JAERO Updated: Now supports 10.5k Aero-H and Aero-H+

The JAERO decoder for AERO signals on Inmarsat satellites has recently been updated to version 1.03. This new version supports the decoding of 10.5k Aero-H and Aero-H+ signals. The author of JAERO Jonti writes that on these channels he’s seeing significantly more traffic than on the narrowband signals and that he was suprised to see that other non-aircraft messages such news was broadcast on this 10.5k signal. Jonti writes about his experience in developing the 10.5k decoder and his experience with receiving the messages in this post.

AERO is a system similar to VHF ACARS, but instead of running over terrestrial VHF it uses an L-band Inmarsat satellite link. Our first post about the JAERO decoder explains a bit about AERO, and this previous tutorial about decoding Inmarsat EGC messages may help you get set up with decoding Inmarsat signals in general.

Jonti discovered that news updates are also broadcast on 10.5k AERO.
Jonti discovered that news updates are also broadcast on 10.5k AERO.
What the 10.5k signals look like compared to the 600 signals.
What the 10.5k signals look like compared to the 600 signals.

If you like Jonti’s apps, then please remember to donate a small amount to him so that he can continue to work on them more. His PayPal donate button can be at the bottom of his main page.

Building a NEST Thermostat with Arduino and an RTL-SDR

The Nest thermostat is a smart thermostat that learns your schedule and automatically adjusts the heat in your house for optimal energy savings.  Tristan didn’t want to buy a Nest, but wanted to replicate the Nest thermostat’s functionality by using an Arduino to automatically regulate his apartments central heating boiler. To do this he needed to find a way to turn the heating on and off programatically.

Fortunately Tristan’s current thermostat is wireless, so he decided to use his RTL-SDR to sniff the data it sends to try and find the on and off signals. By using SDR# he was able to discover the radio traffic stream in the ISM band at 433 MHz. After simply recording the signal audio, he passed the audio file into Audacity to analyze the messages. He discovered that the ON and OFF signals were on-off key (OOK) modulated, and he was able to discover the binary control string and pulse timings.

With this information at hand, Tristan was then able to use a cheap 433 MHz radio transmitter together with his Arduino to replicate the ON/OFF boiler control signals. In the future Tristan plans to add a temperature sensor and web interface to monitor everything.

In the past we’ve also posted about a similar project by Tom Taylor where he reverse engineers his thermostat with an RTL-SDR and controls it with an Arduino.

thermostat_bits

PiTX QRP TX Shield for WSPR on 20M Now For Sale

Back in October 2015 we posted about a piece of software for the Raspberry Pi called PiTX. PiTX allows you to turn your Raspberry Pi into a fully functional RF transmitter. When combined with an RTL-SDR a full transceiver radio can be built using the QTCSDR software.

PiTX works by modulating the GPIO pins on the Pi in such a way that it is able to produce FM modulation. The major problem with using this method of producing radio is that it creates large amounts of harmonics and interference outside of the intended transmit frequency. Interference like this is illegal and could potentially disrupt life critical radio systems such as emergency services, cellphones and air traffic control.

In order to cleanly transmit with PiTX an output RF filter should be used. Recently, the team over at TAPR.org have released a 20M WSPR TX filter shield. WSPR is pronounced “Whisper” and is short for “Weak Signal Propagation Reporter Network“. It is a type of amateur radio signal that can be broadcast and received around the world by using very low transmit power. Radio amateurs use it to see how far their signal can travel when using very low power (QRP) and to investigate signal propagation conditions. 

The 20M WSPR shield sells for $20 at www.tapr.org/kits_20M-wspr-pi.html.

The WSPR shield sitting on top of a Raspberry Pi.
The WSPR shield sitting on top of a Raspberry Pi.

Combining the bandwidth of multiple RTL-SDRs: Now working in GQRX!

A few days ago we posted how Oliver, an RTL-SDR experimenter, managed to (incoherently) combine the bandwidths of two RTL-SDR dongles to create a 4.4 MHz FFT display in GNU Radio. Now Oliver has taken this idea further and produced an updated version of his GNU Radio program

Oliver’s GNU Radio program is now capable of combining four RTL-SDR dongles and is now also capable of piping the output via a FIFO to GQRX. With four RTL-SDR dongles you can get a total bandwidth of 8.4 MHz. He also writes that it is even possible to listen to analog signals that are in overlapping areas.

Four RTL-SDRs producing a total of 8.4 MHz of bandwidth in GQRX.
Four RTL-SDRs producing a total of 8.4 MHz of bandwidth in GQRX.

More talks from Defcon 23

Some more SDR and RF related talks from Defcon 23. See our previous posts [1][2] for other talks that we posted previously.

