Paolo Romani (IZ1MLL) has recently released version 5.5 of his SDRSharp PDF Guide. The book is available for download on the Airspy downloads page, just scroll down to the title "SDR# Big Book" and choose your language. (At the time of this post only English and Italian are available for 5.5, but multiple languages are available for the older guides).
The latest version brings the book up to 214 pages in length, and adds information about the RTL-SDR Blog antenna kit, and new SDR# plugins like ListenInfo.
Thank you to Carl Reinemann (aka usradioguy) for submitting his article about Vitality GOES. Vitality GOES is an open source tool that displays the weather satellite images received by SatDump and/or goestools in a user friendly web interface that is accessible over a network connection.
SatDump and goestools are decoders that can be used to decode images from GOES and other satellites, when combined with a PC or single board computer, satellite antenna and RTL-SDR or similar SDR dongle. What they lack however is an easy way to display the received images, as the images are simply dumped to folders. If you're interested in getting started with GOES reception, we have a tutorial here.
Carl's article explains the purpose of Vitality GOES in detail and shows a few example screenshots. He notes how it can be used to display full disk images, composite together Meteor M2 images, present EMWIN data such as forecasts and warnings, and more.
Carl also notes that Vitality GOES was recently updated to V1.2 with the main update being added support for SatDump. SatDump can decode dozens of different weather satellites, not only GOES, so this opens up a wide range of possibilities.
Vitality GOES - Feature Overview
Vitality GOES: Example screenshots from Carl Reinemann (usaradioguy)
In one of his latest YouTube videos, Matt who runs the Tech Minds YouTube channels has posted a demonstration of the Radiosonde decoder plugin for SDR++ called sdrpp_radionsonde.
SDR++ is a software defined radio receiver program that is compatible with almost every SDR, including the RTL-SDR. Like other SDR programs, is has plugin capability, allowing third parties to develop additional features like decoders.
In the video Matt first shows how to install the plugin, demonstrates it being used with an example RS-41 radiosonde, and then shows how to use the log file outputs like the GPX track file on a free GPX map plotting website.
Radiosonde Decoder Plugin for SDR++
A radiosonde is a small sensor and radio package normally attached to a weather balloon. Meteorological agencies around the world typically launch two balloons a day from several locations to gather data for weather prediction. With an RTL-SDR, appropriate antenna and decoding software it is possible to decode the telemetry signal and gather the weather data yourself. You can also use the GPS data to chase and collect the fallen radiosonde package. We have an alternative tutorial on setting up a basic radiosonde decoder in Windows here.
Real time high quality speech to text is now possible with OpenAI's WhisperCPP, a high-performance and open source automatic speech recognition model.
In his latest video on YouTube, Aaron demonstrates how to use his latest DragonOS image to transcribe audio from a radio voice channel that is received with an RTL-SDR. He makes use of SDR4Space as the command line receiver, WhisperCPP as the AI transcriber and Mosquitto for monitoring WhisperCPP outputs and displaying the text to the terminal.
Here's a short video showing exactly how to setup and run SDR4space in such a way that real time IQ captures are demodulated and feed to WhisperCPP (High-performance inference of OpenAI's Whisper automatic speech recognition (ASR) model) for transcribing.
The latest DragonOS FocalX R28 comes w/ everything needed to do exactly what I show in this video, to include a sample tiny model.
You'll noticed in the video that jobs are placed in a queue for continued captures and results are also sent over to Mosquitto MQTT where a client can see messages as they are created.
I chose to use an RTLSDR v3 dongle for the capture, but it's possible to configure SDR4space to use a variety of soapy supported SDRs.
In his first video Aaron shows how to get setup with the system on DragonOS. Shortly after uploading his first tutorial, Aaron noticed that recompiling WhisperCPP on the local system yielded a significant decrease in the processing time of the AI. After recompiling locally the transcribing then became near real time. In the second video Aaron briefly demonstrates the real time transcription.
DragonOS FocalX Capture and Transcribe IQ w/ SDR4space/WhisperCPP/Mosquitto (RTLSDR, OpenAI)
DragonOS FocalX Captured IQ to Text Faster w/ SDR4space/WhisperCPP/Mosquitto (RTLSDR)
In the past we posted a similar project that was based on the Amazon Transcribe cloud service. However WhisperCPP runs on a local machine, is open source and seems to be at least as good as Amazon Transcribe. So this appears to be a significant leap in transcribing ability and we could see it being used to automatically create text logs and alerts based on various radio channels.
SDR++ is an open source receiver program compatible with most software defined radios including the RTL-SDR that has been going through rapid development making it now one of the top software choices. In runs on almost every platform, including Windows, Linux, MacOS and Android.
One feature that SDR++ has is it's remote server. This is similar to applications like rtl_tcp which allow an SDR on a remote device like a Raspberry Pi to be accessed over a network.
