Letters Patent of the United States is: 1. A@ radar object location system comprising means 30 @or transmitting pulses. of radio frequency waves toward objects in space, antenna means compn'sing a plurality of directive reception patterns for separately receiving echoes returned from objects irradiated by said trapsmitted 1 pulses, a cathode ray tube indicator, means for producing 35 a polar sweep on the screen of said cathode ray tube indicator timed with said ptilse transmissions, means responsive to said received echoes for intensifying said sweep, means for deriving a signal from said separately received echoes having an amplitude indicative of the 40 angular position of the located object relative to the directivit y of said antenna reception patterns, and means independ ent of said sweep producing means for directing said polar sweep to an angle different from its radial direction in accordance with said derived signal. 45 2. A monopulse reidar object location system comprisiii-. means for transmittin.- pulses of radio frequency wtves toward an object in space and for receiving a plurality of corresponding echoes returned from, said ol@iect wherein said echoes contain modulation cornponents indicative of 50 the objects angular location, a cathode ray tube indicator comprisi ng a screen, means for producing a sweep iri a given direction on the screen of said cathode ray tube timed with said pulse transmissions, means for deriving a si.-nal from said received echoes indicative of said 5,5 angular location of said object, and means independent of said sweep producing means for modifyin-, the radial dire(,- tion of said sweep in accordance with said derived sigiial. 3. A radar object location system comprising means for transmitting pulses of radio frequency waves towai,d 60 objects in space, means for recpiving echoes returiied from objects irradiated by said transmitted pulses, a cathode ray tube i-iidicator coniprisidg a screen, means for producii g a radial sweep on the screen of said catliode ray tube tin-icd with said pulse transn-iissions, means for 65 deriving a signal from said received echoes corresponding to the ongular positioii of the object, a magnetic deflection element associated with said cathod-- ray ttibe indicator for direciing said radial sweep at an angle to its radial direction, and means for applying s@-id derived 70 signal to said magnetic.defl--ction element. 4. A radar object location system comprising means for transmittin.- pulses of radio frequency waves toward an object in space, antenna means comprising two spaced ,ipart directive reception patterns for s-.parately receiving 75 6 echoes rel,urned from said object irradiated by said transmitted pulses, a cathode ray tube indicator, means for producing a radial sweep on the screen of said ca de ray tube indicator ti-med with each pulse transmissioii, means res-vonsive to said received echoes for intensifying said sweep, mearis re sponsive to the relative phase of said received echoes for deriviqg -. sigii4l having an amplitude co.-responding to the angular position of said object relative to the directive centers of said antenna reception patterns, means for producin.- a - ma.-notic 'ield having an intensity corresponding I io the amplitude of said gignal, and means for directing s4id sweep at an angle to its radial direciion in accordance with said fleld. 5. A radar object location system comprising means fortransmittilig pulses of radio frequency waves toward objects in space, antehna means comprising a plurality of directive recepti n patterns -for separately receiving echoes 0 returri-ed from objects irradiated bv said transmitted pulses, a cathode ray tube indicator comprisin'g a scree I n, means for produciiig a polar sweep on the screen of said cathode ray tube timed with each pulse transmission, means for 6ombining said separately received I echbes, means for intensifying sa id sweep in accordance with sai,d combined echoes, mearis for deriving a signal from said separately received echoes having an amplitude corresponding to the angular position of the obje-ct relative to the antenna d-.rectivity patterns, a iriagneticdeflect.' on element E@ssociated with said cathode ray tube indicator for modifying said polar sweep at right angles to its weep direction, and means for applying said derived si@nal to said magnetic deflection element. -@. A radar object location system comprising means fortransmitting pulses of radio frequency waves in a narrow beam toward objects in space, antenna means comprising a plurality of spaced apart reception patterns for separately receiving echoes ieturned from obejcts irradiated by said transmitted pulses, means for angularly rotating the directivity of said patterns, a cathode ray tube indicator comprising a screen, means for producing a polar swe.