Tagged: rtl2832

SigDigger: A Graphical Digital Signal Analyzer for Linux

Recently a new open source Linux based SDR application called SigDigger was released by programmer BatchDrake (Gonzalo J. Carracedo). It is based on his own DSP libraries called Sigutils and Suscan which can take advantage of multi-core CPUs. SigDigger also makes use of the SoapySDR interface, so it is compatible with almost all software defined radios including the RTL-SDR.

SigDigger Screenshot
SigDigger Screenshot

Like other general purpose SDR applications, SigDigger has your typical AM/FM/LSB/USB demodulation and audio playback features. However, it also has some key additional features that make it worth taking a look at if you're interested in reverse engineering, or taking a closer look at digital signals. The features include:

  • Both realtime and replay analysis modes
  • Analog audio playback (AM, FM, LSB and USB)
  • Baseband recording (full spectrum and per-channel)
  • Per-device gain presents
  • Dynamic spectrum browsing
  • ASK, FSK and PSK inspection
  • Gradient-descent SNR calculation
  • Different spectrum sources (cyclostarionary analysis, signal power…)
  • Symbol recording and visualization
  • Transition analysis

Planned features already implemented and just waiting to be exposed to the UI:

  • Parameter estimation (baudrate, constellation order…)
  • Fast symbol autocorrelation analysis
  • Automatic calculation of scrambling polynomials
  • Symbol stream codecs

Possible future features coming soon:

  • Symbol tagging (correspondence between symbols and groups of bits)
  • Automatic symbol tagging guessing
  • Automatic convolutional code detection
  • Viterbi decoding

We note that while the UI looks like GQRX, it is not based on GQRX at all. Rather BatchDrake just liked the minimal UI of GQRX. Also unlike GQRX, SigDigger is not based on GNU Radio, so it may be a bit more efficient and lightweight.

Below we've embedded a video that BatchDrake uploaded his YouTube channel which demonstrates SigDigger being used to inspect a PSK channel.

Using SigDigger to inspect a PSK channel

This software looks great, and we think it deserves some serious attention and testing, so check it out on the GitHub. Binary releases are also available, although BatchDrake notes that they are minimally tested, for x64 Linux only, and preferably for Debian-like distros. Alternatively, it can be installed from source, after installing the Sigutils and Suscan DSP library dependencies.

METEOR M Demodulator SDR# Plugin and LRPT-Decoder Updated

Thanks to Happysat for providing info on updates to these programs again. Meteor Demodulator V2.2 is a plugin for SDR# that connects to the M2 LRPT Decoder software. Together with an RTL-SDR and 137 MHz satellite antenna, these programs are used to receive, track, demodulate and decode Meteor M satellite signals into live weather satellite images. Happysat has a tutorial available here, however we note that at the time of this post it hasn't been updated to use the latest software versions.

The biggest change appears that you can now affect the decoder settings from within the SDR# plugin. This is useful because the METEOR M2-2 satellite appears to be changing it's operating mode often (number of infrared vs visible channels, data rate etc).

We also note news from Happysat that the Meteor M-N2-2 satellite has now changed frequency to 137.100 MHz mode 72K on 16 Aug. 9:30 Moscow time (6:30 UTC). Other users have also indicated that M2-2 is currently transmitting two IR channels, and one visible now. Meteor M2 appears to still be transmitting visible channels.

M2 LRPT Decoder V47:

- Added Meteor Demodulator V2.2 socket support

- only mode, sat, rgb are supported so far.

- Fix manual s-file processing

By design, the plug-in will manage the settings of the decoder and this should reduce the number of settings that must be done when changing the Meteor operating modes.

Example scheduler options:

M2_decoder_init_Line <rgb=123.jpg> or (rgb=125,444,555 ect)

In order for the decoder to work with Meteor Demodulator V2.2 http://happysat.nl/meteor_2.2.zip , the ini-file mode and sat entries must be assigned to auto!

