AN / FPS - 17 The AN / FPS - 17 is a ground - based fixed - beam radar system that was installed at Pirinçlik Air Base in south - eastern Turkey . This system was deployed to satisfy scientific and technical intelligence collection requirements during the Cold War . The first installation ( designated AN / FPS - 17 , XW - 1 ) at Diyarbakir was originally intended to provide surveillance of the USSR ' s missile test range at Kapustin Yar south of Stalingrad - especially to detect missile launchings . The data it produced , however , exceeded surveillance requirements , permitting the derivation of missile trajectories , the identification of earth satellite launches , the calculation of a satellite ' s ephemeris ( position and orbit ) , and the synthesis of booster rocket performance . The success achieved by this fixed - beam radar led to the co - location of a tracking radar ( AN / FPS - 79 ) , beginning in mid - 1964 . Together , these radars had the capability for estimating the configuration and dimensions of satellites or missiles and observing the reentry of manned or unmanned vehicles . Genesis . Experimentation with the detection of missiles by a modified SCR - 270 radar in 1948 and 1949 at Holloman Air Force Base , New Mexico along with U . S . experience in the use of high - power components on other radars , created a basis for believing that a megawatt - rated radar could be fabricated for operation over much longer ranges than ever before . The need for intelligence on Soviet missile activity being acute , a formal requirement for such a radar was established , and Rome Air Development Center was given responsibility for engineering the system . In October 1954 General Electric , which had experience in producing high - power VHF equipment and radars , was awarded a contract for the fabrication , installation , and testing of what was to be at the time the world ' s largest and most powerful operational radar . The contract stipulated that the equipment was to be in operation at Site IX near Diyarbakir within nine months : by 1 June 1955 . Construction began in February , and the scheduled operational date was missed by fifteen minutes . The original antenna installation was a large D . S . Kennedy parabolic reflector , high by wide , radiating in the frequency range 175 to 215 megahertz . Standard GE high - power television transmitters , modified for pulse operation , were used initially . Surveillance was carried out by six horizontal beams over the Kapustin Yar area . In 1958 a second antenna , high by long , and new 1 . 2 - megawatt transmitters were installed as part of a modification kit which provided three additional horizontal beams , a seven - beam vertical fan , and greater range capability . The elaborated system includes automatic alarm circuitry , range - finding circuitry , and data - processing equipment ; it is equipped to make 35 mm photographic recordings of all signals received . A preliminary reduction of data was accomplished on - site , but the final processing was done in the Foreign Technology Division at Wright Patterson Air Force Base . From 15 June 1955 , when the first Soviet missile was detected , to 1 March 1964 , 508 incidents ( sightings ) were reported , 147 of them during the last two years of the period . Operation . The system has eight separate radar sets or channels , each with its own exciter , transmitter , duplexer , receiver , and data display unit . These eight channels feed electromagnetic energy into sixteen fixed beams formed by the two antennas , each channel , or transmitter - receiver combination , being time - shared between two beams . Pneumatically driven switches operate on a three - second cycle to power each beam alternately for 1 . 5 seconds . There are antenna feeds for two additional beams which could be made to function with some patchwork in the wiring . The antenna feeds are positioned to produce in space the beam pattern depicted in the figure . Beams 1 and 18 are those not ordinarily energized . Beams 1 through 7 use the older of the two antennas ; 8 through 18 are formed by the newer , " cinerama " antenna , whose width gives them their narrow horizontal dimension . Beams 2 through 9 are projected in horizontal array ; 10 through 17 ( although 10 actually lies in the horizontal row ) are grouped as the vertical component . All beams of each group are powered simultaneously . Except for being controlled by a master timing signal , each of the eight channels operates independently of the others . Each transmitter is on a slightly different frequency to prevent interaction with the others . The transmitted pulse , 2000 microseconds long , is coded , or tagged , by being passed through a tapped delay line which may reverse the phase at 20 - microsecond intervals . Upon reception the returned signal is passed through the same tapped delay line and compressed 100 : 1 , to 20 microseconds in order to increase the accuracy and resolution of the range measurement , which is of course a function of the interval between transmission and return . A delay line is an artificial transmission detour that serves to retard the signal , made up with series inductances and parallel capacitances that yield a constant delay . Pick - off points at 20 - microsecond intervals permit these sub - pulses to be extracted in such sequence that they all arrive together , to achieve the compression effect . The total azimuthal coverage is from 18° to 49 . 7° . The system normally detects missiles or satellites launched from Kapustin Yar at a nominal range of ; it tracks one type of missile out as far as . The missiles and satellites are not sensed at their maximum detectable range because the coverage of the fixed beam configuration does not conform with the test range layout . The electrical characteristics of each of the channels are : To illustrate how the capability of the system is calculated , we can take typical logs which show channel 4 , for example , operating with the following parameters : Channel 4 ' s maximum range of intercept capability for a target one square meter in cross section is then determined by using these parameters in the radar range equation where : Substituting , where : converting . and Sightings made by the fixed - beam system include vertical firings ( for upper - atmosphere research vehicles or booster checkout ) , ballistic missiles fired to the nominal , , and impact areas , launches of Cosmos satellite s , orbiting satellites , and natural abnormalities such as ionospheric disturbances or aurora . Measurements and processing . Data on target missiles or satellites are