-p on the screen of said cathode ray tube timed with each pulse transmission, means for angularly rotating said sweep in synchronism with the rotation of said reception patterns, means for combining said separately received echoes, means for intensifying said sweep in accordance with said combined echoes, means for doriving a signal froin said separately received echoes having an amplitude corresponding to the angular position of the object relative to said anteniia reception patterns, a magnetic deflection element associated with said cathode rziy tube indicator for modifying said polar sweep at an angle to its sweep directibn, and means for applying said derived signal to said magnetic deiqection element. 7. Indicating apparatus for signal display comprising a cathode ray tube indicator, said indicator comprising a screen and means for -producing and projecting an electron bearn toward said screen, a first beani deflecion element for sweeping said beam across said screen to produce a polar trace centered about a given point, @ means for deflecting sai . d swept beam at an angle to its p6lar sweep said element comprising a separate beam deflection element, comprising a coil associated with said indicator for producing a magnetic field in the path of said swept beam which is aligned with said point, signal responsive means for modifying the brightness of said sweep in AC'cordance with an applied signal and signal responsive means for varying the intensity of said field in accordance with an applied signal. 8. Indicating apparatus comprising a cathode ray tulbe, said tube comprising a screen and means for producing and projecting an electron beam toward said screen, means for simultaneously progressively translating said beam over said screen to produce a nornial trace and means for positionally modifying the rate of progression of said trace in accordance with an appli@-d sign@al, said last nanied means comprising mean s separate from said translating

7 means for producing a magnetic field in the path of said swept beam. 9. Indicating apparatus comprising a cz,,thode ray tube indicator, said indicator comprising a sci.cen, means for producing and projecting an electron beam iowards said screen, means for recurrently sweeping said beam over an area of said screen to produce polar trace thereon centered about, a giveii point, means feir modifying said trace by deflecting said swcpt beam a right angles to itg polar sweep comprising means for prodticing a magnetic field in the path of said swept beam which is aligned with said point and means for varying the amplitude of said field in accordance with an applied signal. 10. Indicating apparatus for signal displa@, coinprisin.- cathode ray tube indicator, said indicator comprising t.. screen, means for prodiiciiibg @arid projec in,- an elecc @eans for swee@in said tron@beam towaids said s reen .m 9 beam a'dross said screen t6 piodu6e a p6lar tiac@e@ over an area there on centered about a giv6-n po-int aiid sighal re-aid trac b@ d sponsive means f6r m6difyirig s e - eflectin.6@ said swept beam ai' an angle to iis'p6lar sweep comprising means for producifig- a ffia-giietic field in the -@ath of said swept beam which is oriented ,kith iesoect to s@id p6int. 1 1. iridiciting appai@tus for signal display comp'rising a cathode'ra@ tube indicafor, s6id indic@tor compri@ing 6 screen and iiieans for producing and projecting an ele tron beam to,@,ards said screen, ilieans for sweeping said beam acros@ said s6reen t6 produce a two c6ordinate trace thereon cente,ed on a given point, and meaiis for modifyi,g 'aid trace by deflecting said swept'bearh at an atigle 1 to the d rection of said trace comprising m6ans for producing two orthogonally-6rient@d magnetic fields in the path of said swept b6am _ , field@ being dimensioned to produce a result'ant magiiitic field alioed with said given point, and signal res@onsive means for varying the intensity of said fields'to control the' degreb of modificati'on of said trace. S,OP,0,541 12. Indicating apparatus for si--nal display comprising 11 cathbde ray tube indicator, said indicator@ comp . rising a . screen and means for producin and projecting dn elee tron beam to'w@ards said screen, means foi s,@veepin.- said beam ac@o ; ss said screeri o produce a trace th6ie6n, and signal responsive means for modif@ing said trace comprising means for prodlicing a first magnetic field in the path of said swept beam which is aligned in a given directi6n' and signal responsive mea@s for producing a sccond mag10 netic fielld in, the path of said @@@ept beam which is at an angle to said given direction. 