Colby Moore – Spread Spectrum Satcom Hacking

Recently there have been several highly publicized talks about satellite hacking. However, most only touch on the theoretical rather than demonstrate actual vulnerabilities and real world attack scenarios. This talk will demystify some of the technologies behind satellite communications and do what no one has done before – take the audience step-by-step from reverse engineering to exploitation of the GlobalStar simplex satcom protocol and demonstrate a full blown signals intelligence collection and spoofing capability. I will also demonstrate how an attacker might simulate critical conditions in satellite connected SCADA systems.

In recent years, Globalstar has gained popularity with the introduction of its consumer focused SPOT asset-tracking solutions. During the session, I’ll deconstruct the transmitters used in these (and commercial) solutions and reveal design and implementation flaws that result in the ability to intercept, spoof, falsify, and intelligently jam communications. Due to design tradeoffs these vulnerabilities are realistically unpatchable and put millions of devices, critical infrastructure, emergency services, and high value assets at risk.

DEF CON 23 - Colby Moore - Spread Spectrum Satcom Hacking

DaKahuna and satanklawz – Introduction to SDR and the Wireless Village

In many circumstances, we all have to wear different hats when pursuing hobbies, jobs and research. This session will discuss the exploration and use of software defined radio from two perspectives; that of a security researcher and Ham Radio operator. We will cover common uses and abuses of hardware to make them work like transceivers that the Ham crowed is use too, as well as extending the same hardware for other research applications. Additionally we will highlight some of the application of this knowledge for use at The Wireless Village! Come and join this interactive session; audience participation is encouraged.

DEF CON 23 - DaKahuna and satanklawz - Introduction to SDR and the Wireless Village

Lin Huang and Qing Yang – Low cost GPS simulator: GPS spoofing by SDR

It is known that GPS L1 signal is unencrypted so that someone can produce or replay the fake GPS signal to make GPS receivers get wrong positioning results. There are many companies provide commercial GPS emulators, which can be used for the GPS spoofing, but the commercial emulators are quite expensive, or at least not free. Now we found by integrating some open source projects related to GPS we can produce GPS signal through SDR tools, e.g. USRP / bladeRF. This makes the attack cost very low. It may influence all the civilian use GPS chipset. In this presentation, the basic GPS system principle, signal structure, mathematical models of pseudo-range and Doppler effect will be introduced. The useful open source projects on Internet will be shared with attendees.

DEF CON 23 - Lin Huang and Qing Yang - Low cost GPS simulator: GPS spoofing by SDR

Investigating QRM from Powerline Ethernet Devices with a Funcube Dongle

Over on his blog Andrew has posted a good writeup where he determines the QRM (interference) effects of a PLT (power line transmission) device. PLTs are also known as ethernet/internet over powerline devices and they are devices that plug into an electricity socket and use household electricity wires to create a computer network, thus eliminating the need for ethernet cables or WiFi. However, many hams and radio hobbyists hate these devices because they believe that they can cause significant amount of radio interference, especially on HF.

In his investigation Andrew bought a pair of Netgear Powerline 500 PLTs. He then plugged the PLTs in and started streaming a movie over the powerline network connection to cause maximum radiation. Then using his Funcube dongle and SDR# he investigated ham bands to see if these devices brought any noise.

In his results Andrew writes that he barely saw any interference caused by these devices. Some interference was noticed at 17 meters and 12 meters, but he notes that the amateur portion was left relatively unaffected. Many hams believe these devices can completely wipe out HF, but it seems that this is untrue, at least for this particular PLT model.

Netgear PLT devices
Netgear PLT devices

Demonstrating the ARM Radio

Back in November 2015 we posted about the ARM Radio, a minimalist direct sampling software defined radio that runs almost entirely on an ARM processor on a STM32F429 discovery board. It can tune from about 8 kHz up to 900 kHz, which covers the VLF, LF and some of the MF bands. 

Now over on YouTube amateur radio hobbyist W9RAN has uploaded a video where he demonstrates an ARM Radio that he built. He shows the radio in operation with it clearly receiving some NDB’s and some AM broadcast stations.

ARM Radio demo BY W9RAN

Hamradioscience.com’s Review of the SDRplay

The author of hamradioscience.com has posted a review of his thoughts on the SDRplay RSP software defined radio. The SDRplay is a SDR that is a $150 USD software defined radio that can be considered as a next stage level up from the RTL-SDR dongle. We consider it somewhat of a competitor to the Airspy SDR ($199 USD).

The review goes over the marketed specs, what you get in the box, software, support and its real world performance. The review is positive and the author concludes:

At the $150 price point there just isn’t much to complain about. The SDRPlay represents an excellent value in a low cost wideband SDR receiver. If you are currently considering getting involved with SDR radio, or want to trade up from the RTL dongle world, then the SDR Play should definitely be on your short list.

If you are interested in mid level SDR’s like the SDRplay then keep an eye out for our own review on RTL-SDR.com coming out in the next few weeks. We will be doing an in depth review and comparison of the Airspy, SDRplay and HackRF.

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