Every month SDR evangelist Balint Seeber hosts the Cyberspectrum Meetup in San Francisco, where many SDR fans come together to listen to various presentations. The 20th Cyberspectrum SDR meetup has now concluded, and the recorded video is available on YouTube.
Cyberspectrum 20
The talks this time include a very interesting talk by Joe Steinmetz (@usa_satcom) about decoding L-Band weather satellites such as NASA GOES. Previously we made a post regarding GOES where Reddit user devnulling showed his GOES reception setup. To save time, on the video Joe’s talk starts at 00:10:45.
This presentation will cover most aspects of receiving, demodulating and decoding current L-Band Weather Satellite signals (NOAA, MetOp, Meteor, FengYun, GOES). Topics will include hardware, software, de-modulation/decoding techniques, challenges, flows as well as cool sample images and data.
The second talk is titled “Disposable, Stealthy, Cheap SIGINT” is by Chris Kuethe, @kj6gve and delves into topics relating to low cost signal analysis. Chris’ talk starts at 1:45:00. The blurb reads:
This presentation covers some observations and considerations for using inexpensive and compact ARM boards for signals analysis. Topics may include: power budget, air interface, attributability, performance tuning, lolcats and doges.
A few weeks ago we posted about ThumbNets announcement of their new N3 RTL-SDR dongles. The main theme of their new dongles is lower noise as can be seen by their decision to disable the on board switch mode power supply and add an external power port for powering the dongle from a clean power supply.
Akos from the RTLSDR4Everyone blog received a prototype sample of the N3 for an initial review. In his review he shows some close up shots of the N3 PCB, and does a quick test on receiving some signals. His screenshots show that the noise floor is indeed very low, and that many noisy spurs are eliminated or at least significantly reduced.
Once ThumbNet release their actual commercial units we intend to produce our own review as well.
ThumbSat is a company hoping to enable experimenters to get low cost mini satellites into orbit for about $20k. To support the need for global RX of these satellites they have the ThumbNet project which utilizes RTL-SDR dongles as the receiver. They aim to provide schools and eligible volunteers around the world with free RX hardware to receive and record the data coming from these satellites.
Back in September we posted a tutorial that showed how to set up an Outernet receiver with a Raspberry Pi running their rxOS software and an RTL-SDR, LNA and patch antenna. Recently, Outernet have released a new decoder for Windows and Linux which is very easy to install and run. Outernet is an L-band satellite data service which can be received almost anywhere in the world with an RTL-SDR. They aim to be a “library in the sky”, constantly broadcasting public data like news, books, images/videos and other data files.
The new decoder is a Linux machine that runs in a self contained multiplatform Virtual Box virtual machine. This means that it is a standalone package, and it comes included with the OS, decoder, and all the files needed to make it run. Using a virtual machine eliminates any installation issues due to missing dependencies or libraries. Running the VM in Windows is as easy as double clicking on a .exe file to open it up. Note that you’ll need a relatively modern machine that supports hardware virtualization support (VT-x) (Core 2 or newer). The virtual machine itself is lightweight, and uses less than 50MB of RAM, and has very low CPU usage.
At the moment, the decoder writes files downloaded from the Outernet service to a directory stored in C:\Outernet\downloads. Unlike the Raspberry Pi decoder, there is no web interface for accessing the content, though this will probably be added in future builds. The files can be directly accessed in the Windows/Linux file managers.
To set up the VM on a Windows machine:
Download the Windows .exe archive and open it. When prompted, extract the files to a convenient folder on your PC.
Plug in your RTL-SDR and LNA, and set up your L-band antenna.
In the extracted folder run the outernet.exe file once. This will open the decoder and the first time it is run it will automatically create a folder in C:\Outernet.
If you are in the Europe/Africa and use the Alphasat satellite then you can ignore this step. If you are in another region, close the opened VM, then go to C:\Outernet\Satellites.Available, and then copy the file corresponding to the satellite used in your part of the world over to C:\Outernet\Satellites.Selected. Now reopen the outernet.exe VM.
