Over on YouTube Jon Kraft has been uploading videos explaining some interesting beamforming experiments he's been doing with his PlutoSDR. One experiment shows how to create a DIY monopulse tracker, which is a type of radio direction finding technique.
The PlutoSDR has two RX ports and two TX ports, and in this experiment he uses two directional antennas for the RX and one monopole antenna for the TX. Part 1 of this series explains standard phased array beam forming, and part 2 moves on to explain monopulse with adaptive tracking.
If you were interested in this, check out Jon's other videos on his channel. A recent video explains how time delays work in digital beamforming.
The project is described as a "hackable, open source, ESP32 amateur radio board with walkie-talkie functionality and data communication". We note that this is not a software defined radio, rather it's a highly customizable software controlled radio.
The advertising claims that you can communicate between SOCORAD32 devices by voice and text for up to 5km at 2W of power. No commercial or amateur radio license is required to use this radio since it operates in the 400 - 470 MHz license free bands that are available in many countries. Although we note that these bands in many countries may have power restrictions well below 2W, which would restrict range.
In recent updates they note that they have been refining the PCB and now added a battery holder and moved the push to talk button to a new position.
During crowd funding the device is selling for US$80 + $8 US shipping / $18 worldwide shipping.
SOCORAD32 can communicate between devices by voice or text for up to 5km, via license free bands.
Earlier in the month we posted about how rtl_433 has been ported to ESP32 devices that are combined with CC1101 or SC127X transceiver chips, such as the low cost LILYGO LoRa 32 boards available on Aliexpress.
Over on YouTube Matt from the Tech Minds channel has uploaded a video showing how to set up rtl_433 on an ESP32 device, and how to set it up with a home automation service like Home Assistant, Node Red or OpenHAB via an MQTT broker.
AirNav Systems are behind the RadarBox ADS-B tracking aggregator, one of several companies that use data obtained by volunteers running RTL-SDR dongles to collect ADS-B flight data from all over the world.
Recently they've launched a new project called ShipXplorer.com which is a marine AIS aggregation service. Like RadarBox, ShipXplorer relies on volunteers running receiver stations all around the world. AIS is an acronym for 'Automatic Identification System', and in a similar way to ADS-B on aircraft, AIS allows the real time tracking of marine vessel positions.
To help enthusiasts with AIS reception, AirNav have also launched an AIS optimized RTL-SDR dongle. At the moment we're not exactly sure how this dongle works, as it advertises NMEA output with no add-on programs required. So this may imply it has some onboard processing. But reviews imply that it is just an RTL-SDR dongle with TCXO. We are currently inquiring with AirNav Systems. UPDATE: We have clarified with AirNav and confirmed that the dongle is an RTL-SDR dongle with AIS modifications (LNA & TCXO). There is no onboard processing and the advertising text was an error.
AirNav Systems write:
Some great news on a new product we've been developing for the last year and that's just been released.
As you know our company has been in the industry for over 20 years, offering innovative and unique flight (RadarBox) tracking solutions. We supply multi-million USD companies with reliable/accurate worldwide real-time flight information and the RadarBox.com portal has now over 1.3 million accounts registered.
I'm reaching out to you to introduce you to AirNav System's ship tracker, ShipXplorer.com, which we launched a few months ago
About ShipXplorer.com:
ShipXplorer is a vessel tracking website that tracks global vessel movements in real time. ShipXplorer was developed to cater to the increasing navigational and tracking challenges faced by the maritime industry. In addition to offering professional maritime tracking solutions, the platform is also available for public use, with features and services specially developed for the burgeoning maritime enthusiast and vessel spotting community.
In addition to our recently launched ship tracking portal, we have a variety of AIS hardware, such as dongles and AIS antennas.
ShipXplorer AIS Dongle:
This high-performance dual channel AIS USB Receiver decodes AIS transmissions and enables the reception of AIS messages and data directly onto devices such as a Raspberry Pi or Laptop.
ShipXplorer AIS Optimized RTL-SDR Dongle
ShipXplorer AIS Antenna: ShipXplorer's omnidirectional AIS Antenna is optimized for long-range, dual channel (Channel A and B) 162 MHz VHF reception. It also ships with a 30 ft cable (SMA connector). Meant for outdoor use, this antenna is built with a fiberglass & aluminum alloy and can weather prolonged exposure to the elements.
ShipXplorer AIS Antenna
ShipXplorer Sea Range AIS Receiver:
SeaRange is ShipXplorer's newest 162 MHz, dual channel, AIS receiver. This brand-new model includes an added filter and an inbuilt amplifier designed to optimize AIS reception on both 162.025 MHz & 161.975 MHz frequencies.
And we are currently working on expanding our AIS coverage globally.
