(SANITIZED)SOVIET ACOUSTICS(SANITIZED)

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00926A008400320001-8
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 43
• Document Creation Date: December 20, 2016
• Document Release Date: January 25, 2008
• Sequence Number: 1
• Publication Date: March 1, 1956
• Content Type: REPORT

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0 -C-x-Y-I-D-E?s'-T-ice
INFORMATION REPORT
This material contains inform
formation
affecting the
National Defense of the United
States
within the
2
meaning of the Espionage Laws
Title 18
U
S
C
PREPARED AND DISSEMINATED BY
,
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Secs.
. 793 and 794, the transmission or revelation
INTELLIGENCE AGENCY
of which in any manner to an unauthorised
Per
son is prohibited by law
COUNTRY yVec
SUBJECT Soviet
DATE DISTRIBUTED
tair> s era
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THIS IS UNEVALUATED INFORMATION
Title Of Parer
L X Brekhovekikh Acoustical Institute of
Focueing of Sound Waves in
AS, BS , Moscow
Inhomogeneous Media
Yu P sanovg Acoustical Institute of AS$,
An Approximate Solution of
USSR,, Moscow
a Problem of Bound
Scatter.i
p
tug from Rough Surfaces.
Bound Scattering from Plane
Inhomogeneous Surfaces with
Acoustic Admittance Changing
Periodically along the Sur-
facee
L D Rose } Acoustical Institute of
Tech of Destruction of
A B Beb htsuk ) AS p S.g Moscow
Solid Surface Films by
X 0 )
Acoustically Induced Cavitau
tion.
B D Tartetkavsk~r,. Acoustical Institute of
Filters and
Matching Layers for
AS, USSR., scow
ultrasound.
o
I N ran ) A oustical Institute' . of`
Diffraction Patters Near the
L B Rosenb.g) AS, USSR, Meacowil
Focal Line of a Converging
'Tu L r sn$ Aaausticel Institute of
~"
Cylindrical tv.
On 'W aveguide Propagation in
SSR
Maser
I1l~hl Igeneous Media
~,
DISTRIBUTION
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A
N A Iseekovite h9 Acoustical Institute of
AS9USSR9 Moscow
A N dye Acoustical Institute
A89 USSR9 )W cow
A V Rimskr4 kov, Acoustical Institute
of AS9 USSR9 Moscow
A N Bares v0 Gorlkiy Sam-
(Signature Illegible)
University (7)
M I Ksr Central Research Insti,tutep
Leningrad
I G Mid v , Leningrad State University
V ll' Nozdrev Moscow State University
V D Soboley
A M Suitanov )
U R Bormosov
V F Nozdrev9 Moscow State University
Marine Hydrophy s ice Inat o
Academy of Sciences.
M L Levine D Sep Ivanovo Pedagogical
Title of Kq~r
The Application of Solid Layers
for the Removing of Shear Waves
Appearing at the Reflection of Sound
Waves from the Boundary of a
Solid,
The Use of Rirchgoff Vs Principle
in the Solution of Seca Pro Ieasss:
Relating to Scattering and Radia.
tion of Sound,
Investigation of the Scattering
of Sound Waves on Corrugated
Surfaces o
Audibility of nlinear Distor-
tion in Sound Transmission Sys-
tems.
Experimental Investigations of
Sce a Cases of Sound Propagation
in a Stratified- Inhom ogeneous
Medium,
S< Theatical Considerations
on the Flexural Vibrations of
Plates and the Associated Radia-
tion of Bound
Calculation of Strong
Velocity of Bound in Pure
Liquids and Liquid Niaetures.
The Differential Method of
Measuring Ultrasonic Absorption
in Li.,quidso
Ultrasonic Absorption in Viscous
Liquids
Experimutal Investigation of
Relaxation 7 ocesses Arising
When Ultrasonic Waves Pass Through
Liquids o
Investigation of Acoustic Pro.
perties of Organic Substances
in the Critical Region
Some Results of the Analysis of
Singing Voice
On the Transition to the Geome-
trical Approximation in the
Theory of Elasticity.