The decoder should now be showing a good SNR value >2 in the top right information, and the State: should show FRAME LK. The bottom right window should also scroll “Packed written to socket.”
After a few minutes check the C:\Outernet\cache folder for pieces of files. Later check the C:\Outernet\downloads folder for completed files.
Further instructions can be found on their Windows Readme file. Note that as there is no web browser for the files, some will be downloaded as GZipped files, and will need to be unzipped to be viewed. For more information on the Outernet service as well as the hardware requirements see our previous tutorial.
We tested out the VM on a Windows laptop for a few hours and was able to receive several GZipped Wikipedia webpages as well as a photo, as shown in the screenshot below.
Files downloaded from Outernet (left). Outernet decoder running in VM (right).
ThumbSat is a company that aims to help experimenters design and launch experiments on their mini satellites (10x smaller than a regular cubesat with most of the same functionality) into orbit. They write that for about $20k they will fully design a satellite based experiment and launch it into orbit – all you need to do is provide the orbital experiment that you would like done.
To aide with the reception, they also have the ThumbNet project which aims to setup a network of satellite receivers around the world. They do this by providing school students around the world with low cost satellite receivers. The satellite receivers consist of modified/upgraded RTL-SDR dongles and satellite antennas.
Today the ThumbNet project announced the latest iteration of their RTL-SDR dongle, called the ThumbNet N3 SDR Receiver. This receiver has some interesting design changes when compared to any other dongle that we’ve seen so far. The biggest change appears to be that this dongle uses an external power port for power. They also replaced the 1.2V switching regulator with a 1.2V linear regulator for lower noise operation. This is useful because switching regulators can cause noise, whilst linear regulators are much cleaner. However, using a linear regulator increases the power consumption significantly, and the new dongle draws 450mA of current (vs 250-280 mA on standard or our V3 dongles), meaning that some USB ports may be unable to power the device unless the external power supply port is used.
The other interesting change is that they have changed the PCB form factor, and it can now fit into a common 1455 aluminum case. Also, similarly to our V3 RTL-SDR dongles, they have decided to add a common mode choke to the USB lines, which significantly reduces USB noise. To add ESD protection they also added a static bleed resistor. Finally, like their previous receivers they continue to use a F-type RF connector and a TCXO for frequency stability.
The price is $25.75 each plus flat rate global shipping of $4.50 and the receivers are expected to ship in mid-October. While we have not yet tested this model, it looks to be like a good receiver for those who need very low noise, or external power options.
They write:
The next Generation, ThumbNet N3 is designed from the ground up to be as simple to use as older generation dongles, but with powerful hardware features for advanced hobbyists and experimenters.
We removed all of the excess components that were sources of noise or interference in other dongles, and optimized the circuit for simplicity, sensitivity and selectability. Then we added a port to use a cable with the extremely common mini-USB connection so that the N3 is less prone to noise from the host computer than a traditional dongle. Finally, the use of standard Surface Mount 0603 or larger components makes it simple for testing or modification.
We built them for our own use, then decided to offer them to everyone.
A quick list of the features of the N3:
– Full backward compatibility with existing RTL-SDR dongles and software – High stability TCXO (+/-0.5ppm) (ensuring rock-solid stability from start-up and over a wide range of temperatures) – Standard R820T2 + RTL2832U (plus 24C02 EEPROM) chipset – Improved/enhanced decoupling. (Common-mode choke on USB port) – Low-noise, linear only power regulation (separate 1.2v and 3.3v regulators) – External DC (+5v, 450mA) supply connector – Mini-USB connection (allows easy separation of the RF unit from the noisy PC) – F type RF connector (very common and compatible with existing ThumbNet tracking stations) – Large (6x4cm) contiguous ground-plane (for better thermal dissipation) – Static drain-away resistor on the RF input (1K to ground) – All unnecessary parts (IR receiver, high-current LED etc.) eliminated to reduce parts count and noise – Circuit board can be mounted into a common 1455 case
Ideal for experimentation:
– Can be connected to an external power supply for very clean power – All of the important tracks are visible on the top side of the board for easy access – All of the RF parts are on the top of the board (only regulators and decouplers on the back) – Logical, simple layout using 0603 (or larger) SMT parts – IF port break in connector (between front end and IF/USB chip) provided
While not required for operation, the N3 receiver is designed to be able to utilize a clean source of power from an external 5v power supply, instead of using the noisy power line coming from the computer’s USB port. This gives a tremendous advantage to the purist or experimenter who wants to utilize power from the N3 to power any external experiments. (When the external power supply is active, no power is drawn from the USB port to power the N3.)
