Category: Applications

ADS-B Onboard a 737 with Realtime Primary Flight and Navigation Display

Recently we found this video from 2013 on YouTube by user carcharias04 showing an RTL-SDR being used for ADS-B on board a 737-800 commercial jet. In the video he uses a custom program that interfaces with RTL1090 and XHSI, which is a navigation display program for the popular flight simulator known as X-Plane.

With his RTL-SDR, RTL1090, his custom software and XHSI running he is able to see a real time display of the primary flight and navigation displays which are the same or similar to the instruments used by the pilots in the cockpit.

Unfortunately, it seems like the uploaders custom interface program is not available anywhere that we know of.

Update 1: The software is this interface available on GitHub. Schumann-resonance from the comments section has uploaded a precompiled binary file here http://www57.zippyshare.com/v/49667810/file.html.

Update 2: To get it to work you need to first set the Table 2 name in RTL1090 to “tableb”, then run RTL1090 first before opening RTL1090-XHSI. Then enter the ICAO of the flight you’d like to use in the text box at the top of the interface window. Now data should begin to appear in the RTL1090-XHSI Window. Now you can open XHSI and it should automatically begin using the ADS-B data.

RTL1090 ADSB live on board Boeing 737-800

Decoding the Russian Parus (Cosmos) Navigation Satellites with the RTL-SDR

Once again Happysat, who previously wrote in to RTL-SDR.com to let us know how to receive dead satellites with the RTL-SDR has again written in to let us know about his latest achievements.

Happysat has recently been using a RTL-SDR to decode the discontinued Russian Parus (Cosmos) Navigation Satellites. These are low earth orbit satellites operated by the Russian Space Forces that are used for military communication and navigation. Since 1974 there have been 99 Parus satellites launched, but there are only three currently active.

With an RTL-SDR, SDR# and decoder software, Happysat was able to decode data from the satellite which includes the current Moscow time and various location and telemetry data.

Russian Parus (Cosmos) Satellite Decoded Data
Russian Parus (Cosmos) Satellite Decoded Data

Happysat writes:

The Russian Military Parus satellites are/where used for low-earth orbiting navigation information and store-dump radio communications relay service for Red Navy surface vessels and submarines.

Each satellite is in a near-circular orbit of about 1000 km (620 miles).The orbits are polar (pass over the poles of the earth) and stay stationary in space so that as the earth rotates, the satellite covers different parts of the planet.

There are three currently operational, Cosmos 2407, 2414, and the last one launched in this series (April 2012) Cosmos 2463 with a lifespan of 4 years.

They are discontinued now as the GLONASS Navigation systems did take over the service which are providing a better accurate GPS position.

Why the Parus-Satellites are currently still broadcasting data is unknown. Most probably due the older vessels and submarines are still using Shkhuna Radio systems.

The satellites transmit two radio carriers, one on VHF which is FM modulated with the navigational data around 10 watts, and one on UHF which is unmodulated (tracking Beacon).

Already in 1980 the British Kettering Group was able to decode the encryption. The first 18 Bit of data contain the Moscow time, the other Bits contain the positions and orbits from the other active Parus-Satellites. Very similar data like our GPS output and the Orbcomm satellites (on 137 Mhz) with OrbcommPlotter (explained also on rtl-sdr).

With RTL-SDR and SDRSharp its possible also to decode the Russian Military Parus satellites.

Alan Cordwell did write a Java decoder that will decode the navigation data from the VHF transmission in non-real time. cosmos_export.rar [Mirror] It is experimental software and very basic.

Unfortunately his website is offline but still on web-archive (link to web archive)

You will need to record the audio from the satellite and save it as a 44100, 8-bit, mono .wav file. Which means SDRSharp included wave recording is not suitable to do this you need a external program like Audacity or any favourite which can handle the requirements above.

Then you will need to apply narrow bandpass filtering to it at 3, 5 and 7 kHz. Without this filtering step only a small portion of the data will be available, i’m still struggling with this step 😉

He did use Cool Edit Pro to do this, there are no doubt other apps available like Audacity. Included is a sample filtered audio file for you to try it with, it’s in the rar archive as well.

Unpack the archive to a convenient location a folder called cosmos-export will result. Execute the file cosdec.jar to run the application. Open a file with file/open and in the file chooser dialog select the wav file. To decode it go to Actions/Process File.

