Over on YouTube TechMinds has uploaded a video showing how to use the Iridium Toolkit software to receive data and audio from Iridium satellites with an Airspy. Iridium is a global satellite service that 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. It consists of multiple low earth orbit satellites where there is at least one visible in the sky at any point in time, at most locations on the Earth.
The frequencies used by the older generation Iridium satellites are in the L-band, and the data is completely unencrypted. That allows anyone with an RTL-SDR or other SDR radio to decode the data with the open source Iridium Toolkit. If you're interested in how Iridium Toolkit was developed, see this previous post about Stefan "Sec" Zehl and Schneider's 2016 talk.
In the video Tech Minds shows decoding of various data, including an audio call and the satellite tracks and heat map of Iridium satellites.
We just wanted to note that this Monday the reduced preorder pricing of US$130 + shipping will end, and the price will rise to the retail price of $149.95 + shipping. So if you have been thinking about ordering a unit, now would be a good time. Ordering is currently possible through Indiegogo. On Monday we will change to our own store. EDIT: Now available to purchase on the Othernet Store.
For shipping, US orders will be sent domestically from Othernet's office in Chicago. They are still waiting on the US shipment to arrive, but it is expected to arrive by the end of next week. Once shipped locally you will receive a shipment notification.
For international orders, the packages are being labelled now, and should be going out early next week, or sooner.
KerberosSDR Inside and Outside the Enclosure
Future Updates to KerberosSDR
With the profits raised from KerberosSDR sales we are looking to continue funding development on the open source server software and visualization software being created (as well as applying updates ourselves). In future updates we will be looking at features such as:
Streamlining the sample and phase sync calibration process.
Experimenting with software notch filters for calibration (may reduce the need to disconnect the antennas during calibration).
Reworking the buffering code for improved sample ingestion performance and increased averaging.
Direction finding and passive radar algorithm improvements.
Creating a networked web application for combining data from two or more physically distributed KerberosSDRs over the internet for immediate TX localization.
Updates and bug fixes for the Android mobile direction finding app for use in vehicles.
Improving passive radar to be able to use all four RX ports for surveillance so that larger areas can be covered.
Plotting passive radar pings on a map.
Beginning experimentation with beam forming.
In the farther future we hope to eventually have even more clever software that can do things like locate multiple signals in the bandwidth at once, automatically plot them on a map, and track them via their unique RF fingerprint, or other identifiers.
Future hardware updates may see more streamlined calibration and smaller sizes.
Over on Reddit user u/isysopi201 has put up a fun post showing what an RTL-SDR Blog V3 looks like under an X-Ray machine. With the full resolution images, it is possible to see the PCB traces in internal planes, the windings on the electrolytic capacitor, inductors, USB choke and direct sampling matching transformer, as well as the bond wires on the RTL2832U and R820T2 silicon chips that connect the pins to the silicon.
Rodrigo's system consists of an IF tap amplifier+filter board that is connected to an internally mounted RTL-SDR. The RTL-SDR is internally connected to the FT-991A's USB hub which had to be upgraded from a 2-port hub to a 4-port hub as the 2-ports were already in use by the CAT and Audio features. This required the stock USB hub IC to be replaced with a hot air rework station.
Everything is mounted inside the radio chassis itself, and the end result is a neat solution with no external wires, hubs or dongles that has essentially turned the FT-991A into an SDR. Plugging in the single stock USB cable from the FT-991A results in the standard CAT and Audio interfaces showing up, as well as the RTL-SDR.
What's also interesting is that Rodrigo makes use of the GPIO pins on our RTL-SDR Blog V3 to enable the RX_EN, BPF and BYPASS switches on the IF tap board. This allows for a cleaner solution as no external switches need to be installed.
The entire project is open source with schematics and the BOM provided over on the GitHub, and excellent documentation is available on the project's Wiki.
FT991A Converted into an SDR.
