l-28' such systens are usefur only if the varning and assessment which they givecan be acted upon to engage active or passive dJfences, to nove veapons and otherobJects of attack from vulnerable postures to fess vr.Llnerable ones, to launch onwarning those weapons which rnight otherwise be destroyed, and to determine theDetectionAl35 /392 Engr f sn Annex Page 50 orlgin of and. responsibility for an attack' It is of particular interest to note hov litt1e tine in reality is avail-able for atl of this" t29. Land-based. systems deployed in the target area have little to offer against an attack by ICBM. r'orwara-dlptoyed systems ' such as the ba'llistic nissile ;ti;:;;;ilc-systen *BI'E\{S", -"ult pto.'iau 15 ninutes I warning ' as can the hiflh- p""il".r."" !"tiy-*u'trring raitt" ii. ttre soviet union' rn generat ' the role of-a.l""tiorr, iaentlficatioi and traeking of incoming nissiles is divided betveen satellj.tes, which can detect launchin! of ballistic nissiles nainly through infrared. sensors, and various airborne or land-based' radar systems which are ernployed. to track their traiectory" 130. Sinilarly, the nPAVE PAWSr! coasta'f rad'ars in the United States can give at least five ninutes' varning before impact of SLBM nissiles launched from the Atlantic. The so-cal]'ed oin ( over ftre ttorizon) ratlar ' which util-izes the reflection of etectronalo"iJ"'*"lr"" against ionospheric layers, could. possibly detect both bal-listic nlssil.es and low-t:-ying aircraft or cruise rnissiles at very iong-"urrg., although tiir, poo. accuracy' 'Diiferent types of 0TIl rad'ar systens are now bel-ieved to be in op"tltion. Currently used ground-based air-d'efence rad'ars can assess the threat fion aircraft penetrating the airspace, arrd serve to sJert a'ti-aircraft systems. Greater tutting is available, however, from airborn or space-based sYstems. f31. It is velt knovn that there exist satel]ite systems in high earth orbit with the primary purpose of detecting and assessing mass ICBM and SLBM raids" These satellites contain a scanning infrared d'etector and must construct and' report
**Analysis**
The text appears to be discussing the capabilities of various defense systems, including satellite and radar systems, to detect and track incoming missiles and other threats. The text also mentions the limitations of these systems and the time available for response to an attack. This suggests that the text is focused on the military or defense sector, which is typically categorized under Science and Technology.

**Category**
Science and Technology