Category: Airband

RTLSDR4Everyone: Review of the FlightAware ADS-B RTL-SDR

Akos from the RTLSDR4Everyone blog has recently uploaded a review of the FlightAware ADS-B ProStick RTL-SDR dongle. The FlightAware (FA) dongle is a standard RTL-SDR with SMA connector, but with a very low noise figure LNA built into the front end. This low noise figure helps improve the SNR of ADS-B signals, resulting in more decodes and further range. We previously reviewed the FlightAware dongle in our own review available here.

In his post Akos reviews the FA dongle on its use as a general RTL-SDR as well as an ADS-B receiver. His review is initially critical to some of the misinformed advertising claims made by FA. He then goes on to show some noise floor scans and some ADS-B reception comparisons. Finally he shows some modifications that can be made to improve the cooling of the PCB.

He concludes that the FA ProStick works very well on improving ADS-B performance, but that overloading due to the increased gain is common.


ADS-B Traffic Analytics with Valo and an RTL-SDR

Valo is a software service for real time big data streaming analytics of data from many sensors.  On their website they explain their service as follows.

Valo is a single platform for streaming (real time) and batch (historical) data analysis. Valo provides multi-paradigm big data storage for both semi-structured and numerical data. Valo contains a powerful analytics engine for processing all of this data. Finally Valo is super simple – a single tool that can be up and running in minutes.

Recently Rémi Selva wrote in to let us know about an interesting use-case for Valo which involves the RTL-SDR. In his post Rémi shows us how he uses an RTL-SDR, Raspberry Pi running dump1090, and Valo to create interesting data visualizations of the ADS-B aircraft data. He not only shows how to visualize the data in Valo, but also how to use queries to dig deeper into the data, looking for patterns.

Valo ADS-B Data Flow
Valo ADS-B Data Flow

Rémi writes that what he’s done is simply a proof of concept that shows the power of Valo. He writes that one such interesting future development could be using Valo to detect FBI/CIA surveillance aircraft. Previously we posted about how an RTL-SDR user discovered these surveillance aircraft by their odd circular flight paths. The analytics engine of Valo could be used to automatically detect odd flight patterns such as from these surveillance aircraft. 

Plotting the history of aircraft coming into land at HK airport
Plotting the history of aircraft coming into land at HK airport

Building an ESP8266 Based Plane Spotter with an RTL-SDR Feeder

Living near Zurich airport, Daniel Eichorn wanted an easy way to show his house guests what planes are flying near him. Usually he opens up his Flightradar24 app on his phone, but he wanted a more permanent always on display. To do this Daniel has built an ESP8266 based OLED display which automatically displays the ADS-B flight information of aircraft outside his window. The ESP8266 is a very cheap and highly popular WiFi module which can give a microcontroller access to WiFi networks.

Daniel feeds his locally received ADS-B data to using a Raspberry Pi and RTL-SDR. While actually feeding ADS-B data with an RTL-SDR is not required to make the ESP8266 module work, this step ensures that he has good local coverage of his area. The ESP8266 module then queries the database via WiFi for information about planes in his area and displays the information on the OLED screen.

In previous posts we also showed how the ESP8266 could be used to transmit data like NTSC TV in a similar way to Rpitx.

ESP8266 + OLED screen displaying ADS-B data.
ESP8266 + OLED screen displaying ADS-B data.

An ADS-B Decoder for the GOMX-3 Satellite ADS-B Repeater

The GOMX-3 is a CubeSat which carries an experimental ADS-B repeater. Since it is a satellite the experimental receiver hopes to be able to receive ADS-B from orbit, then beam it back down to earth at a frequency of about 437 MHz using a GFSK at 19200 baud high data rate transmission protocol. From space the GOM3-X satellite can see many aircraft at one time and space based tracking allows for aircraft tracking over oceans.