Institute )
S M Rytove U Sag P R Zebedev Physical Insti
tote of the Academy of Sciences )
of the USSR. )
LIED
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Etho
-'
S M Rytovp DSc P N lebedev
Institute of the Aktihd,amX
Sci,eem of' the MR
Pzvf lac Che xs~ D D S ;O He-ad ? f the
la i r In tout '.
S
a v,
V P Yskov,
V D sobolev
V ? N
N I ss'in
V A XzAaDm1k0v'acsoi der
.Am Aead of ien. eB
oiler-t3i?. a Vf
't ive Pop of Wave In
I mageteous d tm
Tq u. e e tbod of Fixed. D s` ?ee,
It si Pb i 1 his and P.'ac` VRI
~ Wave ? a ` i m i+ dia with
,ruler Flu,ytmatloux of the
a e 'iaeti.ve
9 Pavlov Institute of Physiology a hoait New Methods o Ja ment
of the Accade y of 5 i ew* of Hest'rt g in am,
the 9ex~~.axsd
k ~t t c+ w I ,. ;4 ? a x i s "#':r ~' i s e .?q
I YP El Tlr r~.v r. 6A~,,rw
V A zVe ty'
lira, ~4 . Milt and for Moneu emente
Vii l DIS P2' .4`$ ?? .t
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-5-
"Diffraction of Sound at UneN en Surfaces "g by L X
Brekhovskikh,, kl0 Akan. Neves 9 585 (1951
"on a Special Foam of l ing in Wave Propagation in
miner Inbooogeneous l iedia"s by L X Brekhovskikh
and I I ov9 t; gusto Joux?to c SRs .p 23-30
2-9 (1955)e
tea, V. Gerehunis Pavlov Institute of Pbysiule-gy of the Aeeedasy of Sciences
of the USSR9 L,ningra 4
Technical Interests x Physiological e,couatics i mechanism and measure.
aunt of hearing; the electrical sti ation; effects of blast,
Invited to present a paper In the special session on big-scoust1.cs,
Contributed title and abstracts
"About New Methods of ,Measurement of Searing in Wes,
by G V aershuniQ
Publications include s
"On the Sensory and Subsensory leactions Evoked by Ecterral
Stimuli. Acting Upon the Human Sense Organs". by G V Gershuni,
Bull. Acad. Seim USSR (Biel, Sere) 2$ 210-228 (1945).
"Trransfornmltion of Auditory Function from the Effect of sound"
by G V Gershuni8 Trobl. Fiziol4 Akust, Moskva
i, 5-19 (109).0
"Physiological Principles of objective At4lometry"g by,
0 V Gershuni, Trobl. Fiziol. Akust. Moskv
=ZW a 2, 3-7 (1950).
"Quantitative Investigation ' of the Range of Action of
Imperceptible Sound Stimulations", by G V Gershunis dbl.
Fiziol. Akust0 I akvaa 2, 29-36 ti.95o).
V A lsilnikovf, Physics Research Institute., t e onosov State University of
Moscow
Technical Interests- Interaction of sound and turbulence; propagation
in the atmosphere.
Invited to give paper in special seessio* on Interaction of Sound with .
Turbulence : and Shock, under physical acoustics.
Contributed title and abta ctt,
"On Wave Propagation In Nadia with Irregular Fluctuations
of the Refractive Index" by V A Krasilnikov and A M Obukhov.
Publications include-.
"Some. Hew Experiments on the Propagation of Sound in the
Atmosphere", by V A I(rasilnikov and K M Ivaanov-Sita3 .
A d.. Nauk, ?1, 639 (1999).
"'Fluctuations in the Phase of Ultrasonic ~aves Propagated
in a layer of Air Near the Earth" g by V A ~ ;Srasilni kov,
Dokl. Akad. Sauk, 889 65 7 (1953).