PLEASE NOTE: The N3 draws approximately 450mA of current and care should be taken, even when using a powered USB hub, as it could possibly exceed the current limit of the USB port.
The ThumbNet N3The ThumbNet N3 inside its optional 1455 aluminum enclosure.
Over on hackaday.io there is a project blog for the “Distributed Ground Station Network”. This is essentially an idea to build a large network of distributed RF receivers which automatically receive signals from sources like cube satellites and other beacons. The project mainly uses RTL-SDR dongles at the moment for their RF receivers. In some ways it appears to be similar to the SatNOGs project which won the hackaday prize two years ago but the DGSN appears to be more focused on “reverse GPS” which allows the detection and tracking of the location of small satellite signals through distributed receivers.
They write:
The Distributed Ground Station Network (DGSN) is a novel network concept of small ground-stations and connected via the internet for performing automatic scans for cubesats and other beacon signals. By correlating the received signal with the precise, GNSS synchronized reception times of at least 5 ground stations, it enables the positioning of the signal’s origin. Thus a global tracking of small satellites becomes possible in this “reverse GPS” mode. It allows mission operators to position and track their small satellites faster after piggy-back commissioning, when the final orbit is yet undefined and could differ from the specified orbit. Furthermore it allows permanent communication in “data-dump” mode. In this mode, DGSN ground-stations relay the received data to the servers and thus to the operator. Let’s track everything, together!
NOTE: This tutorial is no longer valid as Outernet discontinued their L-Band service in late 2017. Please consult www.outernet.is for news on their latest delivery methods.
Outernet is a relatively new satellite service which aims to be a "library in the sky". Essentially their service is going to be constantly transmitting files and data like news and weather updates from geostationary satellites that cover almost the entire world. Geostationary means that the satellites are in a fixed position in the sky, and do not move over time. By simply pointing a small patch antenna at the sky (with LNA and RTL-SDR receiver), it is possible to download and decode this data from almost anywhere in the world. Their aim is to provide up to date information to users in locations with little to no internet (rural, third world and sea), or in countries with censored internet. It may also be of interest to disaster preppers who want an "off-grid" source of news and weather updates. It can kind of be thought as a kind of one-way download-only internet service.
Currently the L-band service is being tested, and while they are not yet sending actual Outernet files, they are already sending several daily test files like small videos, images and text documents as well as GRIB files for mariners. At a maximum you can expect to receive up to about 20 MB of data a day from their satellite. Previously they had C-band services but these required large satellite dishes. The C-band service is due to be discontinued at some point in the future.
In this guide we'll show you how to set up an Outernet L-band receiver with an RTL-SDR dongle. If you enjoy this guide then you might also enjoy our Inmarsat STD-C EGC Decoding Tutorial which has similar hardware requirements.
Every month SDR evangelist Balint Seeber hosts the Cyberspectrum Meetup in San Francisco, where many SDR fans come together to listen to various presentations. The 20th Cyberspectrum SDR meetup has now concluded, and the recorded video is available on YouTube.
Cyberspectrum 20
The talks this time include a very interesting talk by Joe Steinmetz (@usa_satcom) about decoding L-Band weather satellites such as NASA GOES. Previously we made a post regarding GOES where Reddit user devnulling showed his GOES reception setup. To save time, on the video Joe’s talk starts at 00:10:45.
