n.a. frissell , g. perry , e.s. miller m. moses , and a....

[email protected] 21July2015

N.A.Frissell1,G.Perry2,E.S.Miller3,M.Moses1,andA.Shovkoplyas4

1VirginiaTech2UniversityofCalgary

3JohnsHopkinsUniversityAppliedPhysicsLaboratory4AfreetSoftware


TheCASSIOPE(CAScade,Smallsat andIOnospheric PolarExplorer)satellitewaslaunchedonSeptember29, 2013bySpacex’s Falcon9v1.1.CASSIOPEisaCanadiandesignedandbuiltsatellite,withtwoprimarytasks:atelecommunicationstechnologydemonstration,andasciencemission. Thelatteriscarriedoutbye-POP(theenhancedPolarOutflowProbe),asuiteof8instrumentsonboardCASSIOPE,taskedwithstudyingtheoutflowofplasmafromtheionosphereintothenearEarthgeospace.OneofePOP’s 8instruments,theRRI(RadioReceiverInstrument),measuresnaturallyandartificiallygeneratedradiowavesbetween10Hzand18MHz. Itemploys4,3-mmonopoleantennas,whicharecombinedtogiveacross-dipoleconfiguration. RRIsamplesat62.5kHzontwochannels,overa30kHzbandwidth.OnesciencetargetforRRIistostudyHFpropagationintheionosphere. Ithasbeenusedinconjunctionwithmultipleradarfacilitieslocatedaroundtheworld,andwewanttotestthefeasibilityofaddingtheamateurradiocommunityintothemix.WewereexcitedtolearnthattheARRLisconductingafield-day,happeningatthesametimethatCASSIOPEisnearingperigeeinitsorbit. Thisweekendthespacecraftwillbeatapproximately375kmaltitude,overthecontinentalUnitedStates.Wehavemanagedtofreeupafewminutesoftimeonthesatelliteandourgoalsareto:first,determinewhetherornotwecandetecttransmissionsduringthefieldday,andsecondly, decodethetransmissionsanddeterminetheirorigin. CASSIOPEisfundedbytheCanadianSpaceAgency,andoperatedbyacommunityofCanadianandAmericanscientistsfromoveradozeninstitutions. ItsoperationsheadquartersislocatedattheUniversityofCalgary.


• AmericanRadioRelayLeague(ARRL)-sponsoredamateurradiooperatingevent.

• Objective:ContactasmanyUSorCanadianStationsasPossibleina24HourPeriod,primarilyonHF(3-30MHz)Bands

• Stationsareencouragedtooperateremotelytosimulateemergencyconditions.

• 27June20151800UT– 28June20152059UT(AlwaysFourthFullWeekendinJune)

• 2687StationsParticipatedin2014(http://www.arrl.org/results-database?event_id=58360)


NorthtoSouthPasswithRRIReceivingfrom0116to0118UT28June2015from3.510to3.540MHzand7.010to7.040MHz


• Strongsignalsobservedon7MHzBandfrom~0116:15– 0116:40UT(~43.7˚Nto42.1˚N).

• Signalsdropoffsuddenlyafterthispoint.

• Fewsignalsseenin3.5MHzband.

• Signalsappearagainat0117:52UTinboth3.5and7MHz.

Dipole Mode, GAIN1 High, GAIN2 High, GAIN3 High, GAIN4 HighInputs: Channel 1 - I1, Channel 2 - Q1, Channel 3 - I3, Channel 4 - Q3

3.510

3.515

3.520

3.525

3.530

3.535

3.540

Inpu

t A F

req

(MH

z)

MaxAV 30.

-20

-12

-3

5

13

22

30

Ant.

Volta

ge, A

V, (2

0log

(µV p

p))

7.010

7.015

7.020

7.025

7.030

7.035

7.040

Inpu

t B F

req

(MH

z)

01:16:14.6 01:16:34.1 01:16:53.6 01:17:13.1 01:17:32.6 01:17:52.1 01:18:11.5

MaxAV 60.

-20

-7

7

20

33

47

60

Ant.

Volta

ge, A

V, (2

0log

(µV p

p))

UTALT 386.3 381.0 375.9 371.0 366.4 362.0 357.8LAT 43.7 42.4 41.1 39.8 38.5 37.3 35.9LON -88.1 -87.8 -87.5 -87.2 -87.0 -86.7 -86.5MLT 19.3 19.4 19.4 19.4 19.5 19.5 19.5

NumPointsPerSpectrum 625

June 28, 2015e-POP RRI

Source session filenames: RRI_20150628_011614_011644_0000F_4589.lv0 toRRI_20150628_011745_011811_0000F_5E4F.lv0

Produced by RRIQL v1.2


• 7MHzsignalsdecodedaurally

• 23StationsIdentified

• MostfromIllinois,Wisconsin,Indiana

• SpecialWAVFilecanbeplayedinCWSkimmer

“DEWR9YQSL1DWI”http://www.dxatlas.com/CwSkimmer/

[email protected] 21July2015https://www.google.com/maps/d/edit?mid=zOoXJW2oSyUs.kaAuCqAzWRdQ&usp=sharing