I-D -E-R-T-I-A?L
NO DISSEN ABROAD LIKEM
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"Dispersion of in a Turbulent Plew" by V A
lissilnikov and V ,j Taterskii8 Desk],. Akad, AankD
s 159 (1953)0
X G Mikhailove Leningrad State University
Technical, interests Piezoelectric arystelss absbr~tion'and-velocity
of sound in liquids and liquid mixtuxess mechanical psoper-
.ties of polymerso
C'~ 1 ~Imm~E-N-Try-1 L
m6m
Invited to present paper in special session an sound absorption phend
mena under the general area of physical acoustics and conics.
Contributed titles and abstracts.*
"The Differential Method of Measuring Ultrasonic Absorption
in Liquids" by 1 0 Mikhailov
"Ultrasonic Absorption in Viscous Liquids" by I G`Mikhailov.
Publications include s
"Velocity of Ultrasonic Waves in Certain Binary Mixtures of
Organic Liquids"a by I G Mikhailov and A A Tsistorazum
Dcrkl0 Akad0 Nsuk,, 81
779 (1951).
"The Absorption of Ultrasonic Raves in Liquids and the
Molecular Mechanism of Bulk Viscosity"# by I G Mikhailov and
V A Salovev9 Usp0 Piz 0 Netuk, .,2 3-50 ' (1953)
"Propagation of Ultrasonic Waves in Polymer Solutions", by
I G Mikhailov and L A vo D?klm Akad0 Nauko ~ 829.
(1953)0
"The Absorption of Ultrasonic Waves in Binary Mixtures of
Liquids with One Relaxing Component" 9 by I G Michailov and
L I Sapp Dokl L Akad 0 uka SSSR$ 26P.1147 . W54)..
"Application of Composite Piezoelectric Vibrators to an
Investigation of the Mechanical Properties of Polymers",
by
I G Mikhailov and B A Solovev, Acsoust. Journal of USA :
343-347 (1955)0
Invited to present paper in a special session on sonies under physical
acoustice 0
"Mehanism of Destruction of Solid Surface Pilma by
Acoustically Induced Cavitation"e by L D Rosenberg, A S
Bebtchouk and L 0 Makarov.
L D Rosenberg., Acoustical Institute of A0 S. USSR,, Moscow
Technical Interests Transducers,, including focussing devices and
multiple source arrays y long-distance propagations cavitations
radiation properties in geneeralo "
"Diffraction Pattern Near t
Cylindrical Wave" by I N H"aneavsky a
NOFCHN NO DISSBM ABROAD
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P blisatims include s
"Sound Fields Formed by Distributed Systems of Radiators",,
by L D Rosenberg, Zhurnal Ta kbnlsheskai Fiziki 120 102, 220
Tekhfisheskoi Fiziki 12, 211 (191
?
"The Directional Properties of the Tar Carried Out on
a Dui y" by L D Rosenberg and B D Tartakovs ee
Rendus Doklaa ) de 1? des Sciences , 26 578 (194).
"Distributed Systems of Radiators Employed in Architectural
Acousticrs", by L D Rosenberg,, es Rendue LIMP
)ee
1'Aoadfl des Sciences USSR 31v 563 (1941 ?
"The Sound Field Obtained when Music is Reproduced by a
System of Distributed Radiators" b L D Rosenberg, l
2
P 1634 (1940)-
"The Effect of the Mean Coefficient of Bound Absorp-
tion on the .Level of Sound" by L D Rosenberg and A B
diaviau Part Y? Journal er1 Tochni!al PhysicfD .~
(1,912)0
"On the Distribution of Sound Absorbing Material in a Closed
Room" by L D Rosenberg, DAN SR, 21, 599 (19-46).
