183
1 INTRODUCTION
Ecology is the science, the branch of biology that
studiestherelationshipsbetweenthe organisms and
theenvironmentandtherelationshipsbetweenliving
organisms themselves. The definitions of ecology
generally express that the subject of studying the
ecology is a living matter on different stages of
organization,itsexternalenvironmentwhichconsists
ofopenBiosystems[TrnkaA.,PeterkovaP.&Prokop
P.2006].Atthesameti
me,studiedobjectsofecology
maybeonthedifferentbiologicallevel.Elementsof
the environment are divided into biotic, abiotic and
abiotic‐biotic. The biotic elements include living
organisms(plants,animals,humans), an ab
ioticpart
consistsoftheinanimateelements(air,water,rocks)
and abiotic‐biotic component consists of a
combinationofanimateandinanimatecomponents.
Electromagnetic radiation is characterized as a
transfer of energy in the form of electromagnetic
waves. The individual electromagnetic wave is
therefore a locally formed change in the
electromagneticfield.
El
ectromagnetic smog is increasingly being
mentioned in respect of electromagnetic radiationto
the environment. Electromagnetic smog is produced
inadensetangleofelectromagneticfields,mostlyin
densely populated areas or near sources of
electromagnetic radiation, where several sources
simultaneouslyoccur.
Aviation electronic safety technology as a source
ofelectromagneticradiationisapotentia
lrisk[Cekan
P.,HovanecM.& Sabo,J.2016]tothesurrounding
ecosystememitscontinuousradiationwavesintothe
surroundingspace[Vagner,J.,Jencova,E.2014].Itis
therefore necessary to investigate the effects of high
frequency energy radiation on the surrounding
environmentand look foropport
unities to protectit
against this radiation [Tobisova, A., Pappova, E.
2014].
Protection Against High-Frequency Radiation of
Aviation Electronic Support Systems Used in Air
Transport
M.Dzunda,D.Cekanova,L.Cobirka,P.Zak&P.Dzurovcin
TechnicalUniversityofKosice,Kosice,Slovakia
ABSTRACT:Theaimoftheart
icleistoanalyzetheimpactofelectromagneticradiationofaviationelectronic
support systems on environmental segments and a human organism. We were looking for effects of
electromagneticradiationoninhabitantsandenvironmentinthevicinityofairportradars.Weaccomplished
mea
suring and found out the level of radiation harmfulness of electromagnetic radiation sources. In the
conclusionwesuggesttoeliminatethenegativeimpactofelectromagneticradiationonthehumanorganism.
At the same time we present the ways how workers, performing their jobs in the vicinity of strong
electromagneticradiationsource,canprotectthemselvesincompliancewithlegislat
iveoftheSlovakRepublic.
We have proposed some possibilities of protection for workers who work close to a strong source of
electromagneticradiation.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 12
Number 1
March 2018
DOI:10.12716/1001.12.01.21
184
2 OVERVIEWOFAIRELECTRONICSAFETY
TECHNOLOGY
Air Traffic Services of the SR are using
communication, radio navigation and radar systems
tocontrolairtraffic[Gajdos,J.,Socha,L.&Mihalcova,
B.2014,Socha,V.2016].Communicationsystemsare
operatingatfrequenciesof100‐150MHz.Theoutput
powerof
thesesystemsis5.0to20.0W.Theprimary
surveillance radar is operating at frequencies of 2‐4
GHz. Transmitted power of these systems is 14‐25
kW. The power of older types of radar is several
hundredkW.Secondaryradarsoperateatfrequencies
of1030MHzand1090MHz.
Transmissionpowerof
adeviceisabout2kW[Melnikova,L.,Cibereova,J.&
Korba,P.2016].
NDB navigation systems and ADF work on the
frequency kHz 200‐525. Transmission power of a
deviceis25‐50W.VORoperatesonafrequencyMHz
108‐112. Transmission power has a 25‐100
W. DME
measures the distance and works on the frequency
960‐1215 MHz. Transmission power of a device is
100W.
TheILSprecisionapproach:
Localizer LLZ (device frequencies: 108‐112 MHz,
transmissionpower2W)
GPGlidepathbeacon(devicefrequencies:328.6to
335.4MHz,transmissionpower2W)
VHF marker beacons (frequency 75 MHz,
transmissionpower3W)
3 MEASUREMENTOFTHEELECTRICFIELDIN
VELKAIDA
Near the village Velka Ida in the place with the
coordinates N48º 36ʹ51,9ʺE21 º 08ʹ47.14ʺ we made
measurements of the primary radar electric field
(PRL).