This presentation will cover most aspects of receiving, demodulating and decoding current L-Band Weather Satellite signals (NOAA, MetOp, Meteor, FengYun, GOES). Topics will include hardware, software, de-modulation/decoding techniques, challenges, flows as well as cool sample images and data.
The second talk is titled “Disposable, Stealthy, Cheap SIGINT” is by Chris Kuethe, @kj6gve and delves into topics relating to low cost signal analysis. Chris’ talk starts at 1:45:00. The blurb reads:
This presentation covers some observations and considerations for using inexpensive and compact ARM boards for signals analysis. Topics may include: power budget, air interface, attributability, performance tuning, lolcats and doges.
A few weeks ago we posted about ThumbNets announcement of their new N3 RTL-SDR dongles. The main theme of their new dongles is lower noise as can be seen by their decision to disable the on board switch mode power supply and add an external power port for powering the dongle from a clean power supply.
Akos from the RTLSDR4Everyone blog received a prototype sample of the N3 for an initial review. In his review he shows some close up shots of the N3 PCB, and does a quick test on receiving some signals. His screenshots show that the noise floor is indeed very low, and that many noisy spurs are eliminated or at least significantly reduced.
Once ThumbNet release their actual commercial units we intend to produce our own review as well.
ThumbSat is a company hoping to enable experimenters to get low cost mini satellites into orbit for about $20k. To support the need for global RX of these satellites they have the ThumbNet project which utilizes RTL-SDR dongles as the receiver. They aim to provide schools and eligible volunteers around the world with free RX hardware to receive and record the data coming from these satellites.
Back in September we posted a tutorial that showed how to set up an Outernet receiver with a Raspberry Pi running their rxOS software and an RTL-SDR, LNA and patch antenna. Recently, Outernet have released a new decoder for Windows and Linux which is very easy to install and run. Outernet is an L-band satellite data service which can be received almost anywhere in the world with an RTL-SDR. They aim to be a “library in the sky”, constantly broadcasting public data like news, books, images/videos and other data files.
The new decoder is a Linux machine that runs in a self contained multiplatform Virtual Box virtual machine. This means that it is a standalone package, and it comes included with the OS, decoder, and all the files needed to make it run. Using a virtual machine eliminates any installation issues due to missing dependencies or libraries. Running the VM in Windows is as easy as double clicking on a .exe file to open it up. Note that you’ll need a relatively modern machine that supports hardware virtualization support (VT-x) (Core 2 or newer). The virtual machine itself is lightweight, and uses less than 50MB of RAM, and has very low CPU usage.
At the moment, the decoder writes files downloaded from the Outernet service to a directory stored in C:\Outernet\downloads. Unlike the Raspberry Pi decoder, there is no web interface for accessing the content, though this will probably be added in future builds. The files can be directly accessed in the Windows/Linux file managers.
To set up the VM on a Windows machine:
Download the Windows .exe archive and open it. When prompted, extract the files to a convenient folder on your PC.
Plug in your RTL-SDR and LNA, and set up your L-band antenna.
In the extracted folder run the outernet.exe file once. This will open the decoder and the first time it is run it will automatically create a folder in C:\Outernet.
If you are in the Europe/Africa and use the Alphasat satellite then you can ignore this step. If you are in another region, close the opened VM, then go to C:\Outernet\Satellites.Available, and then copy the file corresponding to the satellite used in your part of the world over to C:\Outernet\Satellites.Selected. Now reopen the outernet.exe VM.
The decoder should now be showing a good SNR value >2 in the top right information, and the State: should show FRAME LK. The bottom right window should also scroll “Packed written to socket.”
After a few minutes check the C:\Outernet\cache folder for pieces of files. Later check the C:\Outernet\downloads folder for completed files.
Further instructions can be found on their Windows Readme file. Note that as there is no web browser for the files, some will be downloaded as GZipped files, and will need to be unzipped to be viewed. For more information on the Outernet service as well as the hardware requirements see our previous tutorial.
We tested out the VM on a Windows laptop for a few hours and was able to receive several GZipped Wikipedia webpages as well as a photo, as shown in the screenshot below.
