The New Pace of Gliding...

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2 The New Pace f Gliding... r the past tw years, a grup f technically skilled glider pilts have started t use traffic awareness data messages, sent by "anti-cllisin" devices, as received by grund statins. nitially it was all abut safety in and arund traffic areas f airprts whilst allwing fr autmated lgbk keeping. Their success encuraged a grup f the develpers t take their prgram t an even higher level by relaying the decrypted psitin data ver the nternet. My club in Varese, taly, uses a regular Flarm unit cnnected t a PC, in rder t keep track f all aircraft mvements, as required by the lcal law. This is ne f the reasns why Flarm is cmpulsry equipment at ur club. By the way, the club's website shws a map f the airprt traffic area where anyne can see all detected aircraft (and yu can even listen t the radi chat, live). Nice, r harsh, if yu're sitting at wrk r in bed with flu, depending n yur md! Fr F 4 me it's a jy t see that there's gliding activity even in less grgeus days. This dcument allwed the develpment f hardware devices which prved t be cmpatible with the Swiss trafficawareness system. THE ENCRYPTON The Flarm data transmissin prtcl is encrypted, but in 2008 it was cracked by a mysterius hacker wh published a cmprehensive dcument (a link in the Flarm Wikipedia leads t the text) and signed it with the serial numbers f his wn wristwatch and f a GPS, s if smeday he reveals himself, we can be sure it's really him. By the way, let me declare my admiratin fr the simple cncept and the effectiveness f the Flarm device. have n dubt that it has greatly helped reduce the number f in-flight cllisins between gliders and against grund bstacles in the Alps (wires, antennas). ":U::.. : :Aircraft::.. CN: BL Ansbach Neumarkl Ch Regist: D KMBL c Flarm d: 3E7BC5 Rth Regensburg Type: Tw Plane Treuchthnqen Owner: FLG Blaubeuren Straub Airfield: EDMC nglstadt 00 Mdel: HK36 Super Dimna Freq.: Landshul Last time: 18:59:01 Latitude: Lngitude: NLirnberg Am~erg

3 in Germany, the sky is grey and fggy, but n glidernet.rg can see a Super Dimna spiralling up the Engelberg muntain at metres in Switzerland. ts signal is being received by a grund statin in nterlaken, sme 50 kmaway. At the same time, a Twin Astir is lazily maintaining altitude in Sctland in a weak nekntter". As clickn the aircraft's wn icn, a small windw pens with all the details the wner has indicated and authrised when setting the preferences f his Flarm device. They range frm a maximum f indeterminatin, t specific details such as registratin marks, make and mdel, even the name f the pilt. Lacking basic inf, the website assigns a casual set f characters. Mre and mre aircraft have a Flarm nbard in Eurpe, especially in Germany with the whle Alpine territry, including helicpters and f Cllisins are rare, but the human implicatins are always dramatic t say the least, as they invlve respnsibilities twards ther individuals, and their families as well. While 'm deeply grateful fr this additin t the safety f gliding, wuld have firmly preferred an pen" system as was the riginal declaratin by the Swiss develpment grup back in But mre n this later. f BEST RANGE Off-the-shelf hardware can be used t set up a receiver C i! live.glidernet.rg (.48012;' 'On]1 statin, thanks t the decryptin dcument and using a gd antenna, a USBbradcast televisin receiver, a small prcessing mdule like a Raspberry Pi r similar (Banana Pi, Cubiebard 2, Odrid U3, r simply a partitin n a PC). n the best cnditins, a receptin range f Flarm devices is 100 km which has been achieved. mpressive! The data can then be sent t a server n the nternet, which makes it visible fr anyne as it is superimpsed ver a wrld map. As 'm writing, 'm in a huse :: _ 8 \ h.t H.pperled t." : ~~Pertecip. L', Mnd ~ Vd.fC'lne CntrlL.). Offri 0 trve n pus,., " D AltrtPrefentl 15m X i2~m lit' i"om X 11~tn"" 99-m'( X 79S111'" 6m X 136m+ ~8~m X 39-:-m... Abve: What yu see in a generic map, while the menu shws the list f all received aircraft. (Yucan arrange thse by name, altitude, cntest number etc.). 5