To write all output to a log file: check the Dump to log option in File menu (log file will be created with same name as audio file but with .log extension appended). Datascope does as it suggests; it launches a little frame that shows (using graphics) the waveform of the data recovered from the audio. The frequency axis is upside down! you’ll see the 3, 5 and 7kHz bits with 7 at the bottom.

There is another program (Sorcerer) which can decode in real-time only, the current actual atom Moscow time from the satellites.

[sorcer download]

Start sorcerer and go to the menu add decoder on the left FSK and choose COSMOS NAVDATA. Move the first bar slider in the spectrum to 3 kHz so the second and third are on 5 and 7 KHz as seen in the screenshot.

Its possible to run this application and record audio at the same time which is later on needed for the cosmos_export Java program.

The frequencies are as follows:

Cosmos 2407 and 2414
VHF Frequency NavData 149.970 MHz, Tracking Beacon 399.920MHz

Cosmos 2463
VHF Frequency NavData 149.940 MHz Tracking Beacon 399.840MHz

Orbital parameters and predictions:

You need to run Orbitron in SDRSharp to take care of the Doppler!

TLE’s for the current satellites, (these are current as of 10th November 2014)

COSMOS 2407
1 28380U 04028A   14313.17698750  .00000073  00000-0  59418-4 0  2927
2 28380  82.9601 332.2565 0038129 220.5020 139.3308 13.75978622517201

COSMOS 2414
1 28521U 05002A   14314.08629907  .00000094  00000-0  65641-4 0  6502
2 28521  82.9510   6.9860 0040501 164.6577 195.5838 13.87513505496523

COSMOS 2463
1 36519U 10017A   14313.57202739 -.00000009  00000-0 -27079-4 0  4041
2 36519  82.9553 122.2841 0036820   7.8477 352.3245 13.71357663227175

New ones can be downloaded at celestrak: musson.txt

Good luck and if anyone has good knowledge on how to apply narrow bandpass filtering at 3, 5 and 7 kHz, please write in the comments!

Note that Orbitron can be downloaded from http://www.stoff.pl/, and the SDR# plugin to interface with it can be downloaded from SatelliteTracker2.zip or here. A tutorial on using Orbitron with SDR# for Doppler correction can be found on our NOAA Weather satellite reception tutorial.

SDR# with Orbitron for Doppler Correction and Sorcerer for Decoding Cosmos
SDR# with Orbitron for Doppler Correction and Sorcerer for Decoding Cosmos
Image of the Russian Parus Satellite
Image of the Russian Parus Satellite
Image of the Russian Parus Satellite
Image of the Russian Parus Satellite
Which option to choose in Sorcerer
Which option to choose in Sorcerer

Receiving Dead Satellites with the RTL-SDR

Recently happysat, a reader of RTL-SDR.com wrote in to let us know about an unusual hobby he has found with the RTL-SDR. Happysat has been using the RTL-SDR together with a QFH antenna to detect old decommissioned satellites in the 136-138 MHz and 150-400 MHz frequency ranges. Although these satellite’s batteries have long been expired, because of some sort of chemical reaction due to thousands of failed recharge cycles the batteries begin to conduct over time and allow the satellite to be powered directly from the solar panels thus activating the transmitter. Happysat writes:

During weathersat reception of NOAA/Meteor on the 137 MHz band i did see quite often unidentified interrupting signals. After a bit of Googling around I learned that these were Dead Satellite’s that still are broadcasting given the right sunlight conditions, the signal strength is sufficient to show up in SDRSharp, not all signals are very strong some very weak and needed a good close up zoom in SDRSharp. There are many shutdown Satellite’s who apparently having a life of their own varying from Military, Navigation, Experimental, Weather, and also Amateur ones. Most are not transmitting any usable telemetry or weather images but they still use the original frequencies to sent out a unmodulated carrier, which interferes with the current operational Satellite’s in the 136/138 MHz band. Normally when a satellite goes out of service and runs almost out of fuel the last reserve is used to shift it in a graveyard orbit which resides above the normal operation orbit, it will be switched off and left on their own. But this will not always goes as planned, sometimes due solar radiation or other technical failures it will not respond again to the ground station commands, which leaves the Satellite in its current orbit. Some have a timer onboard which will be activated at end of life scheduled to end/shortcut the power feed to the transmitter so it will not broadcast again, also this can fail. Until some day they might not work at all anymore.. But that can take a while one of the oldest satellite still broadcasting are: Transit 5B-5 (Military Navigation) from 1964 – they can be heard in either CW or USB mode. An audio example of Transit is over here [link to example] (my recording – link to online stream  uploaded by commenter Jordan here) it sounds like some kind of melody song. And LES-1 from 1965 (Lincoln Experimental Satellite 1) – Audio example over here [link to example] thanks to Phil Williams. Others are just a spooky hauling sound like LES-1, NOAA’s etc due the Voltage fluctuation from the solar panels. DD1US does have a very nice collection images and orginal sounds on : [space sounds] A list of frequencies and more in depth details can be found on Mike Kenny’s excellent website: [mike kenny’s website] My TLE containing all current Deadsatellite’s is available on dropbox for anyone would like to try out – [TLE file] Updated once a week. You can use it in your favorite tracker, i prefer Gpredict for this course of the unstable frequency and Doppler effects Orbitron will not always suite on this birds.

