mit radiation lab series, v4, long range navigation (loran) - front matter, preface, contents

8/9/2019 MIT Radiation Lab Series, V4, Long Range Navigation (LORAN) - Front Matter, Preface, Contents

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LORAN


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-. ,.

MASSACHUSETTS INS TI T C TE OF TECHAOLOGYRADIATION LABORATORY S~RIES

Board of Editor sLouIs N. RID EPJOUR,E&tor-in-ChiefGEORGE B. COLLINS , Deputy Edi tor-in-Chiej

BRITTON CHANCE , S . A. GOUDSMIT, R. G. HERB, HUBERT Nf. JAMES, JULIAN K. KNIFVJ ,JAMES L. LAWSON, LEON B. LINFORD, CAROL G. h fCINTGO~ERY, C. NEWTON, ALBERTM. STONE, Lou Is A. TURNER, GEORGE E. VALLEY, J R., HERBERT H. WHEATON

1. RADAR SYSTEM EN GINEERING~idenou r2 . RADAR AIDS TO NAvlGAT1oNHal[3 . RADAR B!dAcoNs-Roberts4. L oRANPierce, M cKen zie, an d Woodward5. PULSE Gen era tors -la s oe an d Lebacqz6. MICROWAVE Magn etronsCOllins7 . KLYSTRONS AND MICROWAVE TR1oDEsHamil!on , Knipp, and Kuper8. PRINCIPLES OF MICROWAVE CIRculTsJ fonlgomery, Dicke, and Purcell9. MICROWAVE TRANSMISSION CIRcu lTs Ragan

10. WA VEGUIDE HANDBOOKMa~CUV&11 . TECHNIQUE OF MICROWAVE MEASUREMENTS~~ O@OmerY12 . MICROWAVE ANTENNA THEORY AND DESIGNSZIWT13 . PROPAGATION OF SHORT RADIO wAvEs -Ke7r14 . MICROWAVE Du PLExERs Sm u llin a nd Mon tgom e) y15 . CRYSTAL RECTIFIERS T orrey and Whitm er16. MICROWAVE M1xERsPoun d17 . COMPONENTS HANrmooEBlackburn18. VACUUM TURE Ampl ifie rsVa~/ ey and ~a~~man19. WAVEFORMSCha n@, Hugh es, M ac~ich ol, S ayre, and William - s20 . ELECTRONIC TIME MEASUREMENTSchanCe , Huls izer , MacNichol ,

an d William s21. ELECTRONIC lNSTRUMENTS~?tZnWOOd, Holdam, a nd Ma cRa e2 2. CATHODE RAY TURE D1sPLAYsSo/ ze r, Starr, a n d Va lley23 . MICROWAVE REcEIvERs -Van Voorhis24, THRESHOLD &GNALS-LaWS~ and Uhlenbeck25. THEORY OF SERVOMECHANISMSJ a7fCeS,N ich ols, an d Ph illips26. RADAR SCANNERS AND RADoMrcs-cad y, Karelitz, a nd Tu rn er27 . COMPUTING MECHANISMS AND LINKAGES&ObO&28 . lNDExHenney


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LORANLong Range Navigation

J. A. PIERCEREsEARCH FELLO!5, CBUFT LABORATORY

HARVARD UNVEMITY

A. A. Mc~~~~IEASSOCIATE EDITOR, ELECTRONICS

R. H. WOODMARDtlEsE.ARCH FELLO\\, (:HCkT 1,.!BOHATORI

H.ARVARD UNIVERSITY

OF F ICE OF SC I EN~lF IC RESEARCH ANTI) DEVELOP MENTx.\ r I ON.k L DEFEh -SE RESEARCH COMMITTEE

FIRST EDrr[oN

q

NEW YORK TORONTO I. ON DONl;f WRAW-HILL BOOK CO.ll PA, Vi, IN(:.

1948


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LOR.4NCOP I-R IGHT, 1943, BY THE

JIcGR_~w-HILL BOOK ~OMPASY, Ixc.

.111 rights re.serwd Ihis boo{:, 01p({rts th~mo.f. mc/~1not IN,reprodIIredin any for;rI u!iihotd prrtt)i, ssion of

the publishers.