Themeasuringinstrumentswere
usedasfollows:
SpectrumAnalyzer‐AdvantestR3271A,SerialNo
.:J001158
Antenna‐EMCO 3115 DOUBLE GUIDE RIDGE
HORN,SerialNo.:4974
Attenuator‐50Ω/36db
Coaxial cable with N connector‐50Ω Coax 3m,
typeM17/75RG‐214
Generator‐220V/50Hz:HONDA
EM30PC
Figure1. The connection diagram of devices during the
measurement
3.1 Measuredvalues
On the site we observed the field strength of six
channels, and we reached the following measured
values:
Table1.Thevaluesofmeasurement
_______________________________________________
Frequency MeasuredValues Intensity
[GHz] [mV][V.m‐1]
_______________________________________________
2,709214,27,98
2,829807,831,37
2,95569,22,81
2,9784398,0179,84
3,016699,528,99
3,098741,031,58
_______________________________________________
Thevaluesoftheelectricfieldareintherangeof
2.81 to 179.84 W / m. The measured values are the
peakvaluesoftheelectricfield.
Allowedvaluesoftheelectricfieldareassignedin
the decree of the Slovak Republic Government No.
329ontheminimumhealthand
safetyrequirements
protectingworkersfromthe
risksrelatedtoexposure
to electromagnetic fields. The action values are
expressed in effective values for continuous
exposure[PavolováH.&TobisováA.2013].
Allowedvaluesoftheexposuretotheelectricfield
forthepopulationaresetoutintheDecreeNo.534of
theMinistryofHealthofthe
SlovakRepubliconthe
details of the requirements for sources of
electromagnetic radiation and limits for citizens’
exposure to electromagnetic radiation in the
environment. The action va lues are expressed in
effectivevaluesforcontinuousexposure.
Weevaluatedtheelectricfieldimpactinorderto
protect workers and citizens in accordance
with the
SlovakGovernmentregulationsNo.329/2007andthe
MinistryofHealthDecreeNo.534/2007.
The value of the intensity of the electromagnetic
field for continuous exposure of employees in the
frequencyrangeof2GHz‐300GHzis137V/m.The
specified value for continuous exposure of the
population in the same frequency range is 61 V /
m
[Sebescakova, I., Rozenberg, R. & Melnikova, L.
2013].
3.2 Resultsofmeasuring
Theeffectivevalueinthemeasuringpointisequalto
the square root ofthe time average ofthe squareof
thefieldstrengthE(t)overtheperiod:
E
ef=Eef=((1/T)∫E(t)dt)
0,5
,
where in T = 1/f‐is the period of the oscillating
parameters, and f is the frequency (s
‐1
= Hz). After
substitutingintotheaboveequationwecanformulate
E
ef,asfollows:
E
ef=0,707.Ešp
After an analysis of how the radar works (PRL)
closetoVelkaIda,itcanbeassumedthatthepulsed
electromagnetic field has a pulse character with a
width of 0.9 to 3.1 microseconds and a repetition
periodof300‐1275Hz.
Themaximummeasuredvalueoftheelectricfield
in
the introduced mea s uring point is equal to Ešp =
179.84 V/m. The maximum effective value of the
electricfieldatthe measuring point isequalto E
ef=
185
127.14 V/m. After comparing the measured effective
valuesoftheelectricfieldatallfrequencieswiththe
maximumpermissibleactionvaluesfortheexposure
ofemployees,wehavefoundoutthatthemeasured
valuesdonotexceedthemaximumpermittedlevels.
Ifthereisasimultaneousexposuretofieldsfrom
severalsourceswithdifferentfrequencies,thethermal
effect applying at frequencies exceeding 100 MHz
shall not exceed the action value if the followed
inequalityisvalid:
1300
2
2
ii,
100 1
//1
MHz GHz
Li
kHz f MHz
Ec EE
whereEidenotestheelectricfieldwithafrequencyof
ʺiʺ,E
L,iisactionvalueoftheelectricfieldforthei‐th
frequency, c = 610.10
6
/f , V/m. When measuring we
found out the presence of an electric field with a
frequencygreaterthan1.0MHz,sothefirstmember
of an inequality on the left side equals zero. By
substitutingweobtaintheinequalityof0.93<1.0.By
calculation, we have confirmed that the heat
of an
electricfieldinthemeasurementdoesnotexceedthe
actionvalue.