Frequency Call ReportedSection QRZState Grid Lat Lon Name

7005.18 N4ILDOESN'TCOUNT- STATIONINQSO TracyLMelton

7005.58 W1HPDOESN'TCOUNT- STATIONINQSO

7009.49 W9NE IL EN51ts 41.760594 -88.344504 FOXRIVERRADIOLEAGUEINC

7011.38 K8CAD MI EN74jcWEXAUKEEAMATEURRADIOCLUB

7011.68 W9PN WI WI EN52mr DOUGLASRSPEER

7014.53 W9MVA WI EN43jt 43.831719 -91.17135MISSISSIPPIVALLEYAMATEURRADIOASSO

7022.27 W9TE IN EN71jb 41.054182 -85.241697 FORTWAYNERADIOCLUB7025.33 WR9Y WI WI EN53va RICHARDBARCZ7026.76 W9JP IN IN EM69xt 39.802959 -86.019672 INDIANAPOLISRADIOCLUB

7026.76 W9SW IL IL EN61cuCHICAGOSUBURBANRADIOASSOCIATION

7032.5 K9EAM WI WI EN54xiGREENBAYMIKEANDKEYCLUBINC

7032.55 W0SRC MO EM48uo 38.586076 -90.295323

STLOUISANDSUBURBANRADIOCLUB

7033.49 K9ESV IL EN52tgMcHenryCountyRACESAssociation

7033.49 WB6FDY IL EN62ag RONALDSLISIECKI

7036.1 K8SCH OH EM79qcOHKYINAMATEURRADIOSOCIETY INC

7036.1 N9EZ MI EN56al JohnAForslund7037.64 N4ZZ TN TN EM66pe DONALDHBINKLEY7039.05 N9SAB IL EN62ci 42.372264 -87.830369TimothyPOrtiz7039.67 N3AD PA FN20ib ALANJDONZIGER7040.67 KW8N OH EN81xi ROBERTBHAYES7043.39 K8ED MI EN82io 42.606733 -83.328708MARKSHAW7044.83 K9OR IL EN62da 42.030327 -87.688909RANDALLBBROTHERS

7044.83 K2MKVery faint;onlyidentifiedbecauseK9ORgavecall NJ FM29nw 39.939637 -74.881503MichaelHKravitz


• During the2minutepass,10oftheePOP identifiedtransmitterswerespottedby26RBNreceivers.

• PlottedRBNreceiverswithoutpathswereactiveduring the2minutes,butdidnotspottheePOPidentifiedstations.


• Theplasmafrequencyisproportionaltothesquarerootoftheionosphericelectrondensity.

• IfthesatellitefliesaboveanionosphericlayerwithaplasmafrequencyhigherthantheHFsignalstransmittedfromtheground,thesignalswillbeshieldedfromthesatellite.

• Webelievethesatellitepassesthrougharegionofincreasesplasmadensityandfrequency.Whentheplasmafrequencyofallionosphericlayersbelowthesatelliteislowerthan7MHz,signalsareobserved.Oncethesatellitepassestoaregionwherealoweraltitudeionosphericlayerhasaplasmafrequencygreaterthan7MHz,thesignalsareshielded.


• FoF2=6.950MHzatMillstoneHillat0115UT,whichisclosetoCASSIOPEtrajectory.

• Additional,nearbyionosondedataisnotcurrentlyavailable.

Source:http://umlcar.uml.edu/DIDBase/[ReinischandGalkin,2011]


• Aquick-lookDXAtlas/InternationalReferenceIonosphere(IRI)2000[Bilitza,2001]PredictionofFoF2showsapositiveFoF2gradientalongthesatellitetrajectory.

• Thissupportstheplasmafrequencyfilteringhypothesis.

http://www.dxatlas.com/DxAtlas/


• TheRRIInstrumentonCASSIOPESatellitelistenedtoradiofrequenciesinthe3.5and7MHzamateurradiobandsduringalarge-scaleoperatingeventon28June2015.

• TheRRIcouldsuccessfullydetectamateurradiotransmissionsat7MHz,buttheyendedabruptlyafterapproximately20seconds.

• Thisdatasuggeststhatthesatellitemovedintoaregionwhereanionosphericlayerbelowthesatellitehadaplasmafrequencygreaterthan7MHz,therebyshieldingincomingsignals.

• Additionalmodelingandanalysisworkshouldbecompletedtofurthersupportthisconclusion.

• ThisexperimentdemonstratesthefeasibilityofconductingfurtherHFamateurradio-satellitecoordinatedstudies.


• RRIandCASSIOPE/ePOP arefundedbytheCanadianSpaceAgency.CASSIOPEisoperatedbyacommunityofCanadianandUSscientistsfrommorethanadozeninstitutions.ItsoperationsheadquartersislocatedattheUniversityofCalgary

• TheauthorsacknowledgeB.W.ReinischoftheUniversityofMassachusettsLowellformakingtheseionogram imagesavailable.


Bilitza,D.(2001),InternationalReferenceIonosphere2000,RadioSci.,36(2),261–275,doi:10.1029/2000RS002432.Reinisch,B.W.,andI.A.Galkin,Globalionosphericradioobservatory(GIRO),Earth,Planets,andSpace,63,377-381,doi:10.5047/eps.2011.03.001,2011.

n.a. frissell , g. perry , e.s. miller m. moses , and a....

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