113. Indicatiiig apparatus for signal display cbmprising a c a t h o d e r a y t u b - @ i n d i c a t o r , s a i d i n d i c @ t t o r c o m p r i @ s - i @ n g a screen, means for producing aiid projecting ati electron 15 beam towards said screen, riieans'for tecurrently s,@Veeping said beam across said ser6en t6 l@roduce'polai- traces ed @@out a -iv '.it, me@Lns' for there6n centei en poli an(-Yularly displ-.@cing s'aid tiac@s'@boiit said @oiiit, m . 6ans for producing a magneti,- fi6la -fi t@e pat@ of @s6 I id swel@t beani n. 20 which is aligne(I with sai,d point, and m6ttris for m6dif@i ri said traces compriising's.ignal r6@ponsive means fof alteiing the intensity of @said field as s@id.tiaces a're'a'n@_@ulari@ displaced. 25 Refireii@es Cited in the@ file@@ of thi@s pateiit UNITED ST-ATES PATENTS, 2,456,666 Agate- et al. D@e. 21, 1949 2,557 ' 869 G106ss ---------------- June 19, 1951 30 2,589,249 Hardy ---- -- -------- Mar. 18, 1952 2,608,683 Blewett ---- Aug. 26 1952 ----------- 2,660,721 Page ----------------- @-- N6V. 24, 1953 2,745,097 Bartelink ----- ------ --- May' 8, 1956 2,948,897 White ----------------- Aug. 91 1960 35

3 2 0 2 0 9 5 4 1 United States Patent Office P a t e n t e d F e b . 6 , 1 9 6 2 3,020,541 ELE, CTRICAL SIGNAL INDICATOR Fr.ink R. Dielzey, Jr., Alexandria, Va., assianor to General Electric Compaiiy, a corporation of New York Ffled Oct. 27, 1953, Ser. No. 388,528 5 13 Clahns. (Cl. 343-11) This invention relates to electrical signal . indicatin 9 systems and p-articularly to the type employing a cathode ray tube. 10 In systems involving the flow, storage or display 'Ofelectrical signal information, the. need often atises for increasing the information handling cap,acity of the system. This ne@-d is generajly associated ivith the - re@quirement that the further -inform-ation be accommodated, or 1,5 that the existin.-@ information be, enhanced in a simple @and efficient manner. For example in an obi(@ct - detection appiratus of@-the radar type, the location of the detected object is often-times displayed on the screen of the cathodC Tay tube indicator in terms of a maximum of two or 20 three positional coordinates. : In the past, iany additional, related information generally has been accommodated by -resort t6 @elativelv comt)licated and expensive - circuitry associated with the iiidicator. It . is therefore an object of my invention to increase, 2,5 m an improved manner, the amount of informati6n that may be accommodated by a cathode ray tube indicating 1 system. AnotheT object of my invention is to extend the use@lulness of a cathode raytube indicator by the use of - auxih,ary 30 cathode ray deflection elements. Another object of my invention is.@to fmprove the quaiity of an,@ular inforniation displayed on @a cehode ray tube indicator associated with a radar object detection sysiem. Another object of my, invention is to, provide an im- 35 proved arrangement.for displaying information on thic ser6en of a cathode ray tube. , Another object of my invention is to provide an improved arr@angement for indicating position iilformation of radar detected,,objects. 40 A still further object:of my invention is to enhance the @i @lay of angular inf-ormation available froni a monopu,lse radar object detection system, on the srreen of a cathode ray tube indicator. nt of my invention, In accordance with one embodiine 45 applicable to radar object detection systems of sa . y the monoptilse, or mtilti-beam type, the echoes received from a detected object are first processed in the radar - receiver. and then applied to a cathode ray tube indicator in a' manner to provide enhanced angular information of the 50 detected object location. Briefly the inve ntion.involves processing the phase or amplitude modulatioii @appea-rin. in the received echoes, which contain the angular info@i-ina_ tion associated with the detected o@bjects location, into a suitable amplitude mod alated signal. The resultant 55 amplitude modulated signal is applied to an ialixiliary, magiieiic electron beam deflection element associated Nvith a catliode ray ttibe, indicator in a manner to permit additional or enhanced control of th-- siveeping -of a cathode ray trace on the screen of the indicator. 60 The features of the present ini@ention which are believed to be novel are set forth with particularity in the appended claims. The present invention itself both as to its organization and manner of operation together with further objects and advantages thereof may best be un- 65 derstood by reference to the following, description taken in connection with the accompanying drawings in whicli: FIG. I is a schematic representation of the improve_- ment in angulat resolution obtainable by tise of the invention; 70 FIG. 2 is a block dia.