"An Experimental Investigation of Diffraction in the Focus
of a. Zone Plate" by A A aehevee, L D Rosenberg and
R D Tartakovskiy, C R Acad S,ni 395 (1917)o
"Sound Wedge and Homogeneous Sound Lens". by L D Rosenberg,
Journal of Technical Ph sies USSR 18, 11 (1918)
"A Rev Phenomenon in Hydroac rustics" by L D Rosenberg,
Dokl? Aked ? Rauk, SSSR , 175 (1919) a
"Development of Work o u Souni P ussing", by L Ti Rosenberg..
lzv? Aked? Rauk B Bev? Fiz?8 710 (1918)?
"On the Focussing of Sound Waves by a Parabolic Mirror" by
L D Rosenberg, J? Tech. Phip? USSR, 20, 385 (1950),
"Two-Mirror Concentration of Ultrasonic Waves" by L Ti Rosenberg,,
Dokl? Akad ? Rank SS BR 21,9 1091 (1953).
"Calculation of Amplification ;produced by Cylindrical Sound-
Focussing Systems" by L D Rosenberg, Akusticheskit Zh, 1, 70
(1955}? 25X1
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 Approved For Release 2008/01/25: CIA-RDP80-00926AO08400320001-8
L.M.Brekhovskikh.
Focusing of sound waves in inhomogeneous media.
The sound field from a point source in a stratified
inhomogeneoue medium is represented in an integral form
in terms of plane waves coefficients of reflection. At
sufficiently high frequencies coefficients of reflection
can be calculated by means of BWK method. Then the appli-
cation of the method of steepest descent gives the ray
approximation for the sound pressure. In developing this
theory equations of caustics were obtained and sound pres-.
sure near caustics and in the neighbourhood of a cusps of
caustics was determined. The development of the field. in
a sum of modes (1) did'nt appear necesssrv. Examples are
given. The theory of focusing action of stratified media
appears to be quite analogous to the theory of focusing
by optical systems when areerration is present.
(1 ) Haskell,N.A. J.Appl.Pnvs. , 22, 157-158, 1951.
Moscow.
Acoustical Institute of A. S. USSR.
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Yu. P.Lvsanov.
An approximate solution of a problem of sound scatte-
ring from rough surfaces.
A method is developed of calculating the scattered
sound field from a rough surface. The method is based on
the solution of an approximate integral equation for the
normal component of velocity on the surface.
The method is valid for pressure release surfaces.
When the amplitude of roughness is great as compared with
the wavelength of the incident radiation there is a more
rigid limit for the values of the slope.
For periodically rough 9uirfaces, satisfying the con-
ditions stated above, the scattered field is calculated
for both the infinite and finite rou-h surfaces.
Moscow.
Acoustical Institute of A.S. USSR.
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Th? P. Zysanov.
Sound scattering from Plane
inhomo eneous surfaces with
acoustic admittance ELnging in eriodicall
al on the sur_
A method is given for calculating the scattered sound
field from plane inhomogeneous surfaces having normal im-
pedance or admittance independent of the angle of incidenc
e.
The expression for the
scattered field is represented
in the form of power series of a
relative inhomogeneity of Parameter determining the
the surface. A recurrent expre-
ssion is given for the n - th term of the series. Severs
particular cases are considered in more detail. l
The proposed method is valid for any ratio
is the wavelength of the incident radia where
spatial period of inhomo~~eneit tlon and L the
y. A comparison is made with
the approximate solution obtained on the assumptin
the change of admittance is small at the distanceooftthe
the
order of one wavelength; it means that it is Possil
neglect diffraction effects in the immediate vicinity tf
the surface. A criterion ;~ o y of
~"j Vlle
approximate method. validity of this
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Moscow.
Acoustical Institute of A. S. USSR.
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A.S.Bebtchouk
and L? 0. Makarov.