4 airplanes n file. SOFTWARE AND DATA Yu can easily find the Open Glider Netwrk grup f develpers. Sme f them are als wrking n a small cmpatible transmitter as a side prject, with the aim f prducing an pen-surce "tracking system" fr gliders. They explicitly declare that they are nt willing t prvide an alternative anti-cllisin device. A lt f pprtunities may be traced, especially if they haven't taken any care abut what can be bradcast. Fr example, it tk me less than a minute t identify the mtrglider ver the Engelberg as a Super Dimna, and t find in Ggle the fficial base airprt and the name f the wner. S, if yu care abut privacy, select "n" t the "send Flarm D menu" and registratin in yur device settings. magine if yu made up an excuse with yur bss t g gliding n a beautiful day, and he catches yu having fun in the '>":,"' f.".>':"... / e : ~".~.' r.... "/' :::.. r: pub/sub... ~'... r, nternet.--_fj<j>".t!!su:...~_~... ~.~'':..:~:~., eub/sub. Schematic f the present system pening, thugh wuldn't g as far as t say that the ATC services might make use f Flarm receiving statins, nt even unfficially, as they lack any chance t enter a fully certified wrking envirn-ment. BG BROTHER All this spreading f infrmatin cmes with an impact. Anyne can bserve Flarm traffics (r ADS-b traffics n similar websites) where sme grund statins have been cnnected t the nternet. Flarmnet already ffers a database f devices, s the pilts shuld be aware that they can be 6 Alps at 3,000 metres. Alleged airspace incursins might als be detected, but a lawyer wuld demnstrate (at a cst!) that a nn-certified data surce can't be prf enugh fr a guilty sentence. Nevertheless, please respect airspace rules, as frm them cmes the future f ur sprt. Already t many lbbies are wrking t segregate VFR flights in restricted areas. LET'S BULD Yu may want t make yur wn experiments, r fllw the available set f instructins published by the Open Glider Netwrk. A list f current registered grund statins is available with technical details and pictures, at: http: / / wiki. glidernet.rg / list-f-receivers First, yu have t get a Raspberry Pi (B) cmputer fr abut $US3S.t's small and features an ARM prcessr, Ethernet netwrk prt, up t 512 MB f RAM and a few USB prts, including a 4GB SD card as mass and system strage. The OS is a simple variant f Linux. Fr the initial setup, a hme cmputer will use a classic Terminal emulatr, same as yu wuld d fr ld ruters and ther vintage devices. All the sftware yu need is ready t be.. cpied as an image n receivers: the SD card. tier Secnd, yu must select a DVB-t receiver based n the RTL2832Uchipset, which allws the sftware t set the crrect listening infr. frequencies. f the Raspberry has an nternet cnnectin thrugh Ethernet r the ptinal WiFi, all decrypted data will be sent t ne f the APRS servers and they will appear n the map page. Third, the antenna. The small standard DVB-t antenna will be gd fr the first grund tests, but will have a limited range. There are tw better alternatives: a Grund-plane antenna (a very cmmn type fr amateur radi) with a preamplifier, and the Cllinear antenna design. The latter lks like a lng plastic tube, inside f which are a series f skilfully cut and sldered pieces f caxial cable f precise dimensins. f yu have an interest abut this antenna, please have a lk at the ARRL Antenna Bk, page 248 (nline at: / TgXW ). Flarm units, when perated in Eurpe, use the 868 MHz band, which is licence-free fr small

5 New pen tracking device as tested in Pland pwer devices like remte cntrls and intruder alarms. TV accessries wrk at very similar frequencies, s there's plenty t chse frm in terms f amplifiers and receivers. A gd cllinear antenna perfectly matched fr Flarm applicatin in the 868 band can be rdered frm a Chinese wrkshp thrugh Alibaba: Furth, cmes installatin. The ideal lcatin has a cmplete view f the sky in the desired directin, withut tall cncrete buildings and trees at least a dzen meters away. Tp f a hill, if yu can prvide pwer, cnnectin and service wuld be best. During a lightning strm, the antenna shuld be discnnected frm the receiver, r at least this shuld be unplugged frm the pwer surce. Dn't make a grund" cnnectin, r the antenna will wrk very well as a lighting rd. f March 2015 as the lder v5 will stp wrking. This has happened in the past, as prgrammed and clearly stated by the factry "in the interest f implementing the best pssible effectiveness". There are differences, thugh. This time, the press-releases intrduce a new wrldwide tracking system based n Flarm's servers, which is described as allwing t preserve the full rights t the pilts' privacy. The server will allw the develpment f a Flarm prprietary tracking system fr clubs and cm- petitins, while permitting als easy access t data fr Search and Rescue peratins. t's easy t understand that, in rder t allw all this, the transmitted data will be encrypted with a new cde. The small Atmel prcessr installed in Flarm devices can't supprt the very high calculatin prperties necessary fr a very strng encryptin, but nevertheless sme experts have identified sme tricks which, if adpted by Flarm, might make an independent decryptin very time cnsuming, in the regin f many weeks r mnths f hard wrk. This is t say that all this nice Glidemet traffic service may shrtly fall int the cntrl f the Flarm factry. Whether the firm will be able t immediately prvide a similar service, r we may have t wait sme time, dn't have a clue. The OGN tracking system might as well cntinue n its riginal path, separating frm the Flarm legacy. Whatever, we'll see. Prgress is gd and nbdy can stp it. A/d Cernezzi 1/ CONCLUSON Flarm has annunced the 6th versin f the firmware fr their devices. Update is mandatry by the end A Raspberry cmputer in a weather-prf bx with a pwer supply ver-the-ethernet. 7