Over on YouTube, Matt from Tech Minds has uploaded a video showing how to run the SDR++ Server on MacOS, Windows and Raspberry Pi platforms.
Over on Hackaday we've seen an interesting post about the non-profit "Watch Duty" wildfire reporting smart phone app for Californians. Several populated regions of California are extremely prone to wildfires, and it's important that residents get timely notifications about nearby wildfires so they can evacuate early and/or prepare their defensible spaces.
Often by the time official notifications have gone out, it is too late. To solve this, the approach Watch Duty takes is to have volunteers monitoring public safety radio channels, and ADS-B aircraft positions in order to gather information in real time. Once critical information is established, the watch duty volunteer can push out a notification via the smart phone app.
The volunteers make use of receiver stations that consist of multiple RTL-SDR dongles with each dongle monitoring a different EMS radio system, and one additional RTL-SDR is used for ADS-B aircraft monitoring of helicopters and fire fighting aircraft. The stations appear to uplink radio data to the volunteers via a cellular modem or Starlink.
Earlier in the year Popular Science and Wired reported on Watch Duty as well, but did not mention the use of RTL-SDRs.
A Watch Duty monitoring station with multiple RTL-SDR Blog V3 dongles.
It also appears that the Twitter account for ADS-B Exchange @ADSBexhchange itself has been suspended too, as well as various other flight tracking Twitter bots that were using data from ADS-B Exchange. Elon Musk's tweet indicates that legal action is being taken against "Sweeney & organizations who supported harm to my family". It is unclear if this implies that legal action will be taken against ADS-B Exchange.
Elon Musk's Real-Time Doxxing Tweet
ADS-B (Automatic Dependent Surveillance–Broadcast) is a radio signal that is required to be broadcast by all aircraft for the purposes of air traffic control and collision avoidance. The ADS-B signal provides real time unencrypted location information that anyone with a low cost radio receiver like an RTL-SDR and cheap computer like a Raspberry Pi can receive, decode and turn into a live map of aircraft in the surrounding area.
ADS-B Exchange is an ADS-B aggregator that collects ADS-B data received from volunteers all over the world that are running RTL-SDR and other SDR dongles or radios operating as ADS-B receivers. Compared to more commercial flight tracking services like FlightAware and FlightRadar24 (who also make use of volunteer stations), ADS-B Exchange guarantees that they will not censor the tracking of military, police or private jets. This has generated debate in the past over whether this philosophy is either more moral or less moral.
ADS-B Exchange has been key to projects like "Dictator Alert" which tracks the real time location of the private jets of known dictators.
The Organized Crime and Corruption Reporting Project (OCCRP) has also made use of ADS-B Exchange data in the past to uncover the role that US civilian aircraft contractors are playing in the East African "kill chain".
Media have also used ADS-B Exchange to track the movements of the military aircraft like Black Hawk Helicopters and CBP Predator drones that were used to monitor crowds during the George Floyd protests.
Previously Elon Musk indicated that he would not ban the account following his private jet, however after the stalker altercation he appears to have rapidly changed his tune. Even without the Twitter bot, private jets can easily be tracked via ADS-B Exchange so any dedicated person could still gather this information without too much hassle. So it seems likely that legal action will be taken against ADS-B Exchange as per Elon's tweet. Other ADS-B data aggregators like FlightRadar24 and FlightAware should be safe from legal action as they do censor private aircraft upon request. Hopefully ADS-B exchange has prepared for this legal battle, which was probably an inevitable unfortunate outcome from their policy. If not from private jet owners, then the military or police would likely eventually take action if the data ever became a problem.
Over on YouTubem channel NotaRubicon Productions has uploaded a video describing how a KrakenSDR was used to find the location of a person jamming a repeater site. Amateur radio enthusiasts can utilize VHF or UHF repeater towers, which receive signals from lower power handheld or other radios, and retransmit that signal at high power on a slightly different frequency over a much wider area. Unfortunately malicious people can jam these repeaters by transmitting at the same time as other users, effectively denying use of the repeater by legitimate users.
If you weren't already aware, KrakenSDR is our 5-channel coherent radio based on RTL-SDRs, and it can be used for applications like radio direction finding. We successfully crowd funded the device on Crowd Supply, and the device is currently available for sale on Crowd Supply, Mouser and direct from our website krakenrf.com.
In this video I read the story of how we caught the jammer that had been jamming our GMRS repeater for months, and how by using the KrakenSDR Radio Direction Finder (RF locator), we were at his house in 1 hour.
The KrakenSDR can track a signal being transmitted from 100Mhz to 1Ghz - so I can track ham repeater jammers, GMRS repeater jammers, ham-radio transmitters, GMRS radios - pretty much any transmitter with a signal strong enough for you to receive.
How The KrakenSDR Located Our Repeater Jammer In 1 Hour. Overview of the KrakenRF Inc. RF Locator