Mechanism of destruction of
solid surface films b
acoustic all induced cavitation
The cavitatio
nal destruction of a thin lager of varnish
put on a glass plate
was studied by means of high speed
Photography at the rate of 2000 frames
riments were carried on per second
in an inactive Expe-
the frequency 8000 cps. It liquid (water) at
) at
of the film is c east found that the
aused at least b destruction
Primarily y two different f
actors,
it is observed as the result, of
bubble collapse in, the b1g cavitation
immediate observation of vicinity
such bubbl e of tie surface.
and complex forms of s Indicates 1ar,
vibration. e amplitudes
that the process itself It is important to
of bubble formation note
llations at the very surface and its
Y surface of the osci_
fluence on the film; film are without in-
in-
first but the bubble collapse 12000 sec, to destruction of p leads in the
a circle with the the film extending on
the bubble at the center coincidin
g with the position of
the bu n i moment of colla
s caused b Pse. Another t
y small bubbles YPe ?f des-
which quid with smooth surfaces
Y penetrate between
a destructed the film and the Slass defach des from spot' causing small irre ar bits of fil at
the surface. m to
Moscow.
Acoustical Institute o A.S. U
SSR.
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B.D.Tartakovsky.
Filters and matching layers for ultrasound.
Methods of acoustical. matching on the boundaries of
different media by means of matching layers are studied
theoretically and experimentally. Conditions are found
giving the least transmission loss in a wide frequency
band for a given number of layers. One and two-layered
elements made of different materials were tested experi-
mentally. The resulting matching of ultrasonic lenses and
prisms in the water increased the transmission coeffici-
ent to tr1e value of 98-999. The transmission coefficient
of a steel plate covered with matching layers reaches 90.
Interference filter composed from three layers exert a
wide band filtering action on inclined rays and correct
tr,e form of the wave-front.
Moscow.
Acoustical Institute of A. S. USSR.
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,L. N. Kanevsk
y and I,.D.Rosenberg
Diffraction pattern near the focal line of a corver-
ding cylindrical wave.
Assuming the small value of the ratio of the wavelength
to the dimensions of the radiator, expressions are found
for prpssus'e and velocity distribution near the axis of a
convergent cylindrical wave front. For some concrete cases
(ceramical transducer with radial polarization, ceramical
transducer with axial polarization and a reflector'in the
form of a parabolic cylinder) focusing factors, gain and
width of focal strip for pressure and velocities are cal-
culated. A constant angular distribution of the amplitude
on the surface of the converging front gives maximum value
of the pressure focusing factor. In this case the follo-
wing expression gives the width Zo of the focal strip:
where K=?ir 2-
A and k ,,` is the aperture angle.
The approximate expression ?o~ = U,5/ ate is accu-
rate enough for the most practical Purposes. Corresponding
expressions for different other cases are obtained.
Finally some formulas are quoted connecting the pressure
on the axis with the focusing factor and total incident
energy. It is shown, that in the case of a finite length
of radiator, the obtained results are valid on the whole
length of the axis except small portions at the ends mea-
suring about
VA f where f is focal distance.
Moscow.
Acoustical Institute of A. S. USSR.
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Yu. L.L G s an.
On wave ids protiA
ation in inhomoNeneous media.
The representation in an integral form of the sour
field radiated by a Simple d
with point source in the medium
the velocity depth dependence according x)
is given. The case of to Epstein
detail. At long distances, the field is represented by a
sum of normal modes and a head-wave. There is
le dependence of a very simp_
eigenvalues on
The vertical field distribution of separate of the problem.
separate modes is gi-
ven by Jacobi
polinomial s. In the case of s-
in of velocities the Y~etrica.l dis
solution is obtained likewise
presence of a perfectl
axis of the wave y reflecting surface on the
guide. A comparison is made between the
e -Pct solution and the
approximate solution obtained by
the wKB method.
a
P. S?Epstein
Proc . Nat. Acad. Sc. USA. , 1930, 16P N10, F 27.
Moscow.
Acoustical Institute of A. S. USSR.