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LORAN

EDITORIAL STAFF

L. A. TURNERJ . A. PIERCE

A. A. MCKENZIER. H. WOODWARD

CONTRIBUTING AUTHORS

D. DAVIDSON i%. J . POTkJ . H. HALFORD B. W. SITTERLYR. B. LAWRANCE G. C. TREMBLYG. H. MUSSELMAN J . A. WALDSCHMITTJ . A. PIERCE J . C. WILLIAMS

R. H. WOODWARD


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Foreword

T HE t remendous research and development effor t that went in to thedevelopment of radar and rela ted techniques dur ing World War IIresulted not on ly in hundreds of radar sets for military (and some forpossible peacet ime) use but also in a grea t body of informat ion and newtechniques in the elect ron ics and high-frequency fields. Because thisbasic mater ia l may be of grea t value t o science and engineer ing, it seemedmost impor tant to publish it as soon as secur ity permit t ed.The Radia t ion Labora tory of MIT, which opera ted under the super -

vision of t he Nat ional Defense Research Commit t ee, under took t he gr ea tt ask of pr epa rin g t hese volumes. The wor k descr ibed her ein , h owever , isthe collect ive result of work done at many laborator ies, Army, Navy,un iversity, and indust r ia l, both in this count ry and in England, Canada,a nd ot h er Domin ion s.The Radia t ion Labora tory, once it s proposals were approved and

fin an ces pr ovided by t he Office of Scien tific Resea rch a nd Developmen tjchose Louis N. Ridenour as Editor -in-Chief to lead and direct the en t ireproject . An editor ia l staff was then selected of those best qualified forthis type of task. Finally the au thors for the var ious volumes or chapter sor sect ions were chosen from among those exper t s who were int imatelyfamiliar with the var ious fields, and who were able and willing to writ ethe summaries of them. This en t ire staff agreed to remain at work atMIT for six months or more after the work of the Radia t ion Laboratorywas complete. These volumes stand as a monument to this group.These volumes serve as a memoria l to the unnamed hundreds and

thousands of ot her scient ist s, engineers, and others who actually car riedon t he resear ch , development , and engineer ing wor k t he result s of whichare herein descr ibed. There were so many involved in this work and theywor ked so closely t oget her even t hough oft en in widely separ at ed labora-t or ies that it is impossible t o name or even t o know t hose who cont ribut edt o a pa rt icu la r idea or developmen t. On ly cer ta in on es who wrot e r epor t.?or ar t icles have even been ment ioned. But to all those who contr ibu tedin any way to this grea t coopera t ive development en terpr ise, both in thiscountr y and in England, these volumes are dedica ted.


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Preface

T HE preced in g volu mes of t he Radia t ion La bor at or y Ser ies a re su rveysof radar system engineer ing, radar systems of navigat ion, and radarbeacons. Like radar , the long-range system of navigat ion descr ibedin this volume depends upon the t ransmission and recept ion of pulsedradio signals, but it makes use of much lower radio frequencies and doesnot involve reflect ion fr om a t ar get .The Loran system was developed at the Radia t ion Laboratory dur ingWorld War II to meet the needs of the Navy in convoy operat ions and to

provide all-weather navigat ion for a ircra ft by day and night . At theclose of the war , some 70 Loran transmit t ing sta t ions were in opera t ion ,pr oviding night tim e ser vice over 60 million squar e miles, or t hr ee-t ent hsof the sur face of the ear th . About 75,000 shipborne and airborne naviga-t ion receiver -indica tors had been delivered by var ious manufacturers,while the Hydrographic Office had prepared and shipped 2+ millionchar ts t o t he oper at in g agen cies.The purposes of the presen t volume are t o descr ibe the Loran system,

its pr inciples and its equipment , as they existed at the end of the warand to offer suggest ions for their adaptat ion and improvement forcivilian service in t ime of peace. Sin ce elect ron ic t ime mea su remen tsare fully discussed in other volumes of this ser ies, these techniques havenot been t rea ted in deta il here. Similar ly, rela t ively lit t le space has beendevoted to materia l found in the inst ruct ion books for var ious items ofLoran equ ipmen t .Wherever possible, the individual chapters have been writ t en by

those members of the group who have been most closely associa ted withthe mater ial concerned. However , many former members of the groupwho cont ribut ed gr ea t ly t o the development of Loran concept s and equip-ment have been unable to descr ibe their work in this volume. To Mr.Melville Eastham belongs the credit for the organizat ion and adminis-t ra t ion of t he Loran Gr oup dur ing the difficult ear ly days. His leadershipmade the whole development possible and procured the needed suppor tfrom the Services before the mer it of the system had been fully demon-st ra ted. Mr. Donald G. Fink and Professor J . C. St reet made many

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x PREFACEcont r ibut ions and successively assumed the administ ra t ive burdensa fter the ret ir ement of Mr. Eastham and before being called to morer espon sible du ties elsewher e. Throughou t the program Mr. Walter L.Tierney, who managed all field act ivit ies, was a source of st rength to theent ire group. Professor J . A. St ra t ton made valuable preliminary studiesof propagat ion at Loran frequencies, but his knowledge and ta lents weresoon demanded for other purposes. After the Loran system had beensuccessfully demonst ra ted, Mr . Rober t J . Dippy, the or igina tor of theGee system, brought the exper ience of the Brit ish labora tory, TRE, tobear upon Loran problems and helped the group especia lly in improvingthe designs of the receiver -indica tor and the t ransmit ter t imer .The U.S. Coast Guard, Bureau of Shipsj Genera l Elect r ic Company,

Sper ry Gyroscope Company, Fada Radio and Elect r ic Company, RadioEngineer ing Labora tor ies, and the Bar tol Research Foundat ion havekindly supplied photographs and granted permission for their use asillust rat ions of Loran ground sta t ions and equipment . The Hydro-gr aphic Office has gr an ted permission for t he r eproduct ion , as .4ppendixA, of a summary repor t on its Loran program. Thanks are a lso due toMiss Constance Henderson for her aid in prepar ing the drawings and toMiss Cor inne Susman for h er capable ser vice as editor ia l assistant .The publishers have agreed that t en years after the date on whicheach volume of th is ser ies is issued, the copyr igh t thereon shall he relin-

quished, and the work shall become par t of the public domain.THE .ILTTHORS .

CAMBRIDGE, MASS.,October. 1946.


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Contents

FOREWORD BY L. A. DU%IDGE . . . . . . . . . . . . . . . . vii

PREFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..ix

PART I. THE LORAN SYSTEMCHAP. 1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . ..3

NAVI~ATION BY FIXING OF POStTION 31.1 . Pos it ion from Measu rem en t of Two Bea rin gs . 31 .2 . Pos it ion from Meas u remen t of On e Dis ta n ce and On e Bea rin g. 61 .3 . Pos it ion from Measu rem en t of Two Dis ta n ces . . . 814. Pos it ion from Measu rem en t of Two Differen ces of Dis ta n ce. 10

NAVIGATION BY TRACKING AND HOMING . . . . . . . . . 1515,T ra ck in g . . . . . . . . . . . . . . . . . . . . . . . . . 151 .6 , Hom ing......,.. . . . . . . . . . . . . . . . ..161 .7 . Gen era l Compa ris on of Ba s ic Tech n iqu es . . . . . . . . 17

CHAF.2. HISTORY OF LORAN.. . . . . . . . . . . . . . . . . . . 1921. Origin of Pu ls ed Hyperbolic Naviga t ion in th e Un ited Sta tes 192.2 , IYorth At la n t ic Stan da rd Loran Ch a in 262.3 , Eu ropean Sky-wave Syn ch ron ized Loran 302.4 . Loran in th e Ch in a -Bu rma-Ind ia Th ea ter . 3425 , Opera t ion s in th e Pacific . . . . 352.6 , Ch a r t in g an d Tra in in g. 402.7 . Service Area s . . . . . . . . . . . . . . . . . . . . . ..49

CHAP.3 . PRI~CIPLES OF LORAN. . . . . . . . . . . . . . . . 5231.3.2.3.3.3.4.35.3.6.3.7.3.8.3.9.

Time Differen ces an d Lin es of Pos it ion . . . . . . . . . . 52Propaga tion an d Ran ge. . . . . . , . . 59Prin cip les of Opera t ion . . . . 63Loran Geometry : th e Pa ir . . . . . . 70Loran Geom etry: Trip lets , Ch a in s , an d Qu adrila tera ls . . . . . 76Stan da rd Im ran . . . . . . . . . . . . . . . . . . . ...85Sky-wave Syn ch ron ized Loran . . . . . . . . . . . 94Low Frequ en cy Loran . . . . . . . . . . . . . . . . ...97Procedu re in Loran Naviga t ion . . . . . . . . . . . . 102

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xii CONTENTSCEAP.4. FUTURE TRENDS . . . . . . . . . . . . . . . . . . . . . 107

4.1.4.2,43.44.4.5.4.6.47.4.8.

Potent ia l Accuracy and Range,Automatic Data Analysis.Righ t-left In dica tor sThe Lorhumb Line.Rela yed F ixes.Gu ida nce of Pilot less Aircr aftHyperbolic Surveying. .The Curren t Problem. . . .

CEAP.5. PROPAGATION . . . . . . . . . . . . . . . . . . . . . . . 121

INTRODUCTION .,.,,..,. . . . . . . . . . . . . . . .,1215.1 . Grou n d-wave Tran sm is s ion a t 2 Me/ s ee . . . . . . 1215.2 . Sign a l-to-n ois e Factors a t 180 k c/ s ee. . . . . . . 123

LORAN SKY-WAVE TRANSMISSION AT 2 MC/5EC . . . . . . . . . . 12653. T heIonosphere . . . . . . . . . . . . . . . . . . . . ,. 1265.4. Reflect ion . . . . . . . . . . . . . . . . . . . . . . . .. 12955. Absorpt ion . . . . . . . . . . . . . . . . . . . . 1315.6. Elayer Transmission. . . . . . . . . 1335.7. The Loran Sky-wave Delay Curve. . . . . . . 137

LORAN SKY-WAVE TIIANSMISSION ERRORS AT 2 MC/ SEC. . . . . . 13958. Normal Varia t ions in the Sky-wave Delay. . . 1395.9. Sky-wave Accuracy Pat terns . . . . . . 142510, Sporadic E-region Ioniza t ion . . . . 144511. hfagnet ic. act ivity. . . . . . . . . . ,145

LOIIAN TRANSMISSION AT 180 KC/ SEC . 148512. Low Frequency Loran Pulse Shapes 149513, Observa t ion s on th e Experim en ta l Low Frequ en cy Loran Trip let 157

CHAP. 6. METHODS OF COMPCT.4TIO~ OF LORAIY T.4BL13S ANDCHARTS . . . . . . . . . . . . . . . . . . . . . . ...170

6.1.62.63.64.65.66.67.68.

Equations for Distance over the Ear th 170Equations for a Loran Line of Posit ion 173The Three Basic hfethods of Computat ion -177The Standard Inverse }fethod. 179The Direct \ Iethod, Using Plane Hyperbolas 180.4 Mechanical Tracer of Plane Hyperbolas. 186The Direct hfethod, Using Spher ica l Hyperbolas. 188Factors Affect ing the Correctness of Computed Loran TimeDifferences ..,...... 192


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CONTENTS .-..

PART II. LORAN EQUIPMENTCHAP. 7. TIMERS . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

7.1. General Requirements . . . . . . . . . 1977.2. Timer Models A, B,and B-1. . . . . . . . . . . .199

MoDELCI TIMER . . . . . . . . . . . . . . . . . . . . . . . .. 2057 .3 . Gen era l Des cr ip t ion of Timer Models C, Cl, a n d UJ . . 2057 .4 . Block Diagram of Model C-1 Timer . . . 20775. Model C-l Oscilla tor . . . . .2157 .6 . ModeIC-l Divider Un it .. . . . . . . . . . . . . . ...2197.7 . Model C-l Selector Ln it . . . . . . . . .22678. Model C-l Syn ch ron izer . . . . . . . . . . . .229

MoDELLE-I TIMER . . . . . . . . . . . . . . . . . . . . . . . .. 2327.9 . Gen era l Des cr ip t ion of Model UE1 Timer . . . . . . . . 2327.10. Model UE-10scilla tor . . . . . . . . .237711 . Model UE-1 Ph as e-con trol Un it . . . . . . . . . . 2407.12. Model UE-l Receiver . . . . . . . . . . . .2437.13 . Model LTE1 Syn ch ron izer . . . . . . . . . . . . . . 245

LOW FREQUENCY TIMER . . . . . . . . . . . . . . . . . . . . . .. 2497.14. Gen era l Requ irem en ts . . . . . . 2497.15 . Block Diagram of Low Frequ en cy Timer . . . . 253

CHAF. 8. SWITCHING EQUIPMIl~T. . 25881. General Requirements 2588.2. The Switching Equipment Used with Model A, B, and B-1 Timers 26183. Ifodel C-1 Switching Equipment . 2618.4, Model UM Switching Equipment . 26585. Low Frequency Switching Equipment . 271

CHAP. 9. TR.4XSM1TTERS . . . . . . . . . . . . . . . . . . . . . . 27591. General Requirements . . . . . . . 2759.2. Standard Loran Transmit ters . . . . . . . . 27793. Transmit ter Test Oscilloscope. . . . . . 28594. Low Frequency Transmit ter Requirements . . . . . . 2889.5. Low Frequency Transmit ter . . . . . . . . 291

CHAF.1O. AIfTENXA SlSTEMS . . . . . . . . . . . . . . . . . ..3o1101. Requirements for Ground-sta t ion Antennas 30110.2. Antenna Coupling LTnits 303103. Predict ion and Simulat ion of Antmura Character ist ics 314104. Ground-sta t ion .kntennas for 2-31c/sec Loran 323105. Ground-sta t ion .4ntennas for 180-kc/sec Luran. 329


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xiv CONTENTS(?~AF. 11 . RECEIVER-INDICATORS. . . . . . . . . . . . 345

SEIPBOAXD RECEIVER-INDICATORS. . . . . , . 34511 .1 . Requ irem en ts and Genera l Descr ipt ion . . . . . . . 34511.2. Model DAS-1 Receiver -indica tor . . . . . . . . 35o11.3. Model DASL2 Receiver -indica tor , . . . . 355114. Model DBE Receiver -indica tor . . . . . 358

AIREOFtNE RECEIVEn -INDICATOrIS . . . 36311 .5 . Gen era l Des cr ip t ion an d Tren ds in Des ign . . . . 36311 .6 . Model AN/ APh 7-4 Receiver-in d ica tor . 36711 .7 . Model AN/ APN-9 Receiver -ir rd ica tor . 374

TEST AND TRAINING EQUXIWENT. . 38111.8 . Pu ls e-s ign a l G en era tors . 38111.9 . Th e Su pers on ic Tra in er . 382

CHAF. 12, SPECIAL TECHNIQUES AND MEASUREMENTS . . . 386121.122.12.3.12.4.12.5.126.

APPENDIX A.

APPEND= B.APPENDIX C.

Receiver -des ign Notes .. . ,386Differen t ia l-ga in Pr in cip les 390Pu ls e-s ign a l Gen era tor . 395Pu ls e-ban dwid th Mea su rem en ts 396Spect ru m Meas u rem en ts 397Cycle-m a tch in g Receivers . 3Y8THE LORAN PROGRAM IN THE HYDROGRAPHIC

OFFICE, .,..,.....,.. . . . . . . . ...403LORAN GROUND STATIONS. 419DEMONSTRATIONS CONCERNING THE GEOMETI1 l- OFLORAN LINES..,....,., ., . . . . . . ...425

Cl. The Factor of Geometr ica l P recision 425C2.TheP robableEllipse. 427C3.TheP robableEr rorofa Fix : :429

APPENDIX D. DETERMINATION OF ERRORS IN THE POSITIONS OFLORAN TRANSMITTING STATIONS. 432

BIBLIOGRAPHY, . . . . . . . .457

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . ...469

mit radiation lab series, v4, long range navigation (loran) - front matter, preface, contents

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