text: 131+. There are sea-based systens conprising acoustic detectors and arraysenplaced on the ocean bottom for roonitoring the passage of submarine forces, butnot much is publicly known about their perforaance. Hor^/ever, both the Sovietunion and the united stetes continue to build and operate sLBM subnarines; they wou-l-d. not do so if they were not confident of the continued survival of the sLBMsduring nuclear var. rntensive research continues on both sides to detect SI,BMsubmarines, but also to ensure that there is no capabirity avairable to the otherside which can imperil oners own SLBM ffeet. Non-acoustic techniques continue tobe studied" based on the disturbance of rnagnetie fields, hyaroaynaiic fielals andthe like, 135. Anti-subrnarine warfare_ (aSW) technology has advaJrced. increnentally, relyingprinarily on passive acoustic detection of the noise enitted by subnar-ines, vithfixed hyd-rophones on the ocea.n botton, on sonobuoys dropped. br aircraft, and onsonars nourted on or toved. by sulface ships and subuarines. The advances inelectronic and. inforuation processing have facilitated this inproved ASi,icapability, only in pert conpensatert by subnarine quietening p"ogrurr"".similarly, the appl-ication of modern science to magnetometers has al"lowed thealetection of submarines at ranges app?os.ching 1km. All of this, houever, is moreusefuf in tactical anti-sutnarine warfare than in hunting and ileitroying on shortnotice a Iarge, strategic SLBM fJ-eet. 136. Thus far, no effective cletecti.on technique appears to have been found. whichrouLd inperil- the SLBM freet. rf such a technique were d.iscovered., in nost casesneasures could be taken to cor.mter it. For instance, arl acoustic detectiontechni-que co'Iri be countered by the deploynent of large numbers of noise sou?cesin the ocean, either to raise the noise fevel or to sinutate the lresence ofsubnarines. rn tines of war, noise eehoes fron nucl-ear explosions in the oceanbasin could s"1so be userl to eask the presence of strategic subnarines for ah6ri ^n ^a ,t ^-.- ler +vs vr uaJD,
analysis: The text appears to be discussing the capabilities and limitations of detecting and countering the presence of submarines, specifically strategic ballistic missile submarines. The text mentions various technologies and techniques used for detection and counter-detection, such as acoustic detection, magnetometers, and noise sources. The discussion is focused on the military aspect of submarine detection and the potential consequences of discovering an effective detection technique. Given the focus on military technology and strategy, it is likely that the text falls under the category of Science and Technology.