-ram of a radar object detection and position indioation system involving the invention; 2 FIG. 3 is a group of wave forms useful in explaining the operation of the arrangement of FIG. 2; and FIG. 4 is a schematic representation of a further embodiment of the invention. In the following description of a radar position indicat ing system embodying the invention, certain wave forms, or sweep configurations are assigned at various portions of the system in order to facilitate an understanding of its operation. It, is to be understood, @owever, that such assignnients are ewployed purely by way of exainple and are not to be construed in any way as limiting the scope of the invention. Referring to FIG. 11 there is shown a plan@ position indication type of,display, commonly employed in radar object detection systems, symbolizing the transmission of pulse of el6ct-rom-agnetic waves ftom the radar station P in a n-arrow beam which is rotated about P to irradiate remote objects. This display indicates that an object 0 has been detected at a, range from the radar istation P cOrresPOiiding to the radial diqtance OP, and that ihe object has a bearin- wi@th respect to the station P correspoiidi@ig to the direction of a radial line dr@wn from P to 0 ' Since a radar b,-afii projected from P to 0 has a finite width, echoes would be received from 0 for a plu tality of successive pulse traiasmissions as has been reprqsented by the plurality of radial lines passing through 0. It should be noted that the directional fedtures of the radar beam results in an aml>litude modulation of the rec-@ived echoes wwch account for the elongated, or are 'shape of the composite echo returns 0. It ca@ be seen that this elongation of the composite ech<)es is undesirable from the standpoint of,resolving the exact angul@ar position of the detected object. To improve the @angular displa@ of detected objects on the scre6n of the catliode ray tube, the plurality of echoes received in the same be-,im width are processed and applied to the cathod@ ray tube indicator in a manner to cause each successive echo from a deterted object to be displaced towards a sin.-le spot positibn O' in accordance with the instantaenous angul-,tr displacement of @the object position from the center of the radar beam. s displacement has been illustrated in an exaggerated manner in FIGI I by showing the successive radial sweeps corresponding to suce6ssive echo returns, being deflected in towards the exact object position O'. The result is -a much . improved angular position indication of th6 detected @object. The manner in which the improvement in angular indication is obtained is illustrated in the embodimeiit, of F@TG. 2 relatiiig to a monbpulse radar object detection and location arran.-ement. Brielly a monopulse radar system employs a plurality of different antenna reception pattern.s of the phase or amplitude coniparison type, whicli yield echo signals that vary in accordance Nvith a departure of the center of the reception pattern from the "on target" angular position. In FIG. 2, there is shown a source I of ke@ling pulses of predetermined rate. j-hese pulses are applied fo ',he transmitt er 2 and catise it to supply high-powered pulses of radio frequency waves at said rate to the spaced @apart antennas 3 and 4 for irradiating remote objects in space. Echoes corresponding to the transmitted pulses reflected from these remote object@ are received by antennas 3 and 4 and processed in a manner to be disclos(--d shortly, to yield range and angular information of the objects' location. Antennas 3 and 4 have spaced apart directivity patterns adapted to peri-nit angular detection of remo+,e objects, irrad@.ated by the transmitted radar pulse, by means of phase compar-is6n of the echoes received froni the objects. 'ne narrow radar beams defined by antennas 3 an-d 4 simultaneously are caused to angularly scan a 360' or any predetermiried are by rneans of motor 5 which drives the antennas about the

3,o2o,541 4 Radar System Engineeriiig,: page 667, Louis 1,T.,RidQn otir, N . ' , V . 1947, @MeGra Nv-Hill BoOl@,@. Company, Inc. i'@ew York@ . f r o d ' e c t o t 2 9 i s O f t i l e The@ outpiit signal available nl eL o w n . l @ t s h 6 d b e n c @ ', e d th at th e form sh in FIG. 3h ul detected object?s angular position is@ de-f4,ied by the poiiit @where the amplitud e of sigiial shown in F!G. 3b pass--F, @throug h: zero Ett .30, ar@d thdt the ampl.itud e vai-iel; linearly in the@ positivegcling and negative -going directibn a d of th@ f-rom this @point. Tjie reve@- se slopes,at either en @is 10 characte ristic @may be disr6gar ded@@ Us,e is mad,-- of th-@ desir-- bla linear char@ct eiistic passing tlirougli 30 bY 9Pplying @ the@ phase@ detect6r outpi@t @throtig h a pushp,-Ill video amplifier stage 311 @to the auxil[iar y magneti c deflect . 