recorded in each radar channel by photographing a five - inch ( 127 mm ) intensity - modulated oscilloscope with the camera shutter open on a 35 mm film moving approximately five inches per minute . The range of an individual target is represented by its location across the width of the film , the time by a dotdash code along the length . In addition to this positional information , the target ' s approximate radial velocity ( velocity in the direction of observation ) was determined by measuring the Doppler frequency shift in the radar signal when it is returned . The doppler shift is found to within 500 cycles by determining which of eighteen frequency filters covering successive bands 500 cycles per second wide will pass the return signal . This measurement of radial velocity runs from - 4 to - f - per second in increments of . All these data , together with the elevation and azimuth of the observing beam , are automatically converted to serial form , encoded in standard teleprinter code , and punched on paper tape for transmission . Data was thus received at Wright - Patterson Foreign Technology Division ( FTD ) first by teleprinter and then on film , the latter accompanied by logs giving data on the target as read by site personnel and data on equipment performance such as peak transmitted power , frequency , and receiver sensitivity . Upon arrival , the film when was edited and marked to facilitate reading on the " Oscar " ( preliminary processing ) equipment . Targets are sorted by differences in range and rate of range change , and the returns on each were numbered in time sequence . The FTD Oscar equipment consisted of a film reader which gave time and range data in analog form , a converter unit which changed them to digital form , and an IBM printing card punch which received the digital data . The Oscar equipment and human operator thus generated a deck of IBM card s for computer processing which contains the history of each target ' s position through time . The first step in the computer processing is to translate Oscar units into actual radar range , " Z " ( Greenwich mean ) time , and beam number , the latter fixing the azimuth and elevation of the return . During this first step , three separate quality - control checks are made on each IBM card to eliminate erroneous data . Those observations that succeed in passing all these tests are taken to the second step of computer processing , with fitting of a second - degree polynomial curve to the raw range / time data in accordance with least squares criteria . In this method , a mathematical function is fit to best approximate a series of observations where the sum of squares of its residuals ( deviations from the raw data ) is least . If there is systematic irregularity in the reliability of the data , the residuals are weighted accordingly . A standard deviation from this curve is established , and any raw datum point showing a deviation as large as three times the standard is discarded . Then second - degree curves are similarly fitted to the azimuth / time and elevation / time data . The three second - degree polynomials - for range / time , azimuth / time , and elevation / time - are used to generate a value for position and velocity at mean time of observation , and on the basis of these values an initial estimate of the elliptical trajectory is made . In computing the elliptical path , the earth is physically considered a rotating homogeneous sphere and geometrically considered an ellipsoid - that is , its equatorial bulge is ignored in the gravitational computation but not with respect to intersections of its surface . An ellipse not intersecting the Earth ' s surface represents a satellite orbit ; one intersecting the Earth ' s surface describes a trajectory above the point of intersection . The parameters of the ellipse are iterated with the computer , establishing a best - fit ellipse constrained by a weighted least - squares criterion . Along this ellipse the target ' s track is computed - the history through time of latitude , longitude , altitude , and such velocity and angular parameters as may be of interest . A missile ' s actual range is probably shorter than that of its computed trajectory because of its non - elliptical thrusting path and atmospheric drag after its reentry . The difference is on the order of to for short and medium range missiles , for ICBM ' s . Shemya Island , Alaska . Soviet rocket tests to Kamchatka during the late 1950s increased interest in Shemya Island , Alaska at the western Aleutians as a location for monitoring missile tests from the far northeastern Soviet Union . Old facilities were rehabilitated and new ones constructed on the island , including a large detection radar ( AN / FPS - 17 ) , which went into operation in 1960 . In 1961 , the AN / FPS - 80 tracking radar was constructed nearby . Blue Fox refers to a modification of the AN / FPS - 80 tracking radar to the AN / FPS - 80 ( M ) configuration in 1964 . These radars were closed in the 1970s when the Cobra Dane phased array radar was built to monitor missile tests . Shemya was redesignated from an Air Force station to an Air Force base in 1968 . The AN / FPS - 17 Detection Radar at the Shemya AFB became operational in May 1960 , and the AN / FPS - 80 Tracking Radar became operational on April 1 , 1962 . Blue Nine refers to the project which produced the AN / FPS - 79 Tracking Radar Set built by General Electric , used with the Air Force 466L Electromagnetic Intelligence System ( ELINT ) . Aftermath . The Diyarbakir space surveillance site operated a detection radar ( FPS - 17 ) and a tracking radar ( FPS - 79 ) throughout the 1960s and 1970s . If a new space object is sensed by the detection radar ' s fans , then the tracking radar can be oriented to achieve lockon . The orientation is governed by knowledge of the appropriate " normal " object ' s astrodynamic laws of motion , or by an assumption as to launch point . Thus , if an unknown is detected , and if it follows an unusual path , it is unlikely that it could , or would , be tracked . Furthermore , the director of the radar may make a decision that the unknown object detected is not of interest ( because of the location of the FPS - 17 fan penetration or because of the lack of prior information on a possible new launch ) . In the absence of detection fan penetration ( the fan has a rather limited coverage ) , the FPS - 79 tracking radar is tasked to follow other space objects on a schedule provided by the Space Defense Center , and again there is almost no likelihood that an anomalistic object could , or would , be tracked .