Researchers have discovered a way to transmit information wirelessly without power, simply by opening an closing a switch that connects a resistor to an antenna. This effect does not violate any physics - it works because the random thermal noise signature of the transmitter changes when the resistor is connected or disconnected.
The researchers used an RTL-SDR with high gain horn antenna and low noise amplifiers to measure changes in the thermal noise signature of the transmitter.
They also compare their idea to backscatter devices, which are another form of passive RF communications that make use of ambient radio signals such as from TV transmitters. They note that their thermal noise approach has a lower data rate and range compared to backscatter, but their next goal is to try and improve this.
Back in May 2016 we posted about Dejan Ornig, a then 26 year old student at the University of Maribor's Faculty of Criminal Justice, Slovenia who was almost imprisoned for using an RTL-SDR and finding a security flaw in Police TETRA communications. Dejan's story was one of the first of several stories we presented over the years involving a person getting into legal or political trouble from the use of SDRs like the RTL-SDR in more authoritarian countries.
TETRA is a RF digital voice and text communications protocol often used by authorities in European and other countries due to its ability to be secured via encryption. By using an RTL-SDR and an open source TETRA decoder, Dejan discovered that despite official documents specifying that all Police TETRA terminals must be authenticated (we assume this refers to encryption), none actually were.
Dejan went ahead and ethically reported his findings to the Slovenian authorities, working together with Police officers to disclose all his findings. However, in the end no action was taken, and Dejan took his findings to the press. It was then that Dejan was prosecuted by Slovenian Police, his house raided, and he discovered that Police had been collecting evidence against him for more than a year.
To complicate matters further it appears that Dejan also worked as an intelligence informant for the Police and was illegally instructed and helped by two Police detectives to hack into e-mails, Facebook profiles and other online communications of people deemed suspicious.
After seven years of court hearings, his case on the TETRA hack ended in 2022 with Dejan subjected to a seven month suspended prison sentence . Although suspension means that Dejan will not physically reside in jail, his record still records him as a criminal.
The criminal trial and conviction has led to Dejan having problems securing a job and moving forward with his life. He is currently asking for donations online in order to help get his life back on track. Dejan's full story can be read at the funding site. Alternatively you can donate via PayPal.
NOTE: As donation requests can often be scams, we have independently verified that it is indeed Dejan Ornig who submitted this story to us, and that the donation site and PayPal link is legitimate.
NOTE 2: In the past we have had issues moderating comments with stories involving transgender and female contributors. Dejan's story contains info about his sexual orientation and we will not accept derogatory comments on this site regarding this. If desired, please discuss the technical and legal nature of Dejan's situation, any other comments will be removed.
Back in August of 2021 we posted about the release of a Russian made portable software defined radio receiver called the "Arinst Dreamkit V1D". The Arinst SDR consists of a portable LCD screen and enclosure, with 16-bit ADC, 5 MHz of bandwidth and 1 - 3100 MHz tuning range. It was released for sale in September 2021 and was priced at only $230 + shipping.
It did have some drawbacks involving a lack of preselector filtering, and there being no digital decoding capabilities implemented in the software.
Fenu-radio is a popular tester of various software defined radios and has recently posted a review of the Arinst Dreamkit V2D. Initially he notes how in 2021 he first received his V1D model from Kazakhstan, and noted some problems with the lack of preselection, but other than that it worked well. His unit also had a display defect, however the manufacturer replaced the entire unit with the newer V2D model.
Fenu-radio notes that a battery is no longer included due to restrictions involving the transport of batteries through airmail, so he had to order a separate battery from Aliexpress. He importantly notes that the polarity of the battery is reversed from what the radio expects, so this has to be manually adjusted by changing the pins on the battery. If this is not done the battery or radio itself could be destroyed.
Other than that, Fenu-radio is impressed with the outer design of the V2D. He goes on to note how the V2D makes use of the R820T2 tuner, the same tuner used in standard RTL-SDR dongles. An up and downconverter is used to expand the range.
Fenu-radio then goes on to show the features of the radio, shows how it is operated, and provides a few audio examples of some stations received. He concludes positively:
The Arinst V2D is almost a "dream kit". It offers amazingly good reception on long, medium and shortwave without immediately clipping. And that on domestic active antennas. If you work with the manual gain control, you largely avoid intermodulation products and noise. The variety of functions is enormous and of high quality. At that point, you realize how hard Arinst has put in. The V2D can also convince above shortwave. What it particularly lacks here is a search function (scanner).
The case is sturdy and of good quality. But unfortunately there is criticism here. The housing shells were painted in places that shouldn't be painted! The painted flanks of the housing significantly worsen the shielding effect, which becomes noticeable with strong interference in reception if the V2D is operated with a telescopic antenna. The interference is particularly strong in the VHF range. Not only that. During the development of the V2D, far too little attention was paid to decoupling the display to prevent interference radiation in the reception branch. The approx. 4 hours Battery life was unfortunately never reached. After almost 3 hours of operation it was over.
