Echoes: An RTL-SDR Tool for Meteor Scatter Detection

Echoes Running
Echoes Running

Thanks to "gmbertani" for letting us know about his recently released RTL-SDR compatible software called "Echoes". Echoes is a Windows, Linux and Raspberry Pi/Arch compatible tool that can be used together with an RTL-SDR and appropriate antenna to monitor for meteor scatter detections.

Meteor scatter works by receiving a distant but powerful transmitter via signal reflections off the trails of ionized air that meteors leave behind when they enter the atmosphere. Normally the transmitter would be too far away to receive, but if its able to bounce off the ionized trail in the sky it can reach far over the horizon to your receiver. Typically powerful broadcast FM radio stations, analog TV, and radar signals at around 140 MHz are used. By listening to these signal blips it can be possible to estimate the number of meteors falling.

Below we paste the official description and feature list of Echoes, and at the end is a video demonstrating Echoes in action:

Echoes it's a radio spectral analysis software for RTL-SDR devices, designed for meteor scattering purposes.

Echoes doesn't demodulate neither decode any human-made signal. Its main goal is to analyze and record the total power of natural signals and generate screenshots and tabular data (CSV, GNUplot) output in presence of particular peaks in a selected narrow range of frequencies. Since there is no demodulation, there is no provision for audio listening, except for a notify sound when an event has been recorded.


  • Captures waterfall spectra as PNG screenshots and statistics data files.
  • Optionally generates GNUplot data files
  • Multiple instances can manage separate dongles plugged in the same computer
  • Three operating modes: continuos (records data only), periodic (captures data and screenshot every X seconds) and automatic (record data and screeshot each time a customizable (S-N) treshold is exceeded)
  • HTML report production
  • Installers ready for Windows7++ and RPMs / SRPMs for Linux
  • xz binary package for Raspberry PI / Arch distro
  • It can run headless, recording GNUplot and statistic data only


  1. Trevor Chandler


    Are you still updating the software?

    If so, are you open to some paid support to help me get setup and understand properly how to configure, what equipment works best and find a proper location to use this against in USA.

  2. alec alden

    Very new to this. Have made a DIY aerial and want to track meteors via Graves. I have purchased a NESDR SMArt v4 SDR and hope to use Echoes to capture and display results. Grateful if someone can give me a step by step guide on how to get this running on my laptop running Windows 10.
    PS I am not anything approaching an expert on PCs and software, so a simple explanation would be welcome.
    Thanks Al

  3. Alastair Grant

    Does Echoes work with the Funcube Pro+ dongle? (under Windows 10)
    I have downloaded Echoes and it doesn’t see the Funcube

  4. Danie

    Good day
    I am using a i7 and Win7 64bit, when I run Echoes I get a error that the PLL is not locked. I am using a 820T2 and a
    NEW GEN RTL2832 with the 828 tuner. Both dongles gives me the same error, then I can use any other SDR software and both dongles work fine.
    Any one that can help me.


    • giuseppe massimo bertani

      Hi Danie,

      Echoes uses librtlsdr to interface the dongle and that message is produced by that .

      I always see that message when I start my program but it still works despite that. Maybe your don’t?

    • giuseppe massimo bertani

      I just tried now, this is what I get when I start Echoes, in the console window:

      echoes(17:29:37)Info: Main thread:0x54b36e0 Reinitializing radio…
      echoes(17:29:37)Info: Main thread:0x54b36e0 Found 1 device(s):
      echoes(17:29:37)Info: Main thread:0x54b36e0 “0: Realtek RTL2838UHIDIR SN: 00000001”
      echoes(17:29:37)Info: Main thread:0x54b36e0

      echoes(17:29:37)Info: Main thread:0x54b36e0 Opening device “0: Realtek RTL2838UHIDIR SN: 00000001” :
      echoes(17:29:37)Info: Main thread:0x54b36e0 Generic RTL2832U OEM
      Found Rafael Micro R820T tuner
      echoes(17:29:37)Info: Main thread:0x54b36e0 Opening successful.
      echoes(17:29:37)Info: Main thread:0x54b36e0 AGC turned off.
      Exact sample rate is: 250000.000414 Hz
      [R82XX] PLL not locked! <===========
      echoes(17:29:37)Info: Main thread:0x54b36e0 Sample rate set to 250000 Hz
      echoes(17:29:37)Info: Main thread:0x54b36e0 FFT flags: 64
      echoes(17:29:37)Info: Main thread:0x54b36e0 Window set to RECTANGLE

      so, if you see the program not working, it should be caused by something other, the "PLL not Locked" message is distracting you from finding the real problem.


