Collabora've*monitoring** of*Air*Traffic*and*RF*spectrum:** - - PowerPoint PPT Presentation

Collabora've*monitoring**

• f*Air*Traffic*and*RF*spectrum:**

the**OpenSky*and*ElectroSense*projects*

* Talk*at*ICTP*–IAEA*Workshop*on*Environmental*Mapping:* Mobilising*Trust*in*Measurements*and*Engaging*Scien'fic**Ci'zenry* Trieste,*10.*March*2017**

Fabio*Ricciato*(speaker),*on*behalf*of** Vincent*Lenders,*MaThias*Schaefer,*Domenico*Gius'niano,*Roberto*Calvo* *…*and*many*others*

About*myself*

• Fabio*Ricciato*
• Present*

– Associate*Professor*Faculty*of*Computer*and*Informa'on*Science,*University*

• f*Ljubljana,*Slovenia*

– Living*in*Trieste*

• Past*

– Worked**at*Forschungszentrum*Telekomunica'on*Wien*(FTW),*Austria* – Worked*at*Univ.*of*Salento,*Italy* – Worked*at*Austrian*Ins'tute*of*Technology*(AIT),*Austria* – Studied*in*Roma,*Univ.*La*Sapienza*(MS’99,*PhD’03)** *

• Competence*Field:*Communica)on*Networks**

– Wired*&*Wireless,*local]*&*wide]area,*…* – Different*topics,*technologies,*layers** – System]oriented,*applica'on]oriented,*experimental**

*

About*this*talk*

• Presen'ng*Two*crowdsourced*networks*

*

• Ini'ated*and*funded*by*armasuisse**

About*Armasuisse*

• Armasuisse*is*a*federal'agency'of'the'Swiss'Confedera4on.*It*is*

the* procurement* organiza)on* for* armaments* of* Switzerland* and*is*affiliated*with*the*Federal*Department*of*Defence,*Civil' Protec4on' and* Sport.* It* employs* around* 750* people.* It* is* responsible* for* research,* development,* evalua)on,* procurement,* maintenance* and* liquida)on* of* materials* and* construc)on*of*the*Swiss*Army.**

• i.e.,*the*Swiss*DARPA*…*
• website:*hTp://www.ar.admin.ch*
• reference*person:*Dr.*Vincent*Lenders*

Common*aspects*

• Rela'vely*“young”*projects*

– OpenSky**500+*sensors* – Electrosense,*30+*sensors* – …*but*growing**

• Open*data,*open*source*code*

– all*data*provided*freely*for*research*purposes* – historic*data,*online*feeds*

Common*aspects*

• Data]intensive*24/7*monitoring*

– 10s*kB/sec/sensor*** – 10s]100s*GB/day*

*

• Centralized*archiving*and*processing*

– server(s)*and*storage*hosted*&*maintained*by* armasuisse*

1*kB/sec/sensor**x*24*hours*=*0.86*GB/day/sensor***

Common*challenges*

• Huge*volume*of*data*in*the*back]end**

– data*streaming*technologies* – heavy*on*hardware,*solware*maintenance,*data*care**

• Support*for*hosts/contributors*

– Ini'al*sensor*shipment,*assistance*with*ini'al*setup,* troubleshoo'ng**

• Other*specific*technical*challenges*discussed*

later*…*

*

Electrosense*

Thanks*to*MaThias*Schaefer*and*Vincent*Lenders*

Background:*Primary*Surveillance* Radar%

reflected*radio*signal*

Secondary*Surveillance*Radar*(SSR)*

interroga)on* message* reply*message* (in*response*to* interroga)on)* * broadcast*messages* (e.g.,*posi)on*reports)*

1030%MHz% 1090%MHz%

Transponder*

Secondary*Surveillance*Radar*(SSR)*

reply*message* (in*response*to* interroga)on)* * broadcast*messages* (e.g.,*posi)on*reports)* ModeNS* Receiver*

1090%MHz%

Secondary*Surveillance*Radar*(SSR)*

Internet% ModeNS* Receiver*

1090%MHz%

SSR,*Mode]S*and*ADS]B*

SSR*messages* Mode]S* ADS]B*

Mode]A* Mode]C* contain*GPS*posi)ons*

Mode]S*receivers*

RTL]SDR* ≈25*EUR* Rasberri*Pi* ≈*35*EUR* Radarcape*+*JetVision** ≈*700]800*EUR*

…%

Mode]S*receivers*

Radarcape*+*JetVision** ≈*700]800*EUR* ≈*150]200*EUR*

Installa'on*in*Ljubljana*

flightradar24.com*

Crowdsourced,*but*not*open*

• pensky]network.org*

• pensky]network.org*

example*of*recep'on*range*at*high*al'tude*

example*of*recep'on*range*at*high*al'tude*

example*of*recep'on*range*at*high*al'tude*

example*of*indoor*deployment*

OpenSky*Data*Inges'on*Layer*

Back]end*Architecture*

• pensky*data**
• Data*are*open*

– ADS]B*data*accessible*via*online*API** – historical*accessible*via*online*query* – more*detailed*raw*(meta)data*available*on* request*

