ADS-B Out Experiment

1. Introduction:
I was exploringsomewayto simulate ADS-BsignalandIworkmostlyon the Windows(Ihave Win10
installedin mylaptopalongwithUbuntuinVirtual Machine) platform. Ididsearchin the netand
came acrossa pythonscript ADSB_Encoder.py.
https://github.com/radiojitter/ADSB-Out
Setup
The proposedsetup isas follows:
The ADSB_Encoder.pyscriptdidnotrun(mypythonIDE is Anaconda) withanerrormessage.
Probablythe line
tmp1 = (encalt & 0xff8) << 1
has an issue.The variable encaltisbeingcalculatedasfloatandbitwise andoperationwasfailing
because one operance isfloat(encalt) andanotherone is aninteger(0xff8).
The line
encalt=(int(alt) +1000) / 25
was assigningfloatvalue toencalt
Thenthe line waschangedto
encalt=(int(alt) +1000) // 25
(base) D:aryahackADSB-Out-masterADSB-Out-master>pythonADSB_Encoder.py0xABCDEF
12.9716 77.5946 9999.0

2. The above command createsan IQ file of the ADS-Bsignal.The original file(Samples.iq8s) isof 4KB.
It mustbe 256 KB buffersize tobe usedinhackrf_transfer.exe.
The command dd isavailable inLinux andtouse in Windowswe needtoinstall Cygwin,andfrom
Cygwinprompt,the followingcommandisexecuted
$ ddif=Samples.iq8sof=Samples_256K.iq8sbs=4kseek=63
1+0 recordsin
1+0 recordsout
4096 bytes(4.1 kB, 4.0 KiB) copied,0.00365417 s, 1.1 MB/s
Nowthe updatedIQ file needstobe usedbyHackRF for transmission.Toachieve this,we use atool
calledhackrf_transfer.The Windowsversionof the tool couldbe found fromthe followinglinks.
https://www.radiojitter.com/gps-simulation-using-hackrf/
for hackrf_transfer.exe (windowsbinary) please refer
to https://github.com/mossmann/hackrf/issues/278
and http://downloads.myriadrf.org/builds/PothosSDR/?C=M;O=D
hackrf_transfer -t Samples_256K.iq8s -f 1090000000 -s 2000000 -x 10 -R

3. http://sonicgoose.com/using-dump1090-in-windows/
D:aryahackdump1090-win.1.09.0608.14>dump1090 --net
D:aryahackdump1090-win.1.09.0608.14>dump1090 --net-sbs-port30003
The above commandwouldsendthe ADS-Bdatato Base Stationreceivervia30003 port.
OpenVirtual radar---Tools----options.The emulatedreceiverwouldbe Base Stationandport
number30003 is allocatedtoit.
For webserver,port8085 is allocated. The radar view on the map couldbe seenbrowsingonthe
weblink
http://127.0.0.1/8085/VirtualRadar

5. Disclaimer:Transmission of1090 MHz signal in openarea is illegal.Thiskindof experimentshould
be done in a lab environmentwith limitedpoweror in a faraday cage. Please followthe law of the
land and be safe.
ADSB_Encoder.py Samples.iq8s Samples_256K.iq8s hackrf_transfer
HackRF
RTL-SDR Blog
V3/Nooelec SMART
Dump 1090Virtual Radar