Патент USA US2403429код для вставки
July 9, 1946. E. l. ANDERSON 2,403,429 RADIO BEACON SYSTEM Filed Nov. 2, 1942 JUUL 54w 2;roar/1 WI .5 v 3 Sheets-Sheet 2, Cad/V753 / .a// L J5 mm J9 GENE/P147018 / ‘ 4/ M ' :/_ A r PECE/l/EB “ 1L, Z1 Fgg F5714 lynx. . $2 . Zmventor Earl Z?mkmm 6&2. M (Ittorneg r Patented July 9, 1946 EN UNITED STATES _ 2.403.429 asmo BEACON srs'ram Earl-I. Anderson, Manhasset, N. Y., assignor to Radio Corporation of America, a corporation of ’ Delaware ' Application November 2, 1942, Serial No. scam 7 Claims- (Cl. 250-—11) 2 I This invention relates to a course and position Figs. 8 and 8-11 show a modi?cation oi? the determining system employing radio beacons, and system of Fig. 5, Figs. 9, 10, 11 and 12 show various types of receiving apparatus carried by a. mobile craft or vehicle whose position is to be ascertained. indications which may be produced by the sysm ' Radiogoniometric systems, in which bearings of two or more ?xed stations with respect to a 5 tem of Fig.8, . » Fig. 13 illustrates another modi?cation of the craft are used to determine its position by tri_ angulation, are subject to various well known sources of error. Under certain conditions of ‘system of Fig. 5 ; and occur at a time when it is impossible to obtain a low a course along the line AB, perpendicular to ?x by astronomical or other means and depend~ ~able radio location is most required. and biseoting the linebetween thev transmitters . . - - Figs. 14, 15, 16, 1'7 and 18 ‘show typical indi~ cations obtainedwith the system of Fig. .13. abnormal-wave polarization and high noise level 10 Referring to Fig. 1, assume that transmitters are located ‘at X and Y, and it is desired to 201- ' such systems are useless. These di?lculties often X and Y. Discrete pulses of high frequency en» It is proposed to use two or more fixed trans 15 ergy are periodically emitted simultaneously by transmitters X and Y. These pulses are trans mitt'ers sending timed impulses to, determine the mitted on different frequencies and picked up by relative time required for a' pulse from each of separate receivers at the mobile station. The the transmitters to travel between theilxed sta tions and the position to be determined. Since ‘ outputs of the two receivers-are applied. to a the velocity of propagation of radio waves is in 20 multigrid tube arranged to produce output cur~ rent only when the input pulses coincide. This variable, the time is in each case an accurate measure of the distance. Although re?ections ' ' output current is applied to a peak indicating device. ' ‘ and deviations of the wave may occur, as long as any component of the radio energy travels over As long as the mobile‘ station follows the course the direct path, it will arrive ?rst at the receiver. 25 AB the arrival of the pulses from the two stations will coincide, producing an output pulse lilsethat 3 The position may be ascertained in terms of the shown in Fig. 2. When the mobile station is oil relative time of arrival of pulses from the fixed s a ons. It is an object of this invention to provide the course AB, theoutput pulse will decrease in I ' ' amplitude, reaching zero when the di?erence in improved method of and means for determining 30 time 01’ arrival exceeds the duration time of one." position. ' ‘ . _, pulse. This is illustrated. in Fig. 3. . .. Another object is to provide a system for as ' In order’ to indicate the arrival at a destinae certaining the position of a receiver station in ticn, a third transmitter Z, may be ‘provided any where along the course AB and arranged to send terms of the times of arrival of pulses transmit ted from stations of known positions. 35 out pulses like those from x and Y, but with I A further object is to provide an improved a slight delay, so that when all ‘three pulses coin method of and means‘for indicating automatical- ' cide at the receivers, the craft is at its destina~ tion, indicated by the point P in Fig. l. I ly the position of a mobile. craft with reference ~ Referring to Fig. d, an indicator system is to a given course and destination. Other and incidental objects will become ap 40 shown, com-prisms receivers‘ X’, Y’, and Z’ an parent to those skilled in the art upon considera ranged to respond to transmitters K, Y and 2; tion of the following description, with reference respectively. Receivers X and ‘if are connected to the accompanying drawings, of which Fig. 1 .to two control grids oi’ a multigrld tube 6. The represents the course and destination of an air control grids are both normally biased to cut oil? plane, for example, with reference to ?xed ground 45 by means of a voltage from e110. source (not stations. . shown) applied between the cathode of the tube Figs. 2 and 3 illustrate pulses received from I and the grid leaks 3 and 5. the ground stations at a receiver on the airplane. The plate circuitof the tube l includes a load resistor 'l coupled through a blocking condenser tem for providing indication of the position of a 60 8- to' a peak indicator comprising ameter ii receiver with respect to three transmitters, shunted by a recti?er it. Fig. 5 is a schematic diagram of a modified A second multigrid tube l5, biased like the tube ' Fig. 4 is