M2_LRPT_Decoder.ini

mode=auto

sat=auto

http://happysat.nl/LRPT_Decoder_v47.zip

M2 LRPT Decoder V48:

- Remove debug window

http://happysat.nl/LRPT_Decoder_v48.zip

 

Meteor Demodulator V2.2

From TSSDR:

Added interaction with Meteor LRPT-Decoder via socket.

At the beginning of the data transmission, the configuration of the modulation speed and modulation type (satellite name) is transmitted to the decoder.

That is, there is no need to change the decoder settings when changing 72K / 80K and M2 / M2.2.

It will receive signal information from the plugin.

It is enough to change the speed in the scheduler.

A new scheduler command "M2_decoder_init_Line <>" has been added to the plugin.

Using it, you can transfer any commands that are in the ini file of the decoder (for example, the command to select channels to save a color picture:

M2_decoder_init_Line <rgb = 123.jpg>)

In general, this allows you to change the settings when changing the reception conditions only in the scheduler and not in the entire chain of programs for processing the signal from the satellite.

M2 decoder compatible with these functions is >V47

http://happysat.nl/meteor_2.2.zip

http://rtl-sdr.ru

Updated Meteor M2 Demodulator Plugin.
Updated Meteor M2 Demodulator Plugin.

WebWSPR: A Browser Based WSPR Decoder and Visualization Tool

A few days ago we posted about [dj0abr / Radio Electronics'] WebSDR software for QO-100. Having looked through his GitHub we've seen that he also has an a similar browser based server tool called WebWSPR for WSPR decoding and visualization (click with WebWSPR link) which was released earlier this year.

WSPR is an amateur radio digital HF mode designed to be decodable even if the signal is transmitted with very low power and is very weak. It can be used to help determine HF radio propagation conditions as WSPR reception reports are typically automatically uploaded to wsprnet. In the past we have been able to receive WSPR and similar modes like FT8 with our RTL-SDR V3 running in direct sampling mode.

Like his QO-100 WebSDR software, WebWSPR is designed to run on a single board computer like a Raspberry Pi or any Linux machine. It serves a web page that shows the WSPR waterfall, decoded data and has various WSPR related control options. The web page can be accessed remotely from any machine on the same network as the server, or could be put on the internet with port forwarding and a hostname service like noip.

A ready to use Raspberry Pi image for WebWSPR is available here (does not seem to support the latest Pi4 or 3B+ however). Manual installation instructions can be found here. The code is all open source and available on GitHub.

The software appears to take input from the soundcard for standard hardware receivers, but it should be possible to pipe audio from an RTL-SDR into pulseaudio, which the software can then use. The instructions from our RTL-SDR V3 WSJT-X tutorial may help.

WebWSPR Browser Screenshot
WebWSPR Browser Screenshot

Hackaday Article about the Slow Death of NOAA-15

If you've been following our blog, or have your own RTL-SDR based weather satellite station, then you'll know that the NOAA-15 APT satellite has been experiencing issues lately. There appear to be problems with it's camera scan motor resulting from it running low on lubrication. This is fully understandable as the satellite is 21 years old and well past it's expected life span. The satellite appears to be working some days, and producing garbage image other days.

Over on Hackaday, Dan Maloney has uploaded an interesting article that explores the history and technology behind NOAA-15's camera, and why it is now failing.

When NOAA-15 fails for good, don't feel too bad as we still have NOAA-18 and NOAA-19, the Russian Meteor M2, and Meteor M2-2 satellites, and the GOES satellites, all of which can be received by an RTL-SDR. Several new weather satellites are also planned for 2020 and onwards.

Talks from GNU Radio Days 2019

GNU Radio Days 2019 was a workshop held back in June. Within the last week recordings of the talks have been uploaded to YouTube by the Software Defined Radio Academy channel. The talks cover a wide range of cutting edge SDR research topics and projects. Many of the presenters have also made use of RTL-SDR dongles, as well as other higher end SDRs in their research.