Happysat has also provided a frequency database for SDR# containing the frequencies of all the dead satellites.

Aloutte
Aloutte
Transit 5B
Transit 5B
Transit 5B
Transit 5B
Tiros-N
Tiros-N
NOAA-9
NOAA-9
NOAA-9
NOAA-9
LES-1
LES-1
ISIS-1
ISIS-1
GPredict
GPredict
Fenyung 1D
Fenyung 1D

 

Receiving Hellschreiber with the RTL-SDR and an Upconverter

Over on YouTube user BSoD Badgers has uploaded a video showing reception of Hellschreiber on HF at 20m. To receive the HF frequencies he used a ham-it-up upconverter. He used SDR# to receive the signal and the Fldigi decoding software to decode the signal.

Hellschreiber is a fax-like communications mode used by amateur radio hobbyists.

Using the HackRF on Android

Micheal Ossmann’s HackRF Linux library has recently been ported to Android by programmer Dennis Mantz. Dennis has also made a blog post showing how to use the library. In addition he’s uploaded a YouTube video showing off the library using an example app. The app is capable of recording an RF signal and replaying it via the HackRF’s TX capabilities. In the video Dennis shows the example app recording a broadcast FM station and then retransmitting the recording to his car radio.

Using the HackRF on an Android Device

Hak5: Mobile SDR Apps

On this episode of Hak5, a popular YouTube technology channel, Shannon shows two Android based ADS-B RTL-SDR apps that we have mentioned on this blog previously. One is “ADS-B on USB SDR RTL” and the other is Avare ADS-B. Both are ADS-B apps that will display real time airplane positions on a map.

To run these apps you need a RTL-SDR dongle, a USB OTG cable and an Android phone.

Cellular Testing Tools and Mobile SDR Apps, Hak5 1708

Raspberry Pi RTL-SDR Spectrum Analyzer Scanner

Adafruit has released a tutorial showing how to build a portable TFT screen based Raspberry Pi RTL-SDR spectrum analyzer that was inspired by the HackRF portapack. Construction of the project is very simple and the “FreqShow” python software is provided as a simple download that is ready to run once the RTL-SDR is installed on the Raspberry Pi.

The FreqShow software appears to be fully featured with the ability to change the center frequency, sample rate, and gain.  It can show on the TFT screen the real time RF spectrum of the currently tuned area or it can be switched to show a waterfall of the spectrum as well. Below is a video of the finished project that shows the software in action.

"Freq Show" Software in action on a Raspberry Pi
“Freq Show” Software in action on a Raspberry Pi with TFT Screen

SDR(X): New Upconverter for the RTL-SDR

A new UK designed and manufactured upconverter that goes by the name SDR(X) has recently become available for purchase. This upconverter connects to a RTL-SDR dongle and allows it to receive from 100 kHz up till 1850 MHz. Some of its features include:

  • Four user selectable HF pre-filters (0-2, 2-6, 6-11 and 11 to 30MHz) or single 0-30MHz pre-filter.
  • Band pass filter after mixer and band pass filter after Oscillator
  • User selectable MMIC 18db amplifier external to RTL chip set (lower noise level, than RTL chip and compensates for pre-filters).
  • User selectable HF and VHF/UHF mode (HF 0-30MHz, VHF/UHF mode 24MHz to 1850MHz).
  • Microchip PIC controller for above.
  • Diode protection on RF input.

The board comes as a prebuilt kit which is currently selling for 79.95 GBP which includes an RTL-SDR dongle. The device also comes with complete documentation. The SDR(X) can be purchased from 6v6.co.uk.

Image of the SDR(X)
Image of the SDR(X)