ADS-B decoding allows you to receive GPS and other information from aircraft in your vicinity. We also have a tutorial about ADS-B decoding available here.
The BeagleBone Black is a small embedded Linux computer, similar to the Raspberry Pi. It has enough computational power to run the RTL-SDR and ADS-B decoder.
The Outernet project aims to be a “library in the sky” satellite based service that will provide free access to daily downloads of data such as books, news, videos and other information. It’s goal is to provide people who may not have easy physical or uncensored access to the internet an easy way to access daily information.
Outernet Overview Poster
To achieve this goal the Outernet project needs a good low cost satellite receiver. The RTL-SDR is a good candidate, but it’s performance at about 1.5 GHz isn’t great, and this appears to be the frequency Outernet wants to use. To improve the performance for satellite reception at these frequencies they have redesigned the RTL-SDR by replacing the R820T2 tuner with a MAX2120 tuner chip which tunes from 925 MHz to 2175 MHz. They have also improved the components used and the PCB layout. The regular RTL2832U chip is used as the ADC and USB interface, so the maximum bandwidth and ADC bit depth remain the same.
The Lantern is currently being prototyped and there is a discussion about it on Reddit. They are aiming for a price point below $20, but note that it will take time to get to that low price as mass production will be required.
Balint Seeber is a researcher at Ettus, designers of the USRP line of software defined radios. Every so often he gives an interesting conference talk about his latest projects. This time he’s given a talk at Ruxmon Sydney in April of this year and it has just been uploaded to YouTube.
In the talk Balint overviews the projects that he’s working on or completed. His topics include:
His work with creating his own battery powered GSM base station including a live demo where members from the audience connect to and call him via the base station.
His work with FPV drones and creating an SDR based FPV digital video system.
Hacking restaurant pagers.
Attempting to communicate with and revive the ISEE-3 spacecraft using the large radio dish at Arecibo.
Gathering actual RADAR data from listening to a real airport active RADAR system and plotting the returns on a map.
Investigating RFID tags and attempting to unlock his car via an SDR.
Ruxmon Sydney (April 2015): Hacking the Wireless World with SDR
We’ve received a note from RTL-SDR.com reader Tim about a new ExtIO module available for the HackRF and HDSDR. ExtIO stands for External IO, and is a special DLL file that allows HDSDR and other software to access hardware like the HackRF.
To use it, simply copy the HackRF ExtIO dll file into the HDSDR directory, and select it when opening HDSDR. The module currently supports 2, 4, 8, 10, 12.5, 16 and 20 MSPS sample rates. We tested it briefly on our own HackRF and it ran just fine at all sample rates.
Over on YouTube user Cameron Conover has uploaded a video where he tests the effectiveness of the optional HackRF RF shield and also shows how to install it. The shield solders on to the RF front end of the HackRF and is intended to block signals from entering the device other than through the antenna.
To test the effectiveness of the shield Cameron uses a signal generator to transmit a test signal at 406 MHz. He shows that without the shield in place the HackRF with a 50 Ohm terminator on the antenna input strongly picks up the test signal. After soldering in the shield and testing again, the test signal can no longer be picked up.
RTL-SDR.com reader Marty Wittrock has written in to let us know that he has been successful in getting his HF modified “KN0CK” RTL-SDRs (and by extension standard RTL-SDRs) to work with Zadig and HDSDR on a PC running the Windows 10 technical preview on a VMWare image.
We decided to also test RTL-SDR compatibility with other common software on our own Windows 10 system. We tested SDR#, SDR-Radio, CubicSDR and Unitrunker and found them all to work fine with no problems either. Finally, we also tested the Airpsy and SDRPlay on Windows 10 and found no problems with those devices either.
After reading an article by the Washington Post about FBI surveillance aircraft spotted in the air after the West Balimore riots, John Wiseman decided to look for more information about these aircraft. Fortunately, John had on his hands a database of about 2 months of ADS-B data that was collected by his continuously running RTL-SDR + BeagleBone Black ADS-B decoder set up.
From reports on the internet John found out that FBI aircraft squawked with 4414 or 4415 codes, and used call signs like JENNA or JENA. With this information John decided to take a look through his ADS-B logs to see if if he could find anything similar. Out of 15,000 aircraft he had tracked, he found 9 aircraft in his logs that matched the criteria, and saw that they did exhibit suspicious behaviour such as circling over LA for hours at a time. Then by looking up their FAA records of the tail numbers of the suspicious aircraft, he was able to discover that these aircraft where licensed to companies with names like NG Research, OBR Leasing, Aerographics Inc. and PXW Services which are suspected Department of Justice front companies. John also writes:
If you Google the tail numbers of aircraft registered to those companies, you start to find forum and mailing list posts (often at sites that tilt toward paranoid/conspiracy/right wing, but not always) with people discussing these specific tail numbers and linking them to the FBI. Some of the supposed evidence includes details of radio communications that people have heard, e.g. talking about “being on station” or using callsigns that start with JENNA, JENA or ROSS, which are supposedly used by the FBI. Other posts claim that DOJ/FBI surveillance aircraft often squawk 4414 or 4415 on their transponders.
The planes use “persistent wide-area surveillance” to photograph large areas for hours at a time, Stanley said. The captured images allow authorities to go back in time, if necessary, to trace pedestrians and vehicles who come to their attention.
Other devices known as “dirtboxes,” “Stingrays” or “IMSI catchers” can capture cellphone data. Stanley said it’s still unclear what technologies have been used in the surveillance flights.
Possible FBI Surviellance Aircraft Path from flightradar24.com
Back in 2013 we posted about Juha Vierinen’s project in which he created a passive radar system from two RTL-SDR dongles, two Yagi antennas, and some custom processing code. Passive radar can be used to detect flying aircraft by listening for signals bouncing off their fuselage and can also be used to detect meteors entering the atmosphere. The radar is passive because it does not use a transmitter, but instead relies on other already strong transmitters such as FM broadcast radio stations. Juha writes:
A passive radar is a special type of radar [that] doesn’t require you to have a transmitter. You rely on a radio transmitter of opportunity provided by somebody else to illuminate radar targets. This can be your local radio or television station broadcasting with up to several megawatts of power.
How passive radar works
His previous write up was brief, but now over on Hackaday Juha has made a detailed post about his RTL-SDR passive radar project. In the post he explains what passive radar is, shows some examples of his and others results, shows how it can be done with an RTL-SDR dongle, and finally briefly explains the signal processing required. In his next post Juha aims to go into further detail on how passive radar works in practice.
Below we show a video that shows an example of one of his passive radar tests that was performed with a USRP software defined radio and two Yagi antennas.
This video shows a lot of airplanes around the New England area detected using a simple passive radar setup, consisting of: one USRP and two yagi antennas, a quad core linux PC. Every now and then an occasional specular meteor echo is observed too.