Files downloaded from Outernet (left). Outernet decoder running in VM (right).
ThumbSat is a company that aims to help experimenters design and launch experiments on their mini satellites (10x smaller than a regular cubesat with most of the same functionality) into orbit. They write that for about $20k they will fully design a satellite based experiment and launch it into orbit – all you need to do is provide the orbital experiment that you would like done.
To aide with the reception, they also have the ThumbNet project which aims to setup a network of satellite receivers around the world. They do this by providing school students around the world with low cost satellite receivers. The satellite receivers consist of modified/upgraded RTL-SDR dongles and satellite antennas.
Today the ThumbNet project announced the latest iteration of their RTL-SDR dongle, called the ThumbNet N3 SDR Receiver. This receiver has some interesting design changes when compared to any other dongle that we’ve seen so far. The biggest change appears to be that this dongle uses an external power port for power. They also replaced the 1.2V switching regulator with a 1.2V linear regulator for lower noise operation. This is useful because switching regulators can cause noise, whilst linear regulators are much cleaner. However, using a linear regulator increases the power consumption significantly, and the new dongle draws 450mA of current (vs 250-280 mA on standard or our V3 dongles), meaning that some USB ports may be unable to power the device unless the external power supply port is used.
The other interesting change is that they have changed the PCB form factor, and it can now fit into a common 1455 aluminum case. Also, similarly to our V3 RTL-SDR dongles, they have decided to add a common mode choke to the USB lines, which significantly reduces USB noise. To add ESD protection they also added a static bleed resistor. Finally, like their previous receivers they continue to use a F-type RF connector and a TCXO for frequency stability.
The price is $25.75 each plus flat rate global shipping of $4.50 and the receivers are expected to ship in mid-October. While we have not yet tested this model, it looks to be like a good receiver for those who need very low noise, or external power options.
They write:
The next Generation, ThumbNet N3 is designed from the ground up to be as simple to use as older generation dongles, but with powerful hardware features for advanced hobbyists and experimenters.
We removed all of the excess components that were sources of noise or interference in other dongles, and optimized the circuit for simplicity, sensitivity and selectability. Then we added a port to use a cable with the extremely common mini-USB connection so that the N3 is less prone to noise from the host computer than a traditional dongle. Finally, the use of standard Surface Mount 0603 or larger components makes it simple for testing or modification.
We built them for our own use, then decided to offer them to everyone.
A quick list of the features of the N3:
– Full backward compatibility with existing RTL-SDR dongles and software – High stability TCXO (+/-0.5ppm) (ensuring rock-solid stability from start-up and over a wide range of temperatures) – Standard R820T2 + RTL2832U (plus 24C02 EEPROM) chipset – Improved/enhanced decoupling. (Common-mode choke on USB port) – Low-noise, linear only power regulation (separate 1.2v and 3.3v regulators) – External DC (+5v, 450mA) supply connector – Mini-USB connection (allows easy separation of the RF unit from the noisy PC) – F type RF connector (very common and compatible with existing ThumbNet tracking stations) – Large (6x4cm) contiguous ground-plane (for better thermal dissipation) – Static drain-away resistor on the RF input (1K to ground) – All unnecessary parts (IR receiver, high-current LED etc.) eliminated to reduce parts count and noise – Circuit board can be mounted into a common 1455 case
Ideal for experimentation:
– Can be connected to an external power supply for very clean power – All of the important tracks are visible on the top side of the board for easy access – All of the RF parts are on the top of the board (only regulators and decouplers on the back) – Logical, simple layout using 0603 (or larger) SMT parts – IF port break in connector (between front end and IF/USB chip) provided
While not required for operation, the N3 receiver is designed to be able to utilize a clean source of power from an external 5v power supply, instead of using the noisy power line coming from the computer’s USB port. This gives a tremendous advantage to the purist or experimenter who wants to utilize power from the N3 to power any external experiments. (When the external power supply is active, no power is drawn from the USB port to power the N3.)