• Code*is*open*

– hTps://github.com/openskynetwork*

What*for?**

• Ongoing*research*work*w/*opensky*data*

– SSR*security*(e.g.,*spoofing*&*an']spoofing,* verifica'on,*fingerprin'ng)** – Spa'o/temporal*analysis*of*Air*Traffic** – Mul']latera'on,*posi'oning*algorithms* – Privacy]preserving*monitoring* – Es'ma'on*of*meteorological*parameters*(!)* – …*

Ongoing*work*by*Dr.*Vincent*Lenders*

Retrieving*Meteorological* Informa'on*From*OpenSky*Data*

• Informa'on*about*upper*air*

meteorological*condi'ons*is* important*for*

– Avia'on*safety* – Weather*forcas'ng*

• However,*only*sparse*sensing*

capabili'es*today*

– Weather%balloon:*only*sporadic* launches*at*few*sites*due*to*high* cost* – Windprofiler%/%Lidar:*limited* availability*and*range*(max.*8*km)* – Airplanes:*only*dedicated*aircral* are*equipped*(~600*aircral*in* Europe*[9])*

3 4*

Mo'va'on*

• ATC*data*in*SSR*Mode*S*and*ADS]B*traffic*can*been*

used*to*derive*meteorological*parameters*[1]* * *

35*

Alterna've*Approach*

! Temperature:*[4],*[5]* ! Wind:*[4],*[5]** ! Pressure* ! Turbulence:*[2]* [1]*Rui*Pinheiro,*Opensky*Workshop*2015**

• Can*we*use*OpenSky*data*to*infer*

– Temperature*?* – Wind*speed*?* – Wind*direc'on*?** – Pressure*?* – Turbulence*?*

• What*is*the*expected*accuracy*?*
• What*is*the*expected*coverage*?*
• How*many*aircral*send*the*required*informa'on*?*

*

36*

Open*Ques'ons*

Technical*Challenges*w/*OpenSky*data*

– ADS]B*doesn’t*provide*enough* informa'on*to*derive*useful* meteorological*parameters* – Mode*S*interroga'ons*are*directed* – Mode*S*replies*do*not*include* message*type* – Data*type*of*Mode*S*replies*must* be*inferred*based*on*format*and* context* – Decoding*of*Mode*S*replies* without*the*knowledge*of*the* corresponding*interroga'ons*

38*

Es'ma'on*of*Meteorological* Parameters*

39*

Es'ma'on*of*Temperature*&*Pressure*

Temperature%

Constant* True*airspeed* Mach*number*

c vt M

References: [7], [8] References: [4], [5]

Pressure%

International Standard Atmosphere (ISA)

Pressure*at*zero* al'tude* 101325*Pa* Temperature*at*zero* al'tude* 288.15*K* Accelera'on*due*to* gravity* 9.80665*m/s2* Lapse*rate* ]6.5{10]3*K/m* Gas*constant*for*air* 287.053*J/(kg*K)*

40*

Es'ma'on*of*Wind*Speed*&*Direc'on*

Wind%

Wind%Speed% Wind%DirecJon%

~ vw = ~ vg − ~ vt

k~ vwk ~ vw =  vg sin ↵g − vt sin ↵t vg cos ↵g − vt cos ↵t

• True*airspeed*

Heading* Ground*speed* Track*angle*

vt vg αt αg

References: [4], [5]

∠(~ vw)

~ vg ~ vt ~ vw

41*

Ongoing*Work*

• Compare*to*reference*data**

– Weather*balloon*data*from*MeteoSwiss* – Numerical*weather*model*from*MeteoSwiss*

• Match*reference*data*to*es'mated*data*points**

→*colloca'ons*

– No*perfect*matches:*'me*difference*and*loca'on*distance*

• Evaluated*components*

– Comm]B*Decoder* – Preprocessing*filters* – Message*availability*world]wide*(3*con'nents)* – Es'ma'on*of*meteorological*parameters*

