Tagged: Automatic dependent surveillance broadcast

FlightAware Release their Pro Stick Plus: An ADS-B Optimized RTL-SDR with LNA and 1090 MHz Filter Built in

Back in March of this year we posted about the release of the FlightAware "Pro Stick". The Pro Stick is FlightAware's ADS-B optimized RTL-SDR dongle. It uses a low noise figure LNA on the RF front end to reduce the system noise figure, thus improving the SNR at 1090 MHz. Because the added gain of the LNA can easily cause overload problems if there are other strong signals around, FlightAware recommend using one of their 1090 MHz ADS-B filters in front of the dongle to prevent overload.

FlightAware have just come out with the "Pro Stick Plus" which is the same as their Pro Stick, but now with the 1090 MHz filter built into the dongle itself. The Pro Stick Plus costs $20.95 USD on Amazon, which is a good deal cheaper than buying the standard Pro Stick ($16.95 USD) plus their ADS-B filter ($19.95 USD), which totals $36.90. Customers outside of the USA can purchase the Pro Stick Plus from seller "WiFi Expert" on eBay for $29.95 USD.

FlightAware.com is a company that specializes in live air travel tracking. Most of their data comes from volunteers running RTL-SDR ADS-B receivers.

The new Pro Stick Plus RTL-SDR based ADS-B Receiver from FlightAware.
The new Pro Stick Plus RTL-SDR based ADS-B Receiver from FlightAware.

Over on their forums and on Amazon, they announced the device and specs. They wrote:

FlightAware is excited to announce the next evolution of USB SDR sticks for ADS-B reception! The new Pro Stick Plus USB SDR builds on the popular Pro Stick by adding a built-in 1090 MHz bandpass filter. The built-in filter allows for increased performance and range of reception by 10-20% for installations where filtering is beneficial. Areas with moderate RF noise, as is typically experienced in most urban areas, generally benefit from filtering. By integrating the filter into the SDR stick, we are able to reduce the total cost by more than 40% when compared to buying a Pro Stick and an external filter.

Specifications:

  • Filter: 1,075 MHz to 1,105 MHz pass band with insertion loss of 2.3 dB; 30 dB attenuation on other frequencies
  • Amp: 19 dB Integrated Amplifier which can increase your ADS-B range 20-100% more compared to dongles from other vendors which can increase range 10-20% over a Pro Stick in environments where filtering is beneficial
  • Native SMA connector
  • Supported by PiAware
  • R820T2 RTL2832U chips
  • USB powered, 5V @ 300mA

Note that this dongle is only for ADS-B at 1090 MHz, and not for 978 MHz UAT signals, as the filter will cut that frequency out.

Back in April, we did a review of the original Pro Stick. We found its performance on ADS-B reception to be excellent, but only when a filter was used. The low NF LNA theoretically improves the SNR of ADS-B signals by about 7-8 dB, but in reality there is too much gain causing signal overload everywhere, thus making reception impossible without the filter. Rural environments may not need a filter, but in a typical urban or city environment strong FM/TV/GSM/etc signals are abundant and these signals easily overloaded the Pro Stick when no filtering was used. This new Pro Stick Plus dongle completely solves that problem at a low cost with its built in filter.

Remember that if you are using a run of coax cable between the LNA and RTL-SDR, then it is more optimal to use an external LNA, like the LNA4ALL. Only an external LNA mounted near the antenna can help overcome coax, connector, filter and other losses as well as reducing the system noise figure. The FlightAware dongles are the optimal solution when they are mounted as close to the antenna as possible. This is usually the case when running the FlightAware feeder software on a Raspberry Pi.

We hope to soon review the Pro Stick Plus, however we assume it will operate nearly identically to the Pro Stick + FlightAware ADS-B filter combination.