PLEASE NOTE: The N3 draws approximately 450mA of current and care should be taken, even when using a powered USB hub, as it could possibly exceed the current limit of the USB port.
The ThumbNet N3The ThumbNet N3 inside its optional 1455 aluminum enclosure.
Over on hackaday.io there is a project blog for the “Distributed Ground Station Network”. This is essentially an idea to build a large network of distributed RF receivers which automatically receive signals from sources like cube satellites and other beacons. The project mainly uses RTL-SDR dongles at the moment for their RF receivers. In some ways it appears to be similar to the SatNOGs project which won the hackaday prize two years ago but the DGSN appears to be more focused on “reverse GPS” which allows the detection and tracking of the location of small satellite signals through distributed receivers.
They write:
The Distributed Ground Station Network (DGSN) is a novel network concept of small ground-stations and connected via the internet for performing automatic scans for cubesats and other beacon signals. By correlating the received signal with the precise, GNSS synchronized reception times of at least 5 ground stations, it enables the positioning of the signal’s origin. Thus a global tracking of small satellites becomes possible in this “reverse GPS” mode. It allows mission operators to position and track their small satellites faster after piggy-back commissioning, when the final orbit is yet undefined and could differ from the specified orbit. Furthermore it allows permanent communication in “data-dump” mode. In this mode, DGSN ground-stations relay the received data to the servers and thus to the operator. Let’s track everything, together!
NOTE: This tutorial is no longer valid as Outernet discontinued their L-Band service in late 2017. Please consult www.outernet.is for news on their latest delivery methods.
Outernet is a relatively new satellite service which aims to be a "library in the sky". Essentially their service is going to be constantly transmitting files and data like news and weather updates from geostationary satellites that cover almost the entire world. Geostationary means that the satellites are in a fixed position in the sky, and do not move over time. By simply pointing a small patch antenna at the sky (with LNA and RTL-SDR receiver), it is possible to download and decode this data from almost anywhere in the world. Their aim is to provide up to date information to users in locations with little to no internet (rural, third world and sea), or in countries with censored internet. It may also be of interest to disaster preppers who want an "off-grid" source of news and weather updates. It can kind of be thought as a kind of one-way download-only internet service.
Currently the L-band service is being tested, and while they are not yet sending actual Outernet files, they are already sending several daily test files like small videos, images and text documents as well as GRIB files for mariners. At a maximum you can expect to receive up to about 20 MB of data a day from their satellite. Previously they had C-band services but these required large satellite dishes. The C-band service is due to be discontinued at some point in the future.
In this guide we'll show you how to set up an Outernet L-band receiver with an RTL-SDR dongle. If you enjoy this guide then you might also enjoy our Inmarsat STD-C EGC Decoding Tutorial which has similar hardware requirements.
At this year’s hacker themed Eleventh Hope conference, Stefan “Sec” Zehl and Schneider gave a talk which discusses their latest work on decoding data from Iridium satellites using SDR’s. Iridium is a truly global satellite service which provides various services such as global paging, satellite phones, tracking and fleet management services, as well as services for emergency, aircraft, maritime and covert operations too. There are currently 72 operational satellites operating.
In their talk they discuss how Iridium security is moderate to relaxed, pointing out that Iridium claims that the majority of ‘security’ comes from the complexity of the system, rather than actual security implementations. They then go on to discuss how the Iridium system works, how to receive it with an RTL-SDR or HackRF/Rad1o, how the gr-iridium decoder implementation works, and how to use it to actually decode the data. Later in the presentation they show some interesting examples such as an intercepted Iridium satellite phone call to a C-37 aircraft.
A few days ago we posted a review on the Outernet LNA which can can be used to help receive their new L-band service signal. Their LNA uses a filter which restricts the frequency range from 1525 – 1559 MHz as this is the range in which the Outernet signals are located.
Additional Note Regarding the Downconverter: Also, it appears that the Outernet downconverter prototype that we posted about back in May has unfortunately been discontinued indefinitely and will not enter mass production. For now the LNA is the best option for receiving their signal.