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M. A.Iasakovjtch.
T application of solid lagers for the removing of
shear waves appearix at the
from the boundar
of a solid.
At tvP incidence of a longitudinal Y" v9 on a rlane boun-
dary of " solid, covered with a layer of another solid sub-
stance rijidly fixed to the former, the reflected ever j is
divided between a longitudinal wave and a shear wave.
Theo amplitude of the latter depends on the density and
elastic , properties of materials, on the thickness of the
layer and on the angle of incidence.
Forr different comhinations of materials and for different
wles of incidence, the thickness of layers is computed ?:i_
vine.; zero amplitude of the reflected shear wive.
In this case the longitudinal wave is reflected totally
and no transformation into shear wave occurs.
Moscow.
Acoustical Institute of A.S. USSR.
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The use of Kirchgoff's prir:ci_~?ip i_r. + e X01 A'
problems relating to sc-Fit ring; ?nl rarl~i
This is a study of some problems rP? =a.ti.n ' (,
tering by randomly inhomogeneous sur? es
at; on by randomly oscill.ating surface s. It i
goff's assumption) that the field ^c,i It of } r,~
-e is the same as if it were built hr to, a 1."n,,Pnt :,1-Y10
having the same nrorerties t trhi s -)int. In the
seatteri.ng this assumption t"tr'
field on a plane surfa.P' from the change of its. r>ro ert.ies
from point to point. In the radiation problem the bold in
any point of a curved surface is assumed to be eqiual to the
field that would. be built up by the tangent nlene with tae
same velocity distribution. The intensity of scattered or
radiated field in the Fraunhofer' s zone is expressed in terms
of correlation functions of normal velocities or parameters
of the surface.
..A.Issako"T?t( I.
Moscow.
Acoustical Institute of A. S. USSR.
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A. N.Le' o er
Inve s?i Zation of the scattering of sound ' C on
corrugated surfaces.
Experiments on the scattering of sound ~~'.tves b;r morjels
with -eriodicall `r corru6atei1 frontal sure-'aces are de9r r-7%-
bed. RAsults of ~P,a ,ar.ee~Fants are discussed and compared
with -xi_sting theories ;",2;. it is shown,
resolves into separ:,.te snectr'al. benirs at tnie 1is-
;=inc e R, ._-
71~.L r)i. , T' - length ni eorru,cr teC1 sur? ne
s 7,a 71 A
len tit o`' ]yloi-6pr
The angle
Of iYicir'enr'a, 190 an?i
~' .^7`r~snonriipcr ar1~-1es ~r~ of ?rectra of di-r'ferr- -
aL,r e within tue experimental error with t ieo.r'eti%'ai ex-
pre^sion:
+ r ,~ l
L
where VYl is the order of a particular spectrum. In the
regions of validity of mentioned theories, the agreement
between experimental and computed data for the relative
values of sound pressure amplitudes is satisfactory.
1. L.M.Brekhovskikh , Zhur.Eksptl. i Teort.Fiz., L, 1952.
2. Yu.P.Lysanov , Dissertation, 1955.
Moscow.
Acoustical Institute of A.S. USSR.
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A. V. Rim sky-Kors akov.
Audibility of non-linear distortion in sound trans-
mission systems.
The non-linearity to be allowed in sound transmission
siystemis usually found experimentally. For this purpose
a group of persons is proposed to find (by listening to
a program) the grade of non-linearity at which distortion
is noticeable. The resulting data may depend on the hea-
ring sharpness of these people, on the sequence of the
experiments, on the form of non-linearity, frequency band
and transmitted program. Therefore the value of such da-
t,,, is limited. Distortion hearing thresholds for various
programs and forms of non-linearity were measured. In a
single experiment for a group of people they are distri-
buted in a good agreement with the Gaussian law. A method
of computing the non-linear distortion audibility was de-
veloped. The transmitted signal is considered to be a sta-
tionary oscillating process with normal distribution law.