All the talks are combined into two 3 hour long videos from the morning and day sessions from day one. Day two also has two videos that consist of recordings from the tutorial sessions which make use of the PlutoSDR. Finally there is also the keynote speech from Marcus Müller where he dives into the internal workings of GNU Radio.

Below we list the talks with timestamps for the YouTube video. Short text abstracts for each of the talks can also be found in the conference book. We note that not all the abstracts appear to have been presented in the videos, so it may be worth checking out the book for missed talks about passive radar, a 60 GHz link, embedded GNU Radio on a PlutoSDR, an SDR 802.11 infrared transmission system, PHY-MAC layer prototyping in dense IoT networks and hacking the DSMx Drone RC protocol.

Continue reading

Android ADS-B Flight Tracker with 3D Aircraft Display

ADSB Flight Tracker is an Android App that allows you to display ADS-B flight data in either 2D or 3D. It works either with data shared from others over the internet via aggregation sites like adsbexchange.com, or via your own home ADS-B receiver data coming from an RTL-SDR and dump1090 server on your home network. You can also directly connect to an RTL-SDR that is running on your phone and this will allow you to get data faster with less lag. Using data shared by others from the internet could have a delay of a few seconds.

In order to keep using the 3D and RTL-SDR features you'll need to unlock them for a small in-app purchase of $2 for each feature. Initially you get about 30 minutes trial time however.

2D and 3D Screenshots from ADS-B Flight Tracker
2D and 3D Screenshots from ADS-B Flight Tracker

Some interesting 3D videos were also recently posted to the apps Twitter page @ADSBFlightTrkr

SDRTrunk 0.4.0 Alpha 9 Updates Highlighted

You may recall that a few years ago we released a tutorial on how to set up and use [SDRTrunk]. Fast forward a few years and the software has seen numerous changes. This application was designed primarily for tracking trunking radio systems but also has the ability to decode things like MDC-1200, LoJack and more.

The software is compatible with many Software Defined Radios such as our RTL-SDR v3, HackRF and the Airspy. Some of the newer improvements include a bundled copy of java so that an installation of java is not required on the host computer, as well as decoding improvements for P25 among other digital voice modes. You can find a full list of improvements along with the latest release on [GitHub]

The biggest feature many have been waiting for is the ability to import talk groups for their radio system into the application from radio reference. While this has not yet been implemented, user [Twilliamson3] has created a [web application] that will convert table data from radio reference into a format that is supported by SDRTrunk.

SDRTrunk Screenshot
SDRTrunk Screenshot

SignalsEverywhere 10,000 Subscriber Interactive Live Stream with Giveaways on August 10 12PM EST

The SignalsEverywhere YouTube channel is quickly growing in size, and has recently passed the 10,000 subscriber milestone. If you weren't aware, Corrosive (aka KR0SIV aka Harold) who runs the channel has been consistently putting out high quality videos related to the software defined radio hobby. He's also started a podcast which also covers some interesting topics.

Some Recent SignalsEverywhere YouTube Videos
Some Recent SignalsEverywhere YouTube Videos

To celebrate hitting the 10,000 subscriber mark, Harold is planning an interactive 6 hour+ YouTube live stream which will begin on Saturday August 10 12PM EST time (11 hours from the time of this post)If you want to be automatically reminded of the stream, go to the live stream place holder, and click on set reminder.

The stream will be interactive as he is planning on setting up several SpyServer's that will be running across the HF, VHF, UHF and L-Bands. This will allow the audience to use SDR# to connect to his SDRs that are being used on the stream, allowing people to follow along with what Harold is doing on the stream, and ask questions about what they are seeing.

We're also helping to sponsor his stream and will be donating 5x RTL-SDR dongle + antenna kits, 5x RTL-SDR dongles, 1x Radarbox bundle, as well as one KerberosSDR to any giveaways that he plans on doing throughout the stream.

We really like Harolds work on YouTube, and if you are a fan of the content on our RTL-SDR.COM blog, then you really should be subscribed to his channel too.

Interactive SDR Live Stream | 10K Subscriber Celebration and Giveaway!