Tagged: rtl-sdr

DragonOS: LTE IMSI Sniffing using the LTE Sniffer Tool and an Ettus X310 SDR

DragonOS creator Aaron recently uploaded a video on YouTube showing how to capture IMSI data from an LTE-enabled phone by using the open-source LTE sniffer tool and Ettus X310 software-defined radio.

In the video, Aaron uses a simulated environment involving a Signal SDR Pro to simulate the LTE cell phone, a B205 Mini operating as the eNodeB (base station), and an Ettus X310 SDR for the actual LTE sniffing. The SRSRAN software running on DragonOS is used to simulate the LTE network environment.

Aaron goes on to show how the LTE sniffer software passively decodes the physical downlink control channels and captures IMSI numbers from user cell phones.

An IMSI is a unique identifier associated with a cell phone user's SIM card. IMSI sniffing cannot be used to listen to or decode voice, text, or data as they are all encrypted. However, bad actors can use IMSI sniffing to track the movement of devices/people.

DragonOS Noble Sniff + Passively Capture LTE IMSI (x310, b205mini, SignalSDR Pro)

Receiving Elektro-L3 LRIT Weather Satellite Images with an 11-Turn Helix Antenna and No Dish

Typically, a satellite dish is used to receive Elektro L3. As an example, our 70cm diameter Discovery Dish with linear feed can do this easily, and achieve an SNR of about 5-6 dB. However, as Meti shows, it is possible to receive this satellite even without a dish, and as he shows, an SNR of 1.5 dB is sufficient for decoding a perfect image.

Meti's antenna is an 11-turn RHCP helix made of copper wire, with a 17 x 17cm ground plane. In his post, he also notes a few interesting findings, noting that the height of the antenna off the ground is critical, rotating the helix can help, interference from cell towers can cause issues, and bending the corners of the ground plane can help.

In the rest of the post, Meti also shows how well the helix antenna works at receiving weather satellite signals from polar orbiting L-Band satellites like Meteor M2-3.

Meti's 11-Turn RHCP Helix Antenna
Meti's 11-Turn RHCP Helix Antenna

New Khanfar Software: Spot Scanner, Phased Based DF, IQ Playback

Recently, software developer M. Khanfar has been releasing a lot of new SDR and RTL-SDR compatible software including a Spectrum Analyzer and FM demodulator, directional antenna based radio direction finder, and a gr-phosphor based spectrum visualizer.

His pace of development continues, and recently he's developed three new programs.

The first is Khanfar Spot Scanner, a tool for detecting active signals. 

Khanfar Spot Scanner is a powerful and feature-rich spectrum analyzer designed for radio frequency enthusiasts, wireless security researchers, and professional RF engineers. Supporting multiple SDR hardware devices including RTL-SDR, Airspy, and HackRF, this software provides comprehensive spectrum visualization, automated signal detection, and in-depth analysis reporting.

Khanfar Spot Scanner

The second software is called "Khanfar Phase-Based Direction Finding" a tool for phase based radio direction finding.

Khanfar Phase-Based DF is advanced direction finding software that uses phase difference analysis to determine the bearing of radio signal sources. Unlike traditional direction finding systems that rely on directional antennas and signal strength comparison, this software utilizes an array of omnidirectional antennas and sophisticated signal processing algorithms to analyze the phase relationships between received signals.

We want to add to this a note that we're not entirely sure how this software can possibly work as phase based direction finding with RTL-SDRs requires synchronized clocks, and sample and phase alignment to be performed via a correlation with a noise source first which this software does not enable. Without those steps taken results will be totally random. We gave this software a brief test with a KrakenSDR, but as expected, did not see the results we expected. We're keen to hear feedback from other users.

Khanfar Phase-Based Direction Finding Software

The third program is called "Khanfar IQ Live-Rec-Playback" a tool for recording and playing back IQ files, with IQEngine integration.

Khanfar RTL-SDR IQ Live+Rec+Playback is a powerful, feature-rich spectrum analyzer application designed for RTL-SDR devices. This professional-grade software provides real-time RF spectrum visualization with GPU-accelerated rendering, comprehensive IQ data recording capabilities in multiple industry-standard formats, and advanced playback features for signal analysis. With IQEngine and IQ Analyzer integration, you can seamlessly export your recorded signals for comprehensive online analysis, visualization, and collaboration.

Khanfar IQ Live-Rec-Playback

GOES-19 Completes Transition to GOES-EAST Replacing GOES-16

NOAA GOES satellites are a popular way to receive beautiful full-disk weather images of the Earth using an RTL-SDR, antenna hardware such as the Discovery Dish, and software such as SatDump. The GOES-EAST satellite covers North and South America and was provided by GOES-16 until April 7th.

