By Anatoly RODIONOV, Dr. Sc. (Tech.), Stanislav SMIRNOV, Cand. Sc. (Phys. & Math.), Gennady YAKOVLEV, Cand. Sc. (Tech.), Central Scientific-Research Institute MORFIZPRIBOR

Hydroacoustic, or sonar signals to use another term, can propagate over great distances in the marine media, being reflected by heterogenous layers of seawater and boundaries, or interfaces involved in this process are "water-air", "water-seabed", "water-ice". All of these phenomena provide the basis of the principle of operation of different technical devices which are widely used on undersea apparatuses and submarines, surface vessels and also on what we call stationary and positional systems of monitoring used by the navies of different countries.

The birthplace of hydroacous-tics in this country in particular was its "Northern Capital"- St. Petersburg, and its history can be divided into several stages. In 18th- 19th centuries an outstanding scientist and Member of the St. Petersburg Academy L. Eiler, who was later succeeded by Professor F. Petrushevsky, Chairman of the Russian Physics Society, made the first steps in studies of acoustic fields in the air and in water. They established the phenomenon of refraction of waves in media with heterogenous temperature and also when crossing the "water-air" border. But it was only in the first third of the 20th century that research was started into the methods and devices for the registration of acoustic signals in water media and identification of the promising areas of application of hydroacoustic, or sonar, devices. And it was only in the Soviet years that the recognition of the practical importance of sonar research for the needs of our developing shipbuilding made it necessary to involve in this R&D work different industrial plants, colleges, scientific and naval centers and orga-

Pages. 67

Problems solved by the hydroacoustic gear of a submarine.

Pages. 68

nizations in what was then Leningrad (Baltiysky Plant, the KOMINTERN Plant, the Special Technical Bureau, Central Radiolaboratory, Electrotechnical Institute named after V. Ulyanov (Lenin), Physico-Technical Laboratory, Hydrography Department of the Navy, the Naval Military Academy, Scientific-Research Institute of Communications, etc.). Studies into the principles and methods of application of hydroacoustic devices were conducted by future members of the Academy, including N. Andreev, A. Berg, A. Joffe, L. Mendelshtam and V. Mitkevich.

A major landmark in the development of the branch was the establishment in our "Northern Capital" in 1932 of the VODTRANSPRIBOR Plant-a pioneer of our instrument engineering which manufactured sonars for Soviet subs and surface vessels, equipment for underwater sonic communication and echo-ranging sonars. The most effective among them was TAMIR-1 designed by E. Aladyshkin. During the Great Patriotic War it helped our Navy to timely and accurately target and destroy Nazi warships.

In recent years our scientists and engineers started work on sonar units with an effective range of tens and hundreds of kilometers. The main centers involved on the project include, above all, the Scientific-Research Institute of Hydrolocation of the former USSR MINSUDPROM (Ministry of Shipbuilding) which is now the Central Scientific-Research Institute MORFIZPRIBOR. Within a short range of time its "products" were installed on the Russian nuclear missile fleet with an unlimited autonomous range of operations.

In the middle of the 20th century the governing factor in the development of hydroacoustics was the discovery of the undersea sonic channel and remote "zones of illumination" in the ocean. It turned out that because of defraction (deformation of rays trajectory) acoustic waves from underwater sources can propagate over considerable distances in the undersea sound channel without contacting either the sea surface or the seabed. This provided the basis for increasing considerably the effective range of echo-ranging sonars.

The complexity of development of multifunctional sonar systems that can meet the stringent requirements of the Navy made it necessary to set up a number of new research centers. Among them have been the Institute of Acoustics (now named after Acad. N. Andreyev)-the leading R&D center of its kind, the Kiev Scientific-Research Institute of Hydro-Instrumentation, which specializes in sonars

Pages. 69

for surface vessels, the RIF Scientific-Research Institute (Beltsy, Moldavian Republic)-navigational sonars, ATOLL Scientific-Research Institute (Dubna, Moscow Region)-stationary sonars, BRIZ Scientific-Research Institute (Taganrog)-mine detectors, SHTIL Scientific-Research Institute (Volgograd)-hydroacoustic communication, BEREG Scientific-Research Institute (Vladivostok)-positioning sonars. Each of these centers has provided tangible contributions to strengthening this country's defense potential.

In the latter half of the 20th century a total of 138 sonar systems were designed and built for the needs of the Russian Navy and 105 of these systems were produced by St. Petersburg scientists and engineers, mainly from the MORFIZPRIBOR Center. As a result, our subs and deep-sea probes, surface vessels and naval aircraft received what we call multi-functional hydroacoustic complexes and specialized stations. Apart from ship-borne equipment, stationary systems have been developed which provide for the early detection of enemy subs and surface vessels in areas of the ocean which are of strategic importance for our national security. Much credit in this respect belongs to the chief designers of such stations- E. Aladyshkin and V. Borodin.

Over the years a powerful R&D potential in the field of hydroacoustics has been formed in our Northern Capital. In the mid-1980s the staff of the MORFIZPRIBOR alone had more than 7.5 thousand specialists, including some 250 doctors and candidates of science whose works helped establish whole schools of research in antenna technology systems of monitoring sea conditions, navigational and sonar search, or asdic, systems. Used on the project was the Europe's biggest test basin equipped with acoustic damping and measuring 50xl4x10m in size. The Ladoga testing site was fitted out with special floating labs and research vessels as well as the matching on-shore structures. Operating at the Institute was a stand for the modeling of algorithms and adjustment of soft-wear for hydroacoustic systems, which boasted unique parameters and "filling". The RUBIN Central Design Bureau (located in our city) developed specially for the MORFIZPRIBOR the submarine laboratory AKSON equipped with the most up-to-date measuring-and-coordination device with an areal of 50 m for precision measurements of antenna parameters.

As a result of all these efforts our domestic R&D centers have attained world level by all of the main tactico-technical parameters.

Today Russian hydroacoustic complexes, if one regards them as digital data systems, boast some really unique characteristics: the number of input channels of up to 10 ⁴ , data flux at the input of digital computer center-10 ² Mbyte/s, output capacity -10 ² Gflops, softwear volume-up to 5 Mwords. At the same time, there is some lagging behind from the international standards in the quality of our "home-made" computer gear which creates some problems with the introduction of modern algorithms of analysis and data assessment and puts some restraints on our designers. Drawbacks of this kind are made up for by a much higher level of antenna technology than that in other countries, a greater depth of studies of the marine environment and the development of what we call economic algorithms, approaching the optimal.

Illustrations provided by the authors.

Permanent link to this publication: