IEEE 1260-1996 - IEEE Guide on the Prediction, Measurement, and Analysis of AM Broadcast Reradiation by Power Lines.pdf

1、Important NoticeThis document is a copyrighted IEEE Standard. You may use this document inconnection with IEEE Standards development/revision activities and/or forpersonal use relating to your own work. No further reproduction or distributionof this document is permitted without the express written

2、permission of IEEEStandards Activities, 445 Hoes Lane, P.O. Box 1331, Piscataway, NJ 08855-1331.Recognized as anAmerican National Standard (ANSI)The Institute of Electrical and Electronics Engineers, Inc.345 East 47th Street, New York, NY 10017-2394, USACopyright 1996 by the Institute of Electrical

3、and Electronics Engineers, Inc.All rights reserved. Published 1996. Printed in the United States of America.ISBN 1-55937-722-4No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher.IEEE Std 1260

4、-1996IEEE Guide on the Prediction, Measurement, and Analysis of AM Broadcast Reradiation by Power LinesSponsorTransmission and Distribution Committeeof theIEEE Power Engineering SocietyApproved 14 February 1996IEEE Standards BoardApproved 16 July 1996American National Standards InstituteAbstract: A

5、set of procedures to be followed to cope with reradiation of AM broadcast signals frompower lines and other large metallic structures is provided. Reradiation may be described as elec-tromagnetic waves radiated from a structure that has parasitically picked up a signal from the envi-ronment. A simpl

6、ified prediction technique called a survey is described to determine whichstructures could possibly cause a problem. Guidelines for measurements and data analysis are in-cluded.Keywords: AM broadcast, interference prediction, measurement, power lines, reradiationIEEE Standards documents are develope

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18、ponsible for identifying all patents forwhich a license may be required by an IEEE standard or for conducting inquiries intothe legal validity or scope of those patents that are brought to its attention.iiiIntroduction(This introduction is not a part of IEEE Std 1260-1996, IEEE Guide on the Predicti

19、on, Measurement, and Analysis ofAM Broadcast Reradiation by Power Lines.)This guide provides a set of procedures to be followed to cope with reradiation of AM broadcast signalsfrom power lines and other large metallic structures. Reradiation may be described as electromagnetic wavesradiated from a s

20、tructure that has parasitically picked up a signal from the environment. A simplified predic-tion technique called a survey is described to determine which structures could possibly cause a problem.Guidelines for measurements and data analysis are included.While the procedures listed in this guide m

21、ay be applicable to reradiation problems from other medium fre-quency (MF) sources, such as navigation beacons, they are not intended to be applied to reradiation prob-lems from higher frequency sources, such as television broadcast signals. It is anticipated that this guide willbe used by owners of

22、 potentially reradiating structures, and radio stations. It is not designed to be applied aslegal evidence of harmful effects of a reradiating structure upon an AM broadcasting station.In some political jurisdictions, the government regulatory or licensing authority has defined specific proce-dures

23、for the determination of radiation patterns of medium wave antenna systems. Some of these proce-dures are also contained in international treaties and agreements, and as such are binding on the licensees ofthe signatory jurisdictions. When there is agreement between the party or parties who are lice

24、nsed to operatethe medium wave antenna system(s) in question and the parties proposing construction of potential reradiat-ing structures, the procedures of the responsible government agency or authority shall have precedence overthe method outlined in this guide.Rick C. Madge, ChairOther contributor

25、s include:The following persons were on the balloting committee:Thomas J. McDermott Robert G. Olsen James R. StewartRod S. BaishikiMagda HammamJim HatfieldAttila PaldiJean ProvostMichael A. ReavisMark A. TilstonTom YoungJames E. ApplequistJoseph F. BuchJames J. BurkeVernon L. ChartierFrank A. Denbro

26、ckWilliam E. FeeroI. S. GrantWasyl JanischewskyjJohn G. KappenmanGeorge G. KaradyNestor KolcioJoe H. MalloryP. Sarma MaruvadaThomas J. McDermottFranklin D. MyersGeorge B. NilesStig L. NilssonR. J. PiwkoW. Edward ReidB. R. ShperlingJames R. StewartivWhen the IEEE Standards Board approved this guide o

27、n 14 February 1996, it had the followingmembership:Donald C. Loughry, Chair Richard J. Holleman, Vice ChairAndrew G. Salem, Secretary*Member EmeritusAlso included are the following nonvoting IEEE Standards Board liaisons:Satish K. AggarwalAlan H. CooksonChester C. TaylorMary Lynne NielsenIEEE Standa

28、rds Project EditorGilles A. BarilClyde R. CampJoseph A. CannatelliStephen L. DiamondHarold E. EpsteinDonald C. FleckensteinJay Forster*Donald N. HeirmanBen C. JohnsonE. G. “Al” KienerJoseph L. Koepfinger*Lawrence V. McCallL. Bruce McClungMarco W. MigliaroMary Lou PadgettJohn W. PopeJose R. RamosArth

29、ur K. ReillyRonald H. ReimerGary S. RobinsonIngo RschJohn S. RyanChee Kiow TanLeonard L. TrippHoward L. Wolfmanv1. Overview 12. References 23. Definitions . 24. Background . 44.1 Description. . 44.2 Proof of performance . . 55. AM reradiation guidelines: general procedures. . 65.1 Potential reradiat

30、ion problems . . 65.2 Existing reradiation problems . 66. Reradiation prediction techniques . . 76.1 Computer programs . . 76.2 Survey technique . 87. Field strength measurements . . 97.1 Circular measurements 107.2 Ratio measurements . 117.3 Test point selection criteria 127.4 Near-Field measuremen

31、ts 137.5 Factors affecting measurements.148. Field strength analysis . 148.1 Individual test analysiscircular measurements 148.2 Individual test analysisratio measurements . 158.3 Signal fluctuation analysis . 168.4 Seasonal fluctuation analysis . 168.5 Before versus after analysiscircular measureme

32、nts . 178.6 Before versus after analysisratio measurements 188.7 After-construction only analysiscircular measurements 198.8 After-construction only analysisratio measurements. 219. Structure reradiation measurements. 229.1 Base current measurements . 229.2 Structure field strength readings 239.3 Sc

33、ale-Model measurements . 2310. Remedial measures or alternatives 2310.1 Power-Line tower skywire insulation 2310.2 Power-Line tower detuning stubs 2410.3 Power-Line skywire stubs 2610.4 Alternatives 2611. Bibliography 27viAnnex A . 29(informative)Reradiation prediction computer programs. 29Annex B .

34、 30(informative)Reradiation survey example 30Annex C . 31(informative)Before versus aftercircular measurement example . 31C.1 Individual test analysis examplecircular measurements 32C.2 Typical signal fluctuation example 34C.3 Seasonal signal fluctuation example 34C.4 Before-versus-after analysis ex

35、ample 35Annex D (informative) Groundwave propagation loss computer program. 391IEEE Guide on the Prediction, Measurement, and Analysis of AM Broadcast Reradiation by Power Lines1. OverviewThis guide provides a set of procedures to be followed to cope with reradiation of AM broadcast signalsfrom powe

36、r lines and other large metallic structures. An AM broadcast array is carefully constructed to radi-ate strongly towards listeners and weakly in directions where interference to other stations could result.Reradiation can occur when the broadcasted signals are parasitically picked up by a large meta

37、llic structureand then rebroadcasted, or reradiated, from that structure. This can result in a decrease in signal towards lis-tening areas and an increase in signal in protected directions. The process of predicting, measuring, and ana-lyzing the interference is complex and nontrivial, necessitating

38、 this guide.This guide is divided into the following sections: interference prediction and limitations, guidelines for tak-ing meaningful field strength measurements, methods of analysing the field strength measurements, andshort sections on the application and verification of remedial measures. A s

39、eries of annexes accompany theguide in order to illustrate the complex analysis.While the procedures listed in this guide may be applicable to reradiation problems from other medium fre-quency (MF) sources, such as navigation beacons, they are not intended to be applied to reradiation prob-lems from

40、 higher frequency sources, such as television broadcast signals. It is anticipated that this guide willbe used by owners of potentially reradiating structures, and radio stations. It is not designed to be applied aslegal evidence of harmful effects of a reradiating structure upon an AM broadcasting

41、station.In some political jurisdictions, the government regulatory or licensing authority has defined specific proce-dures for the determination of radiation patterns of medium wave antenna systems. Some of these proce-dures are also contained in international treaties and agreements, and as such ar

42、e binding on the licensees ofthe signatory jurisdictions. When there is agreement between the party or parties who are licensed to operatethe medium wave antenna system(s) in question and the parties proposing construction of potential reradiat-ing structures, the procedures of the responsible gover

43、nment agency or authority shall have precedence overthe method outlined in this guide.IEEEStd 1260-1996 IEEE GUIDE ON THE PREDICTION, MEASUREMENT, AND ANALYSIS22. ReferencesThis guide shall be used in conjunction with the following publications. If the following publications aresuperseded by an appr

44、oved revision, the revision shall apply.IEEE Std 100-1992, The New IEEE Standard Dictionary of Electrical and Electronics Terms (ANSI).1ANSI/IEEE Std 268-1992, American National Standard for Metric Practice.IEEE Std C95.1-1991, IEEE Standard Safety Levels with Respect to Human Exposure to Radio Freq

45、uencyElectromagnetic Fields, 3 kHz to 300 GHz (ANSI).3. DefinitionsMany of the terms used in this guide can be found in IEEE Std 100-1992. The following definitions areeither not included in IEEE Std 100-1992 or are specific definitions modified from the general definition tofit this topic more accu

46、rately.3.1 AM broadcast array: One or more towers fed the same broadcast signal but at different current levelsand with different delays. By carefully choosing the height, location, current level, and delay for each tower,a far-field pattern can be constructed to broadcast strongly in some direction

47、s and weakly in others.3.2 amplitude modulation (AM): Modulation in which the amplitude of a carrier is caused to depart fromits reference value by an amount proportional to the instantaneous value of the modulating wave.3.3 azimuth: The angle between a horizontal reference direction (usually true n

48、orth) and the horizontal pro-jection of the direction of interest, usually measured clockwise.3.4 coverage area: The area surrounding the broadcast array that is within the signal strength contour thatprovides adequate reception.3.5 detuners: Devices attached to a structure that alter the impedance

49、at the connection point such that aminimum of current at the design frequency flows in the structure. Syn: detuning stub, tuning stub.3.6 far-field radiation pattern: Any radiation pattern obtained in the far field of an antenna array.3.7 far-field region: That region of the field of an antenna array where the angular field distribution is essen-tially independent of the distance from the center of the array. A general far-field approximation is 2d2/,where d is the largest separation between elements in the array.3.8 field strength: The magnitude of the electric field vector.3.9 fi