Over the past few months, NOAA has been moving the GOES-16 satellite into a storage orbit and the newer GOES-19 satellite, which was launched in June 2024, into the GOES-EAST position. Recently, on 7 April 2025, this transition was completed, and the GOES-16 was turned off, and the GOES-19 signal was activated.

For SatDump users, no configuration changes should be necessary to receive signals from GOES-19. However, Sanchez users will need to update their configuration file.

If you're interested, Carl Reinmann, owner of the usradioguy.com website, provides more detailed information about the transition and activation of GOES-19.

GOES-19 Received by Carl Reinmann
GOES-19 Received by Carl Reinmann

Using our RTL-SDR Blog Dipole as a V-Dipole for Receiving Weather Satellites

With our RTL-SDR Blog dipole antenna set, it is possible to use it in a "V-dipole" configuration to receive polar-orbiting weather satellites such as NOAA and Meteor at 137 MHz. More information on this can be found on our page at www.rtl-sdr.com/DIPOLE.

If you are after more visual instruction, "Baltic Lab" has uploaded a clear video on YouTube showing how to set the dipole leg lengths and angles correctly for weather satellite reception. 

We want to add that it is also important to remember to mount the antenna outdoors horizontally and in a north-south orientation with a clear view of the sky for the best results.

How To Build A V Dipole For Receiving Weather Satellites

IEEE Spectrum Article on Discovery Dish

Electrical engineering magazine IEEE Spectrum has recently posted an article about our Discovery Dish product, which was successfully crowd-funded on CrowdSupply and delivered to initial backers early this year. Discovery Dish is a 70-cm aluminum satellite dish with an active filtered feed. It is designed for receiving real-time weather data from GOES HRIT, GK-2A LRIT, FengYun LRIT, NOAA HRPT, Metop HRPT, Meteor M2 HRPT, and other weather satellites that operate around 1.69 GHz. There are also feeds for Inmarsat satellites, Hydroden Line observation, and S-band satellites.

In the article, Stephen Cass introduces the Discovery Dish, highlighting its practical uses and the convenience of disassembling it for easy packing in a suitcase during travel. He also shares his experience using the Discovery Dish to successfully receive images from the GOES-East satellite from the rooftop of his New York City apartment.

Finally, he mentions how he tested the hydrogen line feed as well, successfully seeing a hydrogen line peak when pointing at the galaxy.

Image from the IEEE Spectrum Article on Discovery Dish
Image from the IEEE Spectrum Article on Discovery Dish

Spectrum SDR: New Android App for RTL-SDR FM/AM Decoding and Spectrum Viewing

Thank you to James Mainwaring of Knowle Consultants for submitting news of the release of his latest Android app called "Spectrum SDR" for RTL-SDR. Knowle Consultants have previously released a range of RTL-SDR Android apps for FM, Airband, Ham FM and ADS-B reception. The new Spectrum SDR app has a spectrum viewer, as well as the ability to demodulate AM and FM signals.

James writes the following about Spectrum SDR:

This application is about having a bit of fun with those amazing little RTL-SDR dongles, whilst listening to AM/FM radio signals. It's nice and easy to use so why not give it a try?

- Covers the full frequency range of your RTL-SDR dongle
- AM and FM, wide and narrow
- FFT display
- Sample rates 240000 Hz to 2160000 Hz
- Bias tee control
- 75 presets over 5 pages
- Gain controls
- Squelch
- Built-in help

Spectrum SDR Android App Screenshot
Spectrum SDR Android App Screenshot

TechMinds: Testing out the SDRBerry Software on a Pi 4 with Touchscreen

Over on the TechMinds YouTube channel, Matt has posted a video demonstrating the SDRBerry software, which can be used with many SDR devices, including the RTL-SDR, on a Raspberry Pi with a touchscreen.

The SDRberry software is designed to be used on a touchscreen. As Matt points out, it has an aesthetically pleasing user interface and is compatible with almost any SDR software via the Soapy interface. Combining an SDR with a Pi 4 touchscreen and SDRberry results in an excellent hand-held SDR system.

In the video, Matt demonstrates the features of SDRberry, showing its RX features as well as some of its TX features, such as speech transmission and FT8, via a built-in WSjtx tab. He then shows the optional web interface, which is still in the early stages of development. Finally, he shows how to install the software and dependencies onto a fresh Raspbian image. 

SDRBERRY - This User Interface Is Just GORGEOUS! AND IT USES SOAPY TOO!