a, schematic circuit diagram of a sys 1 _ 1, has. one control grid connected through a Figs. 6 and 7 illustrate typical indications pro phase inverter it to the plate circuit of the tube vided by the system of Fig. 5, 1 55 I and the other connected to the receiver Z’. A indicator system, aaoaeao ' 4, 3 peak indicator including a meter l7 and recti?er l9 is'connected to the plate circuit of the tube in. ’ 66, and the vcathode is coupled vto the grid of In operation, the plate current. pulses of the tube l are‘ directly related in magnitude to the coupled to the grid of a tube 14, andthe cathode of, the tube is is coupled to the cathode of the time of overlapping ofthe pulses received by the tube M. receivers X’ and Y,'. Thus the meter II will show The tube 36 provides a, duplicate of the wave 35 (Fig. 8) in its cathode circuit, and a similar another tube 42. a maximum de?ection when the craft is on The plate of the tube 42 is _ but inverted wave _ in its plate circuit. course, and a decrease upondeparture from the course. Similarly the de?ection of the meter ll The tubes 68 and 412‘ are arranged to operate as peak will increase as the destination is approached, 10 "ampli?ers, “clipping” the highest step of ‘the stepped wave in each case. Thus the output at the cathode of the tube 40 is the wave 43 of and dropping 01! again if it is passed. Fig. 5 shows a system for producing course Fig. 8 and that at the cathode of the tube 42 is the wave 39. The outputs at the plates of these and destination .indications on the screen of a tubes are similar to, but inverted with respect to cathode ray tube. A saw-tooth generator 2!, the cathode outputs. The wave II is provided by which may be a blocking oscillator, for example, applying both of the waves 39 ad 43 to the tube ' of the type described in U. S.\Pat. 2,101,520 to as so as to provide cuto? bias. Thus the tube Tolson et al., is synchronized with alternate ‘ pulses in the output of the receiver x'. The will conduct when both voltages 39 and. ' “t attaining a maximum value when it is reached output of the generator II is applied-to the hori zontal de?ection circuit of a cathode ray tube a are oil’. . ,_ The ampli?ers as, 61 and 49 may comprise multigrid' tubes and circuits like those shown in 23, and the outputs of the three receivers X’, Fig. 4. or may be any other type'of amplifier Y’, and Z’ are applied together to the vertical arranged to be normally cut oil and made oper de?ection circuit of the cathode ray tube. Alternate pulses in the output of the receiver 25 ative by arrival of a keying impulse. Receivers X, Y’ and Z’ are connected to the inputs of ampli X’ will produce a de?ection 25 at the center of flex-s d5, 657 and lit respectively. The ampli?er the cathode ray trace 21 (Fig. 6). The pulses outputs are applied to the vertical de?ecting from receivers X’ and Z’ will produce de?ections 29 and 3| which are displaced from, the center circuit of the tube 215. as functions of time. ' When the de?ection 80 ' The operation ‘oi.’ the system is as follows: caused by the receiver Y’ coincides with the central de?ection 25, the receiver station is on course. when all th ee de?ections coincide, the destination has been reached. In this applica~ tion the shape of the pulses is not critical except, Each alternate pulse from the receiver X’ causes the cathode ray to trace one horizontabsweep. with its center coinciding in time. with thein termediate pulse from recevier X’. The coun ter lit is operated by each saw-tooth wavaso that they should be as short as possible tot‘ that each step in its output has a duration equal maximum accuracy. Fig. '7 shows a portion of to twice the pulse repetition time. The keying pulse generator 3? produces a square wave at the trace on the cathode ray tube when the re‘ each of its output circuits corresponding in time ceiver station is slightly oi! course and near the destination. There is no easy way to distinguish 40 to one level of the stepped wave 35. Thus the ampli?ers Alli, ti and [.59 are sequentially keyed to . which de?ection corresponds to the course indi operate successively, each for a period equal to cation and which to the destination indication. This information must be determined by going twice the pulse repetition time. The wave-1'" first one way and then the other, long enough to may be applied to the vertical de?ection circuit, move the de?ections a perceptible distance along 45 as shown, to cause successivé horizontal traces the trace. If all three pulses arrive at the same to appear at different levels. During successive traces the impulses from receivers 'X', Y’ and time it is impossible to tellif one, two. or three pulses are present, even if the amplitudes are Z’ are successively indicated on the screen, re di?’erent, since only one composite pulse results. sulting in an indication like that shown in Fig. Fig. 8 shows a system for displaying the re 50 10. If the voltage 85 is not used, ‘the patterns ceived pulses during separate scans of the cath~ will he like that shown in Fig. 9, or if the out ode ray beam, retaining the form of each pulse, even though they arrive coincidentally. The receiver x’ synchronizes a saw-tooth generator puts of the different channels are unequal, like Fig. 11. An indication like that shown in Fig. 12 may he obtained by reversing the polarity.