0 f the el ment 32. in ,i,particular embbdiment@ o IIIi n e 15 ventioift, theele'nient 32 c6inprise d several turns of w,'-,i-e : @vr;Lpped @ around the@ neci@ of the @athode ray iube in a nia-@iner to@ @provid'ea iha@netic field withih the c:@,.thode :ray tube whic@h is dki@illy dir6cted to, the ci-.nti'al poliit (cor@esp6i idiiig to p(@int P 6f FIG. 1) of the radial traces 20 produ ced @ on the @cr6en' @ 12 Th& effect of applyiiig t'ne pi:)sitiv6, -goind aiid neg@tiN ia-g6iTig amplitud. - sigii,)Is@ to t@lie elenient 32, is, t6 cause. the amtititud e 6f the mignetic ve6t6r H, i!6s@r ibink the meign etic field, to, VarY cormi ssionib yante nnas3 and4 @ Upoiit hestib seque@jtlre cep@@i @ espic) Tidin.- I@ @nd io I enang e sign as i@dic @ted by the solid tion at ajitehn6s@ 3 a@md 4@ <)f an echo siirial, coiresp6n I din2 25 and dotted arrow'' hi@a(l. The, am@littide modulptio@ of o f 3 vertical axis 6. Thiis th6 radar systeiai is able to irretdiate @nd 'thereb3, detect 6bjects lbeated about 'it. in order to dis .play tl-ie detected obje--ts, e. cathode ray tube indicator 7@i pr6vided. Indicator 7 comprises a cathode '91 constituting a source of an electron@ beam, and a control@electrode 8 f6r intensity modulatirig tlle elc,-,tron beara. @ A pair of tnagnetic @ de@'lection elenients liD and' 11 ,ire provided for@ deflectiiig or @sweepin.- the electron beam, s in a @desired manner across the sc@een @ 12, and @ thereby@ cause @ a s' vi ible trace, simil@r to that shovvii in @FIG. @ 1, tG be produced tllereon@ @ @-fhe detaits of the phosphorescent !screen, the forming ahd@ focusing o@' the@ electron beam, etc. are v@eli k-@no,2vii'-.n the art and; consequently @are omitted. to obtain the pla:n position iy@ e of indication, previouslv @described in ;connection with FIG 1, @a sweep ge-iera.ti)r 13:, is erriploye@d to genera@te@ @ectirrent ele(- troh beaii-, deftectibn,i sigiials of@ th@ @pijsli-ptill typi@ iii @res@6@Se@ to @ach k6yin g@litilse"delivered b@ key6-r l@ 'nit@se; derection signals, upoh 4IDiilication t6 the:defle@ti6ti@el-e --- eiit 10 and c@,ius6 the@ cleciron bearn to rqdiallv outwird @toni a cehtral point on@ @the screen of the cathode ra@ t ube ilidtcdtdr @12- in syn@hronism@ with @d@ich pul.@e transto areflection of the high powered tr itted pulse fioni t@e ihagn6t!c fi6ld ansm H al6ng th@ axial di!-6etion the cathode ray tube indidat6r 7 causes the electro@ beaffi a detected object. I I A 'giial@ is i-@enerated @ and applied over lead 14 to elec- which emanates; frbni the c@thode 8 A-.id which is deflec-@ Si @trode@8 in a manner@to be des6iibed @hortl@. 'I'his sigilal t6d radiall@ fiom;the central point 6n the sdi-een 12 in cau@es the radial tr@ice to b(, ifitensified at a point. distant . 30 accordance wi[ih' t@e @we@-p'@i-nal@ a@plied to deflection frorti its central@ poirit, corrdsponding to the, range of the elements 10 and i@l, t6 be@ fu'rther' de-flected @ at an I angle ec dicate@ the an Dwn @t O@ in FIG. I As @det ted object. , In order t6 in -gillar t)6sition t6 the radial deflection as sh, of the deiected object the d6'@lection @ elements are caused the radial @traces of FIG.' I appr6ach the 'on tar@et @osi@ I tion O', the @ iv sgnals @ d; @ 'sh, @and @t6 be phy icall[y rot@Lted in the housing 15, abo krge positive-going i imini ut thc@ neck of the cathodc@. ray tube ihclicator, 7@ in synchronism W'ih 35 when the radial,trac@s start i6aving, the-@on target @position@ i 0, the aiite@na position by @n@leahs of the me the @ negative@going sign-,Lis in@rc@@se in ampli@Lude in a chatiical drivil@g connections@ 16 @and 17 to. motor@5@ @rhis@ rotation causes rnanner @to caus@ succe@;sive echo6s, received dtjiing the the angular posit , ion of the radial@tr4@e io follov; th6 dir6c- s@@n6 @garri width@ t6 be piled' upon one another at the, ti n in @vhich the @ntennas 3 and @4 are it o@. 'ni@s instead'6f bbt'ainiug@an'elongated or arc 0 pointing@ and there- poll fbre, to ind ate@ @the@ angular direction@ of any object from 40 type of indicatioii repres,entii,ia, ihe angular p6sition @oi the which echoes 'are being received. deteci ed obj@ects @iocation, a sharply'defitied spot is: obThe plan po . sition type of indication described so far in tained coinciding substantially with the true, sliarply deconnection with FIG. 1, because of th finite widths of fined an-ular locatioli. e the reception pattems of antennas 3 and 4 would normally While the invention bas been d@scrib.ed in terms of a cause an elongated or arc type of echo indication 0, FIG@ 45 centered plan position type of indicati6n, it is obvious 1 to be obtained. In order to derive the m6re desirable that the invention can be readily adapted