      • Anonymous

        Hi Giuseppe
        This is all I get in the console window.

        Log level: 4Found Rafael Micro R828D tuner
        [R82XX] PLL not locked!


        • Grant Martin

          I get the same thing (PLL not locked) for a “R820T” Tuner. Is this a fatal error or just a nuisance not affecting desired functionality/operation?

          Thanks much – Grant

  5. Luc Boulard

    Issues on startup. I’m using Windows7, I7 8 core, 32GB Ram, SSD 480GB. I have issues when I start up Echoes from a saved config file for my frequency. Everything seems to be OK, real time graph, power graph and water fall but its deaf. I’m using a signal generator to check for a received signal. After the buffer time its still not there. If I load the default settings and change them all to what I need and overwrite my setting file then it works most of the time. I also make sure that collection dates are correct. If I check the hardware using SDR# its working. I’m using the R820T original and now also V3. Great program! I’ve learned a lot. Thanks.

    • Anonymous

      Thanks Luc,
      could you explain if you load the .rts file by the means of “open” button or directly, by passing its pathname on the command line?


    • Luc Boulard

      Sorry about the long delay. I start the program and “open” the .rts file using the program. I found a post that mentions a quirk in the program. Just click on +10KHz then -10KHz to get back to the same frequency and it works fine. Verified. That works every time.


  6. Dean Moore

    If anyone else is interested I have compiled qt5 for Raspberry pi which I finally got working on my pi 2.

    worked for me and I hope it solves a few frustrations for others. This took 4 hours or so to fully compile on my i7 laptop so would have taken long long time on the pi itself

    • giuseppe massimo bertani

      Well, i guess you mean for Raspbian, since I successfully ran the app on PI2 under Arch last spring. I’ve chosen Arch since it was the unique distro at that time that included QT5 and QT5charts. But ok, if you found a way to make it run under Raspbian, I’ll post your link on Echoes discussion forum and its Facebook page.

  7. Giuseppe Massimo Bertani

    Hi Max,

    I introduced the periodic mode because it’s the simplest and dumbest way to take screenshots. Simplest because it does not need to set signal thresholds (automatic mode) and dumbest because in this way you record a big amount of data that must be manually selected afterwards. This is also a way to learn about how to set the thresholds for automatic mode.
    The “shot x sec after peaks” control (manual fig.8) does exactly what you’re thinking. The best value should be equal to the time coverage of the waterfall minus 1..2.
    The time coverage depends on the “time interval” control (see manual fig.7). Increasing this value, the waterfall slows down.
    Don’t take in count the “shot duration” control, because it is not about screenshots but about the plot data files.

    Thanks for your feedback.


  8. Giuseppe Massimo Bertani

    Hi Max,
    I introduced the periodic mode because it’s the simplest and dumbest way to take screenshots. Simplest because it does not need to set signal thresholds (automatic mode) and dumbest because in this way you record a big amount of data that must be manually selected afterwards. This is also a way to get an idea about how to set the thresholds for automatic mode.
    So, the delay you mean – “shot x secs after peaks” (see manual 6.3.4) – must be exactly what you’re asking for. Its best value is equal to the total waterfall coverage in seconds, minus 1..2. Notice that you can increase the refresh interval (6.3.3) to make the waterfall browsing slower.
    Remember, the “shot duration” is meaningful only when you record plot files, not screenshots. If you don’t plan to use GNUplot, forget about it.
    Thanks for your feedback.
    BTW. in future, it’s better mail me directly since I get no notifications if someone writes a comment here. Today I’ve seen your post and the post above almost casually, since I didn’t know yet about the article 🙂

  9. Anonymous

    I am a newbie with SDR, so not sure I fully understand how this ECHOES works.
    Does it mean that it only receives reflected waves from GRAVE radar that transmits the waves?
    So it receives the waves at the same frequency as the GRAVE radar transmits?
    Thank you for for explanation

    • Giuseppe Massimo Bertani

      no no, Echoes can be tuned on any frequency supported by your dongle, it’s not GRAVES-centric. The examples in the manual use the GRAVES because in Europe it’s the best source of radar signals for meteor scattering purposes, since it works 24h (except in maintenance stops).
      You should find something similar source located at about 1000…3000 km from your site (looking at the hour you wrote your message, it seems you’re somewhere in America) it could be also an analog TV station – if they still exist there – working in VHF bands I..III . Some says that frequencies below 80