‘ of H on alternate pulses, as in the system of Fig. 65 one of the ampli?er outputs, by- means oi" a 5. The oscillator output goes to the horizontal phase inverter stage 66, for example. The two de?ection circuit of the cathode ray tube 23, and lower pulses may be used to indicate course and also to a counter circuit 83, which may be of. the upper pulse used to show the destination. Fig. 13 shows a system for providing indica the type described in British Pat. 471,731, of Dec. 4, 1935, to E. L. C. White adjusted for 3 to 630 tions like those shown in Figs.‘ 14, 15; 16,.17 and 1 frequency division to produce the stepped wave 18, which can be more readily interpreted than 35. The counter output is applied to one side , those given by the above described systems. Fig. of the vertical de?ection circuit of the cathode ray tube 23 and to a keying pulse generator 3?. The keying pulse generator provides three square wave outputs, 38, ll and 43, each corresponding ‘in time with one ,of the steps of the wave 35. These outputs are. applied to key the amplifiers‘ 45., 41 and 48 respectively. The circuit of the keying pulse generator 31 is shown in Fig. 8A. The stepped wave output of the counter 33 is applied ‘to the grid circuit of a tube 34. The tube 34 is provided with load resistors as and 38 in its plate and cathode circuits respectively. ‘ The plate circuit is coupled to the grid of a tube, 14. shows the indication when the craft'is on course. Figs. 15 and 16 are o?-course indications. to the right and to the left respectively. Fig. 17 indicates the mobile station is on course and nearits destination. Fig. 18 is the indication-of arrival at the destination. Thus the image‘on the cathode ray screen simulates a map showing the ‘positions of the craft and its destination. and the course to he followed. ' j The indicator system (Fig. 13) ‘comprises a saw tooth wave generator a! synchronized on alternate - pulses in the output of the receiver X’, as in the systems of Figs. 5 and 8. A pair of keying: i I 5 2,408,489 ampli?ers It and IS, which may be multigrid tubes biased like the tubes i and ii of Fig. 4, are each connected to produce output only when sig nals are applied to both control grids. The output of the saw-tooth generator 2| is applied to 'corre— sponding control circuits of the ampli?ers 53 and II and to a two to one' counter circuit 33. The output of the counter 33 is applied directly to the 6. I claim as my invention: ' 4 ' 1. A system for indicating a position in response “ to arrival at said position of pulses transmitted in predetermined time relationship from a plu rality of spaced transmitters, comprising receiver means, a cathode ray tube, means for initiating a sweep of- the beam 01' said cathode ray tube in response to the arrival of each alternate pulse other of the control inputs of the ampli?er 53 and fromone oi’ the transmitters, and means for de through a phase inverter ii to the corresponding‘ to ?ecting said beam transversely of said. sweep in circuit of the ampli?er $5. . The output circuits: of response to the arrival of pulses from each of the the ampli?ers BI and 55 are connectedto the vertical and horizontal de?ection circuits respec tively of a cathode ray tube 23. " The output of the counter II is also connected through a phase inverter 50 to the vertical de?ection-circuit of the tube 23, and the output of the phase inverter ii other transmitters. is similarly connected through a phase inverter 51 ' 2. A system for indicating position in response to the relative timings of‘ a plurality of trains oi’periodic impulses comprising a radio receiver arranged to respond to one of said trains, a saw tooth wave generator controlled by the output of said receiver to operate at a frequency‘ one half to the horizontal de?ection circuit. The receivers of the impulse repetition frequency of said train, Y’ and z' are connected throughswitches 6i and 20 other radio receivers arranged to respond respec II to the vertical and hprizontal de?ection circuits - .tively to others of said trains, and a cathode ray respectively 01’ the tube '23. Switches II and 63 tube provided'with a horizontal de?ection cir- ‘ may also be operated to connect the receiver X’ cult connected to said saw-tooth wave generator instead of receivers Y’ and Z’ to the de?ection and a vertical de?ection circuit connected to said circuits. other receivers. ‘ ~ ; , ' . ' ' The ampli?ers .53 and 85 are keyed alternately by the output currents 85 and 81 of the counter 33 and phase inverterv 5i, respectively to produce ~ to the relative timings of a plurality of impulse alternate horizontal and vertical sweeps of the respond to one of said trains, a‘ saw-tooth wave 3. A system for indicating position in response trains comprising a radio receiver arranged'to cathode-ray beam of the tube 23. The outputs so generator controlled by the output of said re It and ‘H oi’ the ampli?ers 53 and 55, if applied alone to the respective de?ection circuits of the ceiver and arranged to synchronize with alter nate impulses of said-train, a frequency divider tube 23, would produce alternate vertical and ' ' connected to said saw-tooth wave generator and horizontal sweeps from the unde?ected spot posi arranged to produce in response thereto a stepped tion, at the approximate center of the‘ screen. 