New Posts From RTLSDR4Everyone: Avoiding RTL-SDR Ripoffs, ADS-B Antenna Reviews, Travel Kits and Direct Sampling vs Upconverter vs SDRPlay

Akos from the rtlsdr4everyone blog has been busy uploading new posts over the past few days. His first post is part three in a series that discusses how to avoid ripoffs when buying RTL-SDR dongles. The RTL-SDR market has recently become quite saturated, and it is now easy to purchase something that most experienced users would consider a ripoff. His post shows some examples of what he considers to be poor value choices available on eBay.

An example of a ripoff price.
An example of a ripoff price.

His second post discusses his methodology for testing dongles on their ADS-B performance. The second post then leads into the third post in which he compares four antennas on ADS-B reception. He compares two telescopic whip antennas, one set to 1/2 wave length, and the other set to 1/4 wave, a NooElec 5dBi whip antenna, and the FlightAware ADS-B antenna. His results show that the FlightAware antenna was the best performer, followed by the 1/2 wave telescopic whip, then the NooElec 5dBi whip and finally the 1/4 wave telescopic whip. The fourth post continues the ADS-B topic, and he reviews the NooElec 5dBi ADS-B antenna. Although the performance is not as good as the FlightAware antenna he mentions that it is much smaller and great for portable use. If  you are interested, we have also a review of the FlightAware antenna, and we also found its performance to be excellent.

The four ADS-B antennas tested in Akos' review.
The four ADS-B antennas tested in Akos’ review.

In his fifth post Akos shows what his RTL-SDR travel kit consists of. In this post he recommends both our RTL-SDR V3 dongle as well as the NooElec SMArt. For a portable computer, he takes along a Raspberry Pi 3 and a 20,000 mAh battery bank with solar charger. (Though we’d be interested to hear from Akos how long it takes for that small solar panel to charge the battery bank, probably takes days to charge?) For antennas he prefers to take along our large 1.5m telescopic antenna, the NooElec 5dBi ADS-B antenna, a medium telescopic antenna and a Nagoya knock-off telescopic antenna.

Akos' Mobile ADS-B Station.
Akos’ Mobile ADS-B Station.

Finally in the sixth post he shows a video that compares the differences between a generic dongle modded with direct sampling (without any impedance matching circuitry), an RTL-SDR dongle with ham-it-up upconverter and an SDRplay. Unsurprisingly the upconverter and SDRplay performs best.

Direct sampling vs upconverter vs SDRPlay on shortwave broadcast stations - 16 mins

As a bonus, Akos also has done an interesting stress test on the metal case of our RTL-SDR dongles, where he runs it over with a bus to see if it will survive. The case is mangled afterwards, but the dongle and functionality survives!

Dotcom dongle meets a bus

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.

prostickreview_akos2

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

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.

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.

Comparing ADS-B Reception with the RTL-SDR, Airspy and Beast Receivers

Over on satsignal.eu the author has set up a page showing live statistics of his ADS-B reception for the RTL-SDR and Airspy software defined radios, and also for the Beast ADS-B receiver. The Airspy is a $199 software defined radio that many consider as a next stage up from the RTL-SDR, and the Beast is a ~$270 USD dedicated ADS-B receiver.

Unsurprisingly the results clearly show that the Airspy receives ADS-B signals significantly better than the RTL-SDR. However, what comes as a surprise is that it is actually appears to be outperforming the dedicated Beast receiver. In the tests with the outside vertical antenna, the Airspy running on a Raspberry Pi appears to receive a significant higher number of messages and also sees planes out to a further range.

Not too long ago the Airspy team released their ADS-B software for the Raspberry Pi 2. They write that this software uses the full 10 MHz bandwidth and can even decode messages that are overlapping one another. We’ve also been told by the Airspy team that the Airspy is already in professional use as an ADS-B receiver amongst several small airports.

In the future we hope to compare the Airspy against the RTL-SDR on ADS-B reception ourselves, and also compare it against the 8 MHz bandwidth SDRplay whose development team have also recently released a new ADS-B decoder, as well as the recently released FlightAware ADS-B Prostick RTL-SDR.

Beast and Airspy comparison on ADS-B Reception.
Beast and Airspy comparison on ADS-B Reception.