Themaximummeasuredpeakvalueoftheelectric
fieldoftheE
šp=179.84V/mdoesnotexceed32times
the allowable action field intensity equal to E
L = 61
V/m.
The radiant heat exposure to an electric field,
shorterthanthosedeterminedforcentring,oraseries
ofshort‐termexposuresactingduringthetimeshorter
than designed forcentring doesnʹt exceedthe action
value if the exposure timeʺt
iʺand the measured
levels of fields Ei in the range from 100 kHz to 10
GHzmeettheinequality:
22
,
6
ii Li
Et E
wheretiisthetimeofthei‐thexposureexpressedin
minutes.For i‐th exposure during the 6 minute
interval, we determined the parameters of the
transmittedsignalPRL.Thewidthofthetransmitted
pulsePRLis3,1μs,repetitionperiodof1275Hz.Over
aperiodof6minutes
tiwillbeequalto0.0237.After
substitutingintotherelationship(4)wehavereceived
theinequality
417.40<22326.0.
Theinequalityismet.Weherebyconfirmthatthe
radiant heat exposure to an electric field does not
exceedtheactionvaluesforthefield.
In the range of frequencies from 100 kHz to 300
GHz,weassessedtheeffectoffieldtemperaturewith
regardtoidentifiedactionlevelsduring the
exposure
to an electric field and magnetic field of the same
frequency or different frequencies (according to the
Decree 534/2007 Z.z.). Substituting the parameters
intoarelationship,wegettheinequality:
2.5.10‐3<1
Radiantheatatthepointofmeasurementdoesnot
exceedtheactionvaluebecausetheabovementioned
inequalityhasbeenmet.
4 CONCLUSION
The measurement results obtained by the analysis
demonstratethattheeffectoftheelectricfieldinthe
vicinityofVelkaIda,whichisinthe
rangeof2.709to
3.098 GHz, does not exceed the action values for
exposureofworkersandthecitizens.Eventhough,it
is appropriate to be protected from the high‐
frequency radiation [Cekan P., Korba P. & Sabo J.
2014].
The basic types of protection from non‐ionizing
electromagneticradiation:
distance,
time,
shieldingoftheworkplace,
protectiveworkequipment
Protectionmethods:
Protectionbydistance
The workplace close to the electromagnetic
radiation should be kept as far away from this
resource as possible. The workplace should not
misssignallingandwarningthattheoneiscloseto
theelectromagneticfield.
Protectiontime
Protectiontimemeanstheexposureofworkersto
electromagneticfieldsonlyforacertainperiodof
time, to avoid possible serious consequences of
prolonged exposure close to the source field.
Likewise,inthecaseofmobilephones,oneofthe
recommendationstominimizethe
consequencesof
the radiation is to shorten the talk time to a
minimum.
Personalprotectiveequipment
Personalprotectiveequipmentforworkersisused
incaseswherethereisperhapsnootherprotection
oftheabove.Mostoftenitisacompletesuitefor
the protection of the entire body (suit,
helmet,
glovesandboots).Theymayalsobeindependent
partsofclothingforindividualpartsofthehuman
body.Theymustbemadeofmaterialsthatdonot
preventworkerʹsfreemovement.
Protectiveshieldingoftheworkplace
Workplace protection against electromagnetic
radiationisperformedina similarmanner
asthe
shieldingforradiation.Protectivesheets,foilsand
network in this case are installed in walls of a
particularjob.Thereareotherwaysofprotecting
thespacefromradiationsuchasdifferentcoatings
andsprayingwithmetalparticles,windowfilms,
curtains and blinds containing metals. Protection
byshieldingthe
workplacewasusedinplanning
theconstructionworksofalogisticscenter(LC)in
Velka Ida. The [Džunda, M. 2010.] analyzed in
detailsthepossibilityofprotectingpeopleagainst
the radar high‐frequency radiation, which is
located in Velka Ida. One possible way of
protectionagainsttheradarhighfrequency
energy
istobuildaprotectivewallwhichwouldprevent
the penetration of radiation into space in which
people move. The protective wall, which was
constructednearVelkaIda,isshowninFig.2.
186
Figure2.TheprotectivewallconstructedinVelkaIda.
The height of the protective wall is 4.5 m and is
located in front of the buildings of LC on a line
perpendiculartotheconnectinglinebetweenLCand
RadarinVelka Ida. Fig.2 clearly showsthat such a
protectivewallprovidessufficientprotectionagainst
radarHFradiationnear
VelkaIda.
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