35 wave; each step thereof corresponding in dura The traces would intersect at their ends at this tion to one cycle of operation ofsaid saw-tooth point. The phase inverters-S1 and 59 add- square wave generator, square wave generators arranged wave components derived from the counter out to operate selectively in response to the occurrence put to the outputs II and 88 of the keying amph of respective levels of said stepped wave, other ' ?ers, providing resultant voltages ‘I3 and 15 re 40 radio receivers arrangcd'to respondirespectively -' spectively. This is done to make the vertical and . horizontal cathode ray traces cross at their centers to others of said impulse trains, ampli?ers con nected to the outputs of the-receivers and each by shifting the axis of the sawtooth waves 68 and ' arranged to be controlled by one of said square ‘H from zero voltage to one-half the peak voltage. wave generators, vands. cathode ray‘ tube, with 45 Alternate pulses, in the output 01’ the receiver a ‘?rst de?ection circuit connected to said saw X'_control the initiation of each sweep, which tooth wave generator and a second de?ection cir requires a time equal twice the pulse repeti cuit connected to'sald frequency divider and to tion period. An impulsereceived on receiver Y’ allof said ampli?ers. _ _ during the horizontal sweep period produces a 4. A system for determining position in re vertical de?ectionf'if this coincides with an im sponse to the relative timings of a plurality oi pulse from receiver ‘X21 the de?ection occurs at impulse trains comprising a plurality of radio the center of the horizontal sweep. A pulse from. - receivers, each arranged to respond to one of receiver Z’ during. the vertical sweep‘ produces a said trains, a cathode ray tube, means for de horizontal de?ection, above or below the center ?ecting the beam of said cathode ray tube in according to whether it‘ is later or earlier than alternate sweeps at right angles to each other,, the pulse from x'. vWhen all three pulses coin-‘ said means being arranged to respond to the out-. '. side in arrival, the ‘de?ections both occur at the put of one of said receivers so that each of said intersection of the sweeps. . sweeps has a duration of twice the pulse repe The switches ti and $3 are provided so that tition, period of said output,‘ and means for de-> the output of the receiver x' may be applied to forming each of said'sweeps in response to im either of the de?ection‘ circuits to enable observa- ' pulses in the output of a corresponding one of tion of the amountloi square wave component the others of said receivers.v ' ' , added to each of the de?ection saw-tooth voltages, 5. A system for indicating a position in re for the purpose of adjustment. ~ ' . sponse to the relative timings of a plurality of ‘ Thus the inventiomhas been described as a 'trains of periodic impulses comprising a radio re-v course and destination indication system for ceiver arranged to respond to one of said trains, mobile craft. Trains of suitably timed impulses ‘a saw-tooth wave generator connected to said ‘ are transmitted at equal repetitionperiods from receiver and arranged to initiate a cycle in re a plurality of listed stations and received at the sponse to the arrival of each alternate impulse of mobile station. Coincidence of two of the pulse 10 said train at receiver. a_ cathode ray- tube with trains at the receiver station occurs when the one de?ection circuit connected to said saw-tooth craft is on course, and coincidence of all three v . occurs at the destination. Several arrangements ' wave generator- whereby the beam of said cath ode ray tube produces ‘a linear'trace on the screen for providing visual indications in response to the received pulses are illustrated. - ' thereof, other radio receivers arranged to respond respectively to others of said trains, and con '8 nections from the output circuits of all of said other receivers and another de?ection circuit of beam transversely of said sweep in response to said cathode ray tube whereby said linear trace the arrival or the pulses of each or the other or said pulse trains. is deformed at points along its length related in their positions to the [relative timing of said im cathode ray tube in response to the relative tim pulse trains. , V 6. The method of indicating on a cathode ray tube‘ the position or a station in response to ar rival at said station of a plurality of trains of timed pulses, comprising the steps of initiating a sweep of the beam of said cathode ray tube in response to the arrival of each alternate pulse of one of said pulse trains. and de?ecting said 7. The method of indicating position on a ‘ ings of a plurality‘oi trains comprising the stem‘ of de?ecting the beam or said cathode ray tube in alternate sweeps at right angles to each other in response to the successive alternate pulses of one of said trains, and deforming each of said sweeps respectively in response to the pulses of ' corresponding other trains. EARL I. ANDERSON.