Turning FT-991A to a REAL SDR: Embedding a SDR Panadapter INSIDE the radio, no extra wires!
This week on the SignalsEverywhere YouTube channel Harold shows us the mobile SDR and ham radio setup that he's installed on his car. On the roof of his car he's installed several antennas for various amateur radio bands including the 1.25m, 2m, 70cm, 33cm bands, a modified GPS puck antenna for Inmarsat and Iridium reception, and an antenna and GPS pick dedicated for APRS.
Inside the vehicle is a Windows tablet attached to the dashboard which is used for APRS, remotely controlling a scanner radio stored in the trunk and for running SDRSharp. There is also an Android unit installed in the center console which has an RTL-SDR connected. The Android unit runs RF Analyzer, and an ADS-B decoder. As well as SDRs, Harold also runs several standard ham radios within the vehicle.
Amateur Radio Mobile SDR Load Out | SDR Plus 33cm 70cm 2m 1.25m and more!
Arun Venkataswamy has recently completed a write up about his system which automatically captures images of passing aircraft. It works by using a Raspberry Pi and RTL-SDR to listen to ADS-B broadcasts from aircraft. These broadcasts contain the live current location and altitude of all aircraft in his area. When a landing aircraft is detected to be passing near his house, the Raspberry Pi sends a signal to another Raspberry Pi connected to a camera on his balcony, and that snaps a photo of the passing aircraft.
In terms of software, Arun uses dump1090 as the ADS-B decoder. For communications between the two Raspberry Pi's he uses Node-RED and Mosquitto in order to communicate with MQTT. On the second Raspberry Pi, gPhoto2 captures images from the camera, and then ImageMagick is used to write some text about the aircraft and photo on the image. Arun's post goes in further detail about the code and conditions he uses to determine when a photo should be snapped.
In the past we've posted about a similar project where an RTL-SDR and Raspberry Pi based ADS-B tracker was used with a servo mounted video camera to track and record video of passing aircraft.
Automatically Taking Photos of Passing Aircraft with a Raspberry Pi and RTL-SDR
SDR-Kits.net have begun selling low cost GPS antennas that are modified to receive the Inmarsat satellite frequencies between 1535 MHz to 1550 MHz. They also have a version for Iridium satellites that receives 1610 MHz to 1630 MHz. The antennas are powered by a 3-5V bias tee, so they should work fine with SDRplay, Airspy and RTL-SDR Blog V3 units.
AERO messages are a form of satellite ACARS, and typically contain short messages from aircraft. It is also possible to receive AERO audio calls. STD-C aka FleetNET and SafetyNET is a marine service that broadcasts messages that typically contain text information such as search and rescue (SAR) and coast guard messages as well as news, weather and incident reports. Some private messages are also seen. To decode AERO Mike uses JAERO, and for STD-C he uses the Tekmanoid STD-C decoder.
Mike has also created a very handy bank of frequencies for the SDRUno frequency manager which can be downloaded from here.
We note that if you're interested in waiting, at the end of September we will have an L-band patch antenna set available too. Our antenna will work from 1525 up to 1637 MHz. Prototypes have shown have shown good Inmarsat, Iridium and GPS reception. More details coming next month when manufacturing gets closer to finishing up.
Screenshot of the Tekmanoid Decoder from Mikes Tutorial
Over on GitHub user mcogoni (Marco/IS0KYB) has recently released a new program called Pepyscope. Pepyscope is a simple and fast panadapter application that is designed to be used with direct sampling capable RTL-SDR's such as our RTL-SDR Blog V3 units. Like other panadapters you simply connect the IF output from the hardware HF radio into the input of the RTL-SDR. Then Pepyscope gives you a waterfall display that helps users to easily visualize the spectrum.
Pepyscope is open source and runs on Linux PCs. So far Marco has tested Pepyscope with a KENWOOD TS-180S (single conversion with IF at 8.83 MHz) and an RTL-SDR v3. He has also uploaded a demonstration video on YouTube.