Otherwise, the V2D is great fun. Especially with a remote antenna.
Arinst showed itself to be a very committed manufacturer when it came to correcting errors in the software and implementing suggestions.
At the time of this post the Arinst website and their sales platforms on Aliexpress and eBay does not appear to feature the 'Dreamkit V2D' product and we have no further info on the release date or pricing.
Today news has come out that ADS-B Exchange (ADSBx) founder Dan Streufert has sold ADSBx to a private firm called JETNET for (an estimated) $20 million. Dan was the sole owner of ADSBx, and after the sale he remains employed by JETNET. JETNET is a firm that provides aviation market intelligence to business customers.
UTICA, NY - JETNET, a leading provider of aviation data and market intelligence, announced today that it acquired ADS-B Exchange, one of the world’s largest networks of ADS-B/Mode S/MLAT feeders and providers of real-time and historical flight data. The acquisition is the second of what the company anticipates will be several future acquisitions as JETNET expands its data-driven product offerings for the aviation industry.
Founded in 2016 by Dan Streufert, ADS-B Exchange aggregates approximately 750,000 messages per second worldwide via receivers hosted by aviation enthusiasts around the world. The acquisition of ADS-B Exchange will enable JETNET to expand its flight data solutions with real-time information.
“ADS-B Exchange was founded as the go-to resource for aviation and flight-data enthusiasts,” said Dan Streufert, President and Founder of ADS-B Exchange. “Joining forces with JETNET is the perfect match as we look to meet the business needs of our users while maintaining our enthusiast roots and unfiltered data. With a long history of providing highly valuable data to the aviation industry, JETNET offers the resources we need to accelerate our growth.”
Like JETNET, ADS-B Exchange serves numerous constituents across the aviation industry, including Maintenance, Repair, Overhaul (MRO), airport operations, and aircraft leasing. In addition, its real-time data is used by dozens of commercial customers across numerous end markets, including aerospace & defense, government, research/academic, and financial services.
“We are committed to providing our customers with innovative product offerings which provide the information and intelligence they rely on to make critical business decisions,” said JETNET CEO Derek Swaim. “We’ve long admired ADS-B Exchange and know how strategic the company’s real-time data offerings are to the aviation industry. Dan has done an incredible job building a fast-growing business that customers love. We believe he, and the ADS-B Exchange platform, will bring significant value to our customers.”
About JETNET
As a leading provider of aviation market information, JETNET delivers comprehensive and reliable business aircraft research to its exclusive clientele of aviation professionals worldwide. JETNET is the ultimate source of information and intelligence on the worldwide business, commercial, and helicopter aircraft fleet and marketplace, comprising more than 110,000 airframes. Headquartered in its state-of-the-art facility in Utica, NY, JETNET offers comprehensive, user-friendly aircraft data via real-time internet access or regular updates. JETNET is a portfolio company of Silversmith Capital Partners.
ADSBExchange.com is an open source aggregator of ADS-B aircraft tracking data, contributed by volunteers who are all mostly running RTL-SDR radio dongles and Raspberry Pi based feeders. ADS-B data is transmitted at 1090 MHz and can be used to track aircraft movements.
Outrage over the sale has been expressed on Discord by various ADSBx open source co-developers who objected to the sale and appear to have received no compensation from the deal. The outrage has resulted in some co-developers actively encouraging that volunteer feeders remove their station from the ADSBx network. Several hundred of the over 9000 feeders have already disconnected their feeding stations, and the count is dropping (at the time of this post there were 9234 feeders).
Unlike similar ADS-B aggregators like FlightAware, FlightRadar24 and RadarBox, ADSBx is open source and promises to never censor the ADS-B data of billionaires, political leaders, military, police or other sensitive private aircraft. This has caused discussion over whether this free speech absolutist stance is either less or more moral. At the moment it is unclear if the acquisition will result in any ADSBx censorship policies changing.
Famously the @elonjet account (now @ElonJetNextDay) on Twitter used data from ADSBx. This account was used to automatically tweet out the location of Twitter owner Elon Musk's private jet in real time. The @elonjet account along with the @adsbexchange account was banned from Twitter shortly after Elon Musk's child had an altercation with a stalker. Legal action was threatened against @elonjet and "organizations who supported harm to [Elon Musk's] family" which could imply that ADSBx is in the legal action firing line.
While the sale may be discouraging to some, the project is still entirely open source, so it seems that only the branding and rights to the data collected have been sold. The following is entirely speculation on our behalf, but given that ADSBx was likely not very profitable and struggling to cover operating costs from donations only, and the threat of substantial legal action being taken against it's sole owner, the sale seems like the smart decision for the founder. We hope that the co-developers will receive some fair compensation as well.
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.