Recently the creators of the satellite, GomSpace released a complete decoder for the ADS-B downlink, and now it has also been turned into a GNU Radio flowgraph by Daniel Estevez which can output decoded aircraft position data directly to a KML file which can then be opened in Google Earth or similar. This blog by DK3WN shows several logged decodes of the satellite and shows what the signal looks like in SDR#. Some of his posts also curiously shows what looks to be a Windows decoder, or logger, though we were unable to find a download for it.

Decoding the downlink should give you real time ADS-B data in your area, but the full log of stored stored data is apparently only downloaded when the satellite passes over the GomSpace groundstations which are mostly located in the EU.

[Also mentioned on Hackaday]
The GOMX-3 ADS-B Downlink Signal.
The GOMX-3 ADS-B Downlink Signal.
Aircraft detected by the GOM3-X Satellite ADS-B Receiver.
Logged aircraft detected by the GOM3-X Satellite ADS-B Receiver. Major flight corridors are visible.

SDRplay Updates: Android Support, ADS-B Decoder Upgrades and Acquisition of Studio1 Software

The SDRplay team have been hard at work during the last few weeks. First they announced beta support for Android via SDRtouch, then they announced an improved ADS-B decoder, and finally they have just announced their acquisition of Studio1. 

The SDRplay is a 12-bit software defined radio with tuning range between 100kHz – 2 GHz. Many consider it along with the Airspy to be the next stage up from an RTL-SDR dongle. 

Android Support

The author of SDRTouch on Android recently announced support for the SDRplay. SDRTouch is a Android program similar in operation to PC based software like SDR#. To access the beta you can sign up at this link. Currently there is support for up to 2 MHz of bandwidth.

Improved ADS-B Decoder

Back in March the SDRplay team released ADS-B decoder software for their SDR with the promise of improving its performance in the near future. 

Recently the SDRplay team released an updated version of their ADS-B decoder for the Raspberry Pi which now fully utilizes the full 12-bits of the ADC and takes advantage of the full 8 MHz bandwidth. Jon, the head of marketing at SDRplay writes the following:

We now have an updated beta version of ADS-B for both the Raspberry Pi 2 and 3. This is based upon the 16bit Mutability version of dump1090 developed by Oliver Jowett and unlocks the full 12 bit performance of the RSP1. People should see a significant performance improvement over the dump1090_sdrplus version, which was based upon 8 bit code. The latest beta version can be downloaded in binary form from . Should anyone have questions or feedback, please contact [email protected]

We plan to eventually compare the SDRplay with the Airspy and RTL-SDR on ADS-B performance. If you are interested we previously did a review of the SDRplay, Airspy and HackRF here, but as the SDRplay did not have ADS-B back then, that particular test was not done.

Acquisition of Studio1 SDR Software

The last major piece of news is that SDRplay have now acquired the Studio1 SDR software. Studio1 is a paid SDR program, similar in nature to SDR#/HDSDR/SDR-Console. Like HDSDR, Studio1 is a spinoff from the old WinRad software. Their press release reads:

SDRplay Limited has today announced that it has reached an agreement with Sandro Sfregola, (formerly CEO of SDR Applications S.a.s.) to acquire all Rights, Title and Interest in Studio 1 a leading software package for Software Defined Radio applications.

Jon Hudson, SDRplay Marketing Director said: “We are delighted to have reached this agreement with Sandro to acquire Studio 1. Studio 1 is the perfect complement to our SDR hardware products and gives us the ideal platform to deliver a complete class leading SDR solution for our customers. We look forward to working with Sandro and further developing Studio 1 to unlock the full capability of our current and future products”.

Hudson added: “Studio1 has established a strong customer base with users of many other SDR hardware products. Studio 1 will continue to be available as a stand-alone product from WoodBoxRadio for the foreseeable future , but we also look forward to further developing Studio 1 to specifically benefit present and future owners of our products”

Sandro Sfregola added: “I am very pleased to have reached this agreement with SDRplay. The long term future for SDR lies in complete end to end solutions and I feel the SDRplay RSP combined with Studio 1 software gives users an outstanding combination of performance and affordability”.

