Electrosense+: Global Network of RTL-SDR Sensors with Decoding of FM/AM ADS-B AIS LTE ACARS

Back in late 2019 we posted about the Electrosense network which is an open source project aiming to deploy radio spectrum sensors worldwide. The idea is to help analyze and understand radio spectrum usage across the globe. Each sensor consists of an RTL-SDR, Raspberry Pi and an optional downconverter to receive the higher bands.

Recently Dr. Sofie Pollen wrote in and informed us that they have recently upgraded Electrosense and now users can use any sensor on the network to actually decode signals remotely over a web browser. The currently supported demodulators/decoders include FM/AM, ADS-B, AIS, LTE base station info and ACARS. This makes the Electrosense network kind of similar to the KiwiSDR or OpenWebRX SDR network where there are also various decoders built into the web software.

To test it out you need to create an Electrosense account at electrosense.org. Once logged in, go to "My Electrosense" on the top right, and choose "Spectrum Decoder". You can then choose from a number of Electrosense contributors stationed around the world. Once the waterfall is displayed you can click on signals to decode and listen to them, or change the decoder. Changing to ADS-B or AIS will bring up a map with decoded aircraft or boat positions. Changing to ACARS or LTE will show a text window with the decoded information.

A full electrosense kitset can be purchased from Jetvision, however Sofie notes that they do ship free sensors to some people who cannot afford the kit, and you can apply to increase coverage in your area via this link.

Currently active electrosense sensors
Currently active Electrosense sensors
Electrosense web GUI decoding a wideband FM signal
Electrosense web GUI decoding a wideband FM signal

15 comments

  1. Stu

    Tried it for a while, got “100% occupation” at my address so not exactly a lot of free Hertz for the corporations to grab unless they can petition a land grab like is happening with remote control model airspace up to 400ft.
    I came off it after seeing who was getting the data and would only consider being part something like this if my physical resources and electricity was going toward a more open and consumer focused effort, E.G. record RF exposure and field strength in relation to health but this is not that, by a long shot.
    I too was after the downconverter, I guess they are hard to find because we can’t have the proles knowing what the corps are firing at them.

    • Franco

      Hello,
      The source files of the downconverter are on the github page (In Altium Designer format).
      Nothing prevents you from manufacture the board yourself via Eurocircuit or JLC PCB.
      I can upload also the gerber files to the github if you prefer.

  2. Billy

    Is there somewhere that you can buy, or at least find out the price, for the “optional downconverter”, because to me it looks like the most interesting bit. According to quick scan of the datasheet’s of some parts in the hardware bill of materials (BOM) the tuner (LTC5549), and also after speed reading the source code for the firmware it, can be tuned much higher than advertised (But it would require additional external amplification).

    SW 0 Hz to 27 MHz
    SHF-L 1.5 GHz to 3.5 GHz
    SHF-M 3.5 GHz to 6.5 GHz
    SHF-H 6.5 GHz to 12-1.576 GHz
    SHF-H+ 12-1.576 GHz to 12+1.576 GHz (13.5GHz)

    Since this project is funded by NATO ( https://web.archive.org/web/20200713024149/https://www.networks.imdea.org/research/projects/myp-socrates ), it may not be available as a stand alone item.

      • Martin

        Maybe not in your country, but it is in many others.

        In the UK “Anyone who intentionally and without the necessary authorisation intercepts any communications in the UK may be committing a criminal offence”.

        Fortunately it’s very rarely enforced, unless someone does something really stupid. But the UK is fairly liberal in this respect. In many other countries you could get into serious trouble, even within the EU.

        • John

          From their published paper, all current decoders seems to be for broadcast bands. All of them run on the sensor too. So no raw data transferred. I don’t see anything illegal from a quick look.

          • Martin

            ADS-B, AIS and ACARS classed as Broadcast services ?

            Unfortunately the press and others will pick up on misuse and in some cases it can have serious repercussions.

            e.g. some previous stories.

            https://www.rtl-sdr.com/a-more-in-depth-look-at-the-tunisian-rtl-sdr-espionage-story/

            https://www.rtl-sdr.com/trump-tweets-about-pushed-buffalo-protestor-scanning-to-jam-police-radios-with-an-rtl-sdr-and-android-phone/comment-page-1/

            Terrorists tracking aircraft by ADS-B and ships by AIS have also featured in the popular press in recent years.

            My main issue with the project is that the hobbyists who voluntarily form the network at their own expense and infringing any laws applicable in the host country, may inadvertently end up being scapegoats due to the purposes that the collected data ends up being used for, and also the possibility of others making money from it by activities such as data mining.

            • John

              I agree to some extent. But there are various other successful websites providing full scale ADS-B services, that too in a crowdsourced way (e.g. flightradar, opensky-network). From the privacy policy of Electrosense, it looks like the user data is GDPR protected and can be asked to be deleted anytime. One way or other such networks are inevitable in the future. As long as they address user data privacy issues, I am OK with hosting a sensor. Anyways I agree with your data mining and law infringing part (users are responsible for that for sure).

  3. Martin

    Still a very frustrating application to use despite recent improvements.

    I don’t think there is sufficient return on investment to warrant setting up your own node to provide data to others for no obvious purpose.

    Nice idea, but it’s not for me, in its current form.

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