for other types spot type of indication O, the following arrangement is of displays. For example in FIG. 4 the inventiori is apemployed. Returning to FIG. 2, the echo signals replied to an off -center type of plan position indicati6n asceived by antennas 3 and 4 are applied through separate sociated with sector scan antenna o@eration. In this arTR boxes 18 and 19 and to respective mixer circuits 20 50 rangement the normal deflection elements, corresp6nding and 21. The TR boxes operate in well known manner to 10 and 11 of FIG. 2, cause the radial sweep AB, to block the application of the high poivered radar pulses emanating from the point A, to take up successive anfr6m transmitter 2 to the mixer circuits 20 and 21 during gular positions in the Die-section outlined by BAC. This the transmitting periods, while permitting the much type of off-center display is popiilar where it is desired weal-er echo signals to be passed with high efficiency. The 55 to magnify a @given sector of scan by making use of the separate echo signals passed by the TR boxes are conentire face of. a cathode ray tube screen. Since tl-ie radial verted to an intermediate frequency by mixing with local swecps in this arrangement are caused to emanate from osciuations available from oscillator 22 in the respective an off set poilit A, rather ttian from the center of the circuits 20 and 21. After amplification to a suitable level screen of the cathode ray tube, it is necessary that the in respective amplifiers 23 and 24, the echo signals are 60 magnetic field, defined by the auxiliary deflection eleadded to.-ether in circiiit 25, amplitude detected by cirment, be oriented in the direction of the off-center point cuit 26 and applied over lead 14 to electrode 8 for inA as indicated by the dotted line extension 31. This tensity modulating the radial cathode ray trace previously can be readily acconiplished in 6ne way by physically descr-ibed at the proper range of the detected object. The@ orienting the lbops comprising the auxiliary deflection eleshape of the echo signal-availnble at electrode 8 is similar 65 ment so that the desired magnetic field directivity is obto that shown@in FIG ' 3a. tained. In the - arrangement of FIG. 4, however, the auxThe amplified echo signals from 23 and 24, are also iliary windi.ng. portion 31, @which would normally proapplied through respective circuits'27 @and 28, where their vide a magnetic field along the axis of the cathode ray amplitudes are first limited to a predet6rmined level, to tube, is augmented by introducing a magnetic field at the phase detector 29. Phase detector 29 delivers an 70 right angles to this ixial direction by use of compensatoutput signal having an amplitude proportional to the ing windings 33 and 34. This arringement is so dimenphase difference of the related echoes received at antensioned electrically that th I e axial fiel@- and the orthogonal nas 3 and 4 and available from limiters 27 and 28. For field combine to produce the desired @ directivity of the -ftirther details of the detectc@r operation, reference may majinetic, field indicated by the orientation of the magbe made to the Radiation Laboratory Series, vol. #1, 75 netic field vector H. In otber respects the arrangement

8,020,54i of FIG. 4 is similar to that described in connection with FIG. 2. The resultant magnetic field prpduced by the auxiliary winding 32,and the comp-.nsating,.windings 33 and 34, causes the successive echo indications produced on the screen of the cathode ray tubes to be deflected to- 5 wards the exact detected object location point O' as shown in FIG. 1. VA-iile the invention has been described with respect to a particular type of display, it is obvious that other displays may be accommodated. For example, the sys- 10 tem is generally applicable to any radial type of sweep in which a further deflection at @an angle to this normal sweep is to be provided in accordance with available signals. Furthermore the invention is applicable to other forms of radar object detection systems, such as the am- 15 plitude comparison, or combined amplitude and phase pompari son monopulse type. It riaerely being necessary to derive the desired, encbanced object location information from the modulation components contained in the received echoes and to modify the normal -radial swe-P 20 descripti ve of the object's location accordingly. While specific embodiments have been shown and described it will, of course, be understood that variotis modifications may be made without departng from the principles of the invention. The appended claims are there- 25 fore intended to cover any such modi.-qcations within the true spirit and scope olf the inven'tion. What I claim as new and desire to secure by