About Studio 1:

Studio1 was developed in Italy by SDR Applications S.a.s. and has hundreds of happy customers around the world.Studio 1 is known for its user friendly stylish GUI, CPU efficiency and advanced DSP capabilities, including features notavailable on other SDR software packages.

About SDRplay:

SDRplay limited is a UK company and consists of a small group of engineers with strong connections to the UK Wireless semiconductor industry. SDRplay announced its first product, the RSP1 in August 2014

We believe that this is a good move for SDRplay, as one of the major issues with the RSP SDR was the lack of decently supported software.



A new RTL-SDR based Portable ADS-B Kit for Pilots is on Kickstarter

Back in March we posted about the FlightBox, a portable RTL-SDR ADS-B 1090ES and 978UAT receiver built for use by pilots in small aircraft. 1090ES provides ADS-B which allows a pilot to see on a map where other aircraft are, and 978UAT provides other services such as weather radar. The FlightBox is essentially a Raspberry Pi 2 combined with two RTL-SDR dongles, two antennas, a GPS receiver and is preloaded with the stratux software. The two channel FlightBox receiver currently sells for $250 USD.

Recently a new similar ADS-B product for pilots made by a different company has been released on Kickstarter. The new product is made by a company called RF-Connect and is similar to the FlightBox, but is powered by an Odroid C1. RF-Connect are also the programmers behind the ADS-B on Android app which was one of the first apps to be able to receive FIS-B weather data and display it on a map. 

The product receives 978UAT and 1090ES ADS-B signals using two RTL-SDR dongles, and then transmits the data via WiFi to an Android or iOS tablet running flight navigation software.

The Kickstarter early backer price is $150 USD for a single channel 978UAT only capable receiver or $200 USD for the dual channel 1090ES and 978UAT receiver. This contrasts with the FlightBox price of $200 and $250 USD for similar products, however the standard backer price for the RF-Connect ADS-B receiver is the same as the FlightBox.

The RF-Connect ADS-B Receiver transmitting data to a tablet.
The RF-Connect ADS-B Receiver transmitting data to a tablet.
The parts inside the ADS-B Receiver. Two RTL-SDR dongles, GPS receiver, two antennas, WiFi dongle, Odroid.
The parts inside the ADS-B Receiver. Two RTL-SDR dongles, GPS receiver, two antennas, WiFi dongle, Odroid.

RF-Connect have also uploaded a video showing their ADS-B on Android app in action.

RTLSDR4Everyone: ADS-B Bias-T Filter and External amplification

Akos from the RTLSDR4Everyone blog has recently come out with a new post where he explains how to get the best ADS-B reception with an LNA and filter. In his experiments he uses an LNA4ALL low noise amplifier and and ADS-B Filter, both of which are sold by Adam 9A4QV. New versions of the filter sold by Adam now also include a built in bias-tee circuit which allows you to easily power the LNA4ALL over the coax cable, allowing you to place it externally.

In the post Akos shows where to optimally place the LNA and how you can use your Raspberry Pi together with the ADS-B filter with bias-T in order to power an antenna mounted LNA4ALL. The post also discusses what the cheapest solution is for European customers attempting to optimize their ADS-B reception.

ADS-B Setup including a filter, bias tee, LNA and Raspberry Pi.
ADS-B Setup including a filter, bias tee, LNA and Raspberry Pi.

Review: FlightAware ADS-B RTL-SDR + LNA Positioning

Recently FlightAware released a new RTL-SDR dongle sold at zero profit at $16.95 USD. It’s main feature is that it comes with an ADS-B optimized low noise amplifier (LNA) built directly into the dongle. is a flight tracking service that aims to track aircraft via many volunteer ADS-B contributors around the world who use low cost receivers such as the RTL-SDR. In this post we will review their new dongle and hopefully at the same time provide some basic insights to LNA positioning theory to show in what situations this dongle will work well.

FlightAware Dongle Outside
FlightAware Dongle Outside

A good LNA has a low noise figure and a high IIP3 value. Here is what these things mean.

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