The probability for the non-linear products to exceed the
hearing threshold which is influenced by the main trans-
mitted signal (masked) was computed. Calculation for a.
constant amplitude spectrum signal and transmission sys-
tem with a frequency band 100-5000 cps. and various dis-
tortion factors was done. The probability of noticing se-
cond order non-linear products for a distortion factor =
3% was found to be 0,035; as for g distortion factor = 596
nearly 1/1/ of the whole
7 5 program may be spoiled by
non-linear effects.
Acoustical )nstitute of . S. USSR.
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 Approved For Release 2008/01/25: CIA-RDP80-00926AO08400320001-8
$perimental Investigations of Some Cases of Sound
Propagation in a Stratified - Inhomogeneous Medium.
B. N.Parkhatov
The proof and the description of the method of a laboratory
investigation of sound propagation in stratified-ir_homo-eneous
media are given in this article.
The method has been used for souna L.-.iensity measurements in
the medium wi to a come t, t negative gradient of the sound velocity
and in a similar medium with a surface quasi-isothermal layer.
There hcea beau made a cor'~p..xisoza between experimor'.4xl and
theoretical data, in particular, tnere is considered the
problem of the le, aiitS of appiy:iny the --eometric .L acoustics in
certain cases.
The interference picture has been shown to be observed in the
region nearest to the source in the medium with a constant nega-
tive gradient of the sound velocity, at an average the inverse
square dependence of intensity upon distance taking place.
The position of the extrena may be computed by means of the geo-
metrical acoustics, the difference between the experimental and
theoretical values increasing with the approach of the boundary
of the geometrical shadow. In the latter zone the measured values
of sound decay are in essential agreement with the wave theory (6,71
There have been made experiments on measuring sound decay in
the surface isothermal layer and in the lower lying inhomogeneous
medium with a constant negative gradient of the sound velocity
at different values of the parameter 1 101. It has been shown
that the sound field may be divided into two regions - the zone
of interference and the "effective shadow" zone.
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 Approved For Release 2008/01/25: CIA-RDP80-00926AO08400320001-8
In the latter zone the measured values of sound decay correspond
to the theoretical ones at a < 1 (10,11]. It has been found
that the boundary of the application of geometric:.-' theory when
the sound is propagatin, in a homogeneous surface layer may be
valued by means of ' rekhovskich' s theory [1 C. 3.
The described method may also be used for the it Yeati,~ations
of mound propagation in other stratified-irlhono,--ne) ..a ntdia.
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 Approved For Release 2008/01/25: CIA-RDP80-00926AO08400320001-8
A AR Jilicr m +Z3Fil m
Some theoretical considei?r.tions
0*1, the le;a direr
DO'4~~*_ (K, wave number;
angular fre ancy .
ieaarzrers*t of D is based on the transformation
modolalialt in smplitude modulation and vine-veraa, whet:
modulated sins wave travels through a dispersive ec2i
senaivity the method depends only on the noise ?ev4.,
receiver and it is independent of the Unavoidable s: ii
variations of the' sound velocity in the medium cndd r test.
The results at experiments on ultrasonic waves in thin
wires (l.mgitatal waves where *aed) and in water at I So/see
(modulaftes. fregmaasy t 100 Ic/ses) are given. The experiments
were &er It for determining the possibilities of the
relied in aaaasties., In the case of longitudal- waves in 4 this
wire the dispersion can he calculated from the tssry of
Blast tj, ?h. valor of D obtained experimentally is in
a good agreement with the ealcalated one. the relative change
of the pie velesity corresponding to the frMaency interval
of 1010 Ic,/sea was about I0,4., In water no dispersion was observed
that agrees whith the theory. L variation of velocity of I cc/see
in a fretumey. interval of 100 Lo/seo was detectable when the
reoeivew band was about I Li/sea. In order to prevent reflected
waves a optical. Indicator of a]?trasonis waves was used.