Thanks*to*Roberto*Calvo*and*Domenico*Gius'niano*

Background:*the*radio*spectrum*

• EM*waves*

Background:*the*radio*spectrum*

• EM*spectrum*

Background:*the*radio*spectrum*

• Radio*communica'ons*

Spectrum*Alloca'on*

Unlicensed*ISM*bands*(Europe)*

434%MHz% 868%MHz% 2.4%GHz% 5.4%GHz%

Mo'va'ons**

• The*Electromagne'c*(EM)*spectrum*is*heavily*used*
• Frequency*assignment*is*well*structured*and*

defined.**

• But*the*actual*usage*in*space/'me*is*unknown**
• Today’s*spectrum*measurements*are*mainly*

performed*by*a*few*governmental*agencies*with* expensive*specialized*hardware.**

– limited*space/'me*sampling*density*

Mo'va'ons**

• Goal*of*Electrosense:*crowdsourcing*spectrum*

monitoring*using%commodity%low'cost'hardware*

• Democra'ze*knowledge*of*radio*spectrum*usage*
• Complements*other*monitoring*ini'a'ves*

Microsol*Spectrum* Observatory* DARPA*spectrum** collabora'on*challenge** Google*Spectrum*Database*

Distributed*monitoring,** Centralized*Archiving*

Applica'ons*

Electrosense*sensors*evolu'on*

…*

Single]board*computer*(RPi)*+* RF*front]end*(RTL]SDR*USB)*for*signal*acquisi'on* RPi]2,*new*version*of*RTL]SDR* *+*GPS*device*for*'ming*synchroniza'on* Frequency]range* extension* 2]3.6*GHz** and*5]6*GHz*

Commodity*Low]cost*Hardware** is*evolving*

Monitoring*single*band*

Fmin*=*20*MHz* Frequency* Time* Acquisi'on** Bandwidth*2.2*MHz** Fmax=1.8/3.6*GHz**

Sweeping*the*frequency*range*

Frequency* Time* Fmin*=*20*MHz* Fmax=1.8*GHz** Acquisi'on** Bandwidth*2.2*MHz**

Local*Processing*at*sensor*

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                      

   

100 200 300 400 −2 2 Sampling, Segmentation, DC Removal Sample Number Amplitude 100 200 300 400 −2 2 Windowing Sample Number Amplitude −1.2−0.6 0.6 1.2 −100 −50 FFT, Envelope Detection Frequency [MHz] Power [dB] −1.2−0.6 0.6 1.2 −100 −50 Averaging Frequency [MHz] Power[dB]

Back]end*Architecture*

Electrosense*API*

• hTps://electrosense.org/open]api]spec.html*
• The*API*allows*to*retrieve*spectrum*data*from*any*sensor.*
• Raw*or*Aggregated*mode.*
• Different*'me*and*frequency*resolu'ons*to*visualize*the*

spectrum.**

switch]off*of*analog*TV*channel*to* make*space*for*DVB]T*

500 1000 1500

10/16/2015

8/1/2015 5/1/2015 2/1/2015 12/1/2014

Frequency (MHz)

• 80
• 7
• 6
• 5
• 4

Power (dBm)

Specific*Challenges*in*wideband* spectrum*monitoring*

• Lack*of*calibra'on*

– device*heteregeneity,*manufacturing*tolerances* – rela've*rather*than*absolute*power* measurements**

• Impact*of*antenna*model*

– frequency*selec'vity*profile*

Impact*of*antenna*

discone*antenna**

Future*Evolu'on*

• Collabora've*decoding*

hTp://eprints.networks.imdea.org/1524/1/paper_camera_ready_4628451*

Data*Funnel*

I/Q*samples* raw*data% What*informa'on*is*of*interest*?**

Average*power*in*each*band* Which*modula'on*format*?* Posi'on*of*transmiTer* What*is*being*transmiTed*?** Fingerp'ng*of*TransmiTer*

InformaJon%%

• f*interest*

Data*Funnel*

How*to*split*between*local*and* centralized*processing*?**

Data*Funnel*

How*to*split*between*local*and* centralized*processing*?**

Non]profit*Electrosense*associa'on* (“Verein”)**

• Objec've:*seeking*a*more*efficient,*safe*and*reliable*use*of*

the*electromagne'c*space*by*improving*the*accessibility*of* spectrum*data*for*the*general*public**

• Following*the*crowdsourcing*model,*people*will*contribute*by*

sharing*their*data*to*the*Associa'on*and*on*the*other*hand* receive*data*back**

• Benefit*of*having*a*independent*non]profit*organiza'on*

taking*care*of*the*coordina'on*with*the*crowd**

• Thanks*for*your*aTen'on*
• Ques'ons*?*
• Help*us*to*improve*coverage:*adopt*a*sensor*!**

– hTps://opensky]network.org/join* – hTps://electrosense.org/join.html*

• For*follow]up*

– domenico.gius'niano@imdea.org*(Electrosense)* – vincent.lenders@armasuisse.org*(OpenSky)* – fabio.ricciato@fri.uni]lj.si*(posi'oning,*privacy] preserving*mul'latera'on)*