r
(ω))
− j
diag(σ(ω))
ωε
0
−
ε
N
L
(ω)
ε
0
− j
σ
N
L
(ω)
ωε
0
I
N
C
(2.21) ìpouε
r
(ω) =
ε(ω)
ε
0
,kai
ε, σ
tadianÔsmata twntim¸n t hlektrik epidekti-kìthta kait agwgimìthta stiN
C
kuyèle toÔskedast .2.2 Antstrofo prìblhma skèdash 2.2.1 Orismì
To prìblhma pou exetzoume ed¸enaih eÔresh twn hlektromagnhtik¸n idiot twn toÔ skedast
D
d
me bsh to prosppton pedo, ti idiìthte twn mèswn poutonperibllounkaitoskedazìmenoapìautìnpedo.5 Oignwstè posìthte enai:
oiidiìthte twn
N
L
mèswn toÔ Sq mato 2.1˙ε
i
(i = 1, . . . , N
L
) , h
i
(i = 2, . . . , N
L
− 1)
oijèsei twn
N
C
kuyel¸ntoÔ q¸rouD
d
oijèsei twn
N
M
shmewnmètrhsh stoq¸roD
1
;sumbolzoumemeL
M
tosÔnoloaut¸n twnshmewnto prosppton pedosta kèntratwn
N
C
kuyel¸n, gia kajemi apì tiN
F
suqnìthte kaiN
S
ekpompèe
(i)
f,s
E
(i)
f
(f = 1, . . . , N
F
, s = 1, . . . , N
S
)
toskedazìmenopedosta
N
M
shmeamètrhsh ,giakajemi apìtiN
F
suqnìthte kaiN
S
ekpompèe
(s)
f,s
E
(s)
f
(f = 1, . . . , N
F
, s = 1, . . . , N
S
)
kaioizhtoÔmene posìthte enaioitimè t epidektikìthta kai t agwgi-mìthta kjekuyèlh .
JewroÔme ìti o skedast enai mèso qwr diaspor; s aut thn pe-rptwsh oi idiìthtè tou enai anexrthte t suqnìthta . 'Etsi mporoÔme na grfoume gia ton pnaka t antjesh
C
(ε
r
,σ
) paraleponta th mh ek-pefrasmènh exrthsh apì th suqnìthta. An epiplèon orsoume to dinusmaχ = ε
r
T
σ
T
T
pou perilambnei ti
2N
C
timè dihlektrik stajer kai agwgimìthta ,mporoÔme nagryoumeC
(χ
).Gia na broÔme to dinusma
χ
pou epalhjeÔei thn exswsh (2.19), qrh-simopoioÔme mia epanalhptik mèjodo. Xekin¸nta apì mia arqik timχ
0
, dhmiourgoÔmemia akolouja dianusmtwn hlektrik¸n paramètrwn, me stìqo na broÔme ti idiìthte tou skedast ekenou pou dnei to dio skedazìmeno pedometon gnwstoskedast .
5
To antstrofo prìblhma eÔresh twn idiot twn twn
N
L
mèswn toÔ Sq mato 2.1 qwr toskedastD
d
,èqeimelethjeapìtouAliferis et al. (2000b)
giathn perptwsh akoustik¸nkumtwn.Kataskeuzoume èna sunarthsioeidè pou metrth diafor anmesasto skedazìmeno pedo anafor to opoo prokÔptei apì ton gnwsto skeda-st kaistoskedazìmenopedoapì toantikemenokje epanlhyh :
J(χ)
,
N
F
X
f =1
N
S
X
s=1
kr
f,s
(χ)
k
2
L
M
(2.22) ìpour
f,s
(χ) = e
(s)
f,s
− G
R
C(χ)
h
I
N
C
− G
O
C(χ)
i
−1
e
(i)
f,s
.
(2.23) Sumbolzoume mek·k
L
M
to mètro pou prokÔptei apì to eswterikì ginì-meno
h·, ·i
L
M
toÔq¸rou
L
2
(L
M
)
twnmigadik¸n sunart sewnoloklhr¸simou tetrag¸noustoL
M
. Sth suneq perptwsh,toeswterikì ginìmenodÔo su-nart sewndnetaiapì:hu, vi
L
M
=
Z
L
M
u(ρ)v
∗
(ρ) dρ
(2.24)en¸sthdiakrit perptwsh hparapnw sqèshgnetai:
hu, vi
L
M
=
N
M
X
m=1
u(ρ
m
)v
∗
(ρ
m
)
(2.25)ìpouqrhsimopoioÔme tosumbolismì
z
∗
giatosuzug migadikìtoÔz
.To sunarthsioeidè (2.22) èqei mh grammik exrthsh apì th metablht
χ
. H elaqistopohs tou ja d¸sei th lÔsh toÔ antstrofou probl mato , dhlad todinusmaχ
poupargeitokontinìteroskedazìmenopedow pro topedoanafor .2.2.2 Mèjodo suzug¸n klsewn
Efarzìzoume th mh grammik mèjodo twn suzug¸n klsewn me thn pa-rallag
Polak-Ribi`ere
gia thn elaqistopohsh t (2.22). H akolouja twn dianusmtwnχ
k
(k
≥ 0)
kataskeuzetai sÔmfwname taparaktw:
χ
k+1
= χ
k
+ α
k
η
k
(2.26)ìpou:
η
k
=
(
g
0
k = 0
g
k
+ β
k
η
k−1
k
≥ 1
(2.27)g
k
= ∇J(χ
k
)
(2.28)α
k
:
∂
∂α
k
J(χ
k+1
) = 0
(2.29)β
k
=
g
k
, g
k
− g
k−1
D
d
g
k−1
2
D
d
.
(2.30)Apì th morf mplok toÔdianÔsmato
χ = ε
r
T
σ
T
T
prokÔptei ìti:g
k
= ∇J(χ
k
) =
[∇
ε
r
J(χ
k
)]
T
[∇
σ
J(χ
k
)]
T
T
,
g
k
ε
r
T
g
k
σ
T
T
.
(2.31) Qwrzoume to dinusmaη
k
sthn dia dom mplok,
η = η
ε
r
T
η
σ
T
T
kai orzoume:d
k
= η
ε
k
r
− j
1
ωε
0
η
σ
k
(2.32)A
k
=
h
I
N
C
− G
O
C(χ
k
)
i
−1
.
(2.33) H klsh toÔ sunarthsioeidoÔ (2.22) upologzetai apì th sqèsh (2.31), ìpou(Dourthe, 1997)
:g
k
ε
r
=
−2
N
F
X
f =1
N
S
X
s=1
Re
diag(A
k
e
(i)
f,s
)
∗
A
k
∗
G
R
†
r
f,s
(χ
k
)
g
k
σ
=
−2
1
ωε
0
N
F
X
f =1
N
S
X
s=1
Im
diag(A
k
e
(i)
f,s
)
∗
A
k
∗
G
R
†
r
f,s
(χ
k
)
en¸osuntelestα
k
dnetaiapì:α
k
=
P
N
F
f =1
P
N
S
s=1
Re
D
r
f,s
(χ
k
), G
R
A
kT
diag(A
k
e
(i)
f,s
)d
k
E
L
M
G
R
A
kT
diag(A
k
e
(i)
f,s
)d
k
2
L
M
.
Upenjumzoume ìti sumbolzoume me
A
†
ton ermitianì suzug toÔ pnaka
A
,oopoo isoÔtai me tosuzug migadikì toÔA
T
. GiatonupologismìtoÔsuntelest
β
k
,sqèsh(2.30),shmei¸noumeìtiapì thdom toÔdianÔsmato