Page 236 - 《应用声学》2024年第1期

232 2024 年 1 月

RX A
160 mm ቇ

t t f ඡ B
1. Time data p↼x֒y֒t↽ → 2. Time mirror p↼x֒y֒֓t↽ → 3. DFT p↼x֒y֒f↽ C1
C2 Ꭵᬞ
ሏஙϬ᧗Ձԫ૱ Ѭ࣋

200 mm ెந
t t f
6. Time mirror p↼x֒y֒z֒t↽ ← 5. IDFT p↼x֒y֒z֒֓t↽ ← 4. Re
rad. p↼x֒y֒z֒f↽ TX

(b) ௑ᫎԦᣁೝ฾ [46]

ԠᏦηՂ

Ӝᦡ Ԧ࠵ฉ
໚ฉ٨ ࠵ฉᣁ૱ ᫠ϙ ᣁ૱
ଌஆηՂ ԍ᎖ηՂ ࠵ฉጇ஝ ࣨϙጇ஝ ᣥѣηՂ
(௑۫) (௑۫) (௑۫)
(c) ᑢфԍ᎖ˁ࠵ฉ໚ฉຉՌܫေ [45]
(1) (2)
(1) ᘙ౜ೝ฾࣢
᜻Lambฉ௑ᫎ
æ A to B ŀ A to B Ԧᣁᇨਓڏ
ç ൈࡗّሇ (3) Рݻฉੳଡ
ᫎԦᣁካข
A B A B (2) ʷመξ൤௑
è B to A ł A to B ˁ ۳ ̆ ᘿ લ ௑
ᫎ Ԧ ᣁ ᄊ ഐ ဋ
ੇ ϸ ካ ข Ѭ ࡏ
Ł ௑ᫎԦᣁ
ೝ฾
(3)
f A1 (ω) f B1(ω)
æ A to B
f B1 (ω)
⇀
Ł ௑ᫎԦᣁηՂ: f B2 (ω)=f B1 (ω)
A B f A1 (ω)
(d) lambฉੳଡˁഐဋੇϸካขᄱፇՌ [47]

X-Y ੳଡ ҒᎶஊܸ٨ ηՂԧၷ٨
PIZEO Tektronix
ԧ࠱ଊ݀ ጳভஊܸ٨ AFG 3022C

ଌஆ
ଊ݀ X-Y ൦ᤉ଍҄٨

+200 V ηՂஊܸ٨
ᄰื CA6/C ˟఻

Tektronix
NCA1000
ᣁ૱٨ TDS540
UPCጇፒ
஝ߚᇨฉ٨ ᇨฉ٨ ஊܸ٨
(e) ᑢфԍ᎖ᡔܦੇϸࠄᰎ࣋Ꮆ [49] (f) ᄱͯᎄᆊ༏ҵ֗ᑢфԍ᎖੿షऄၹ̆ቇඡᏹՌᡔܦೝ฾ࠄᰎ࣋Ꮆ [49]
图 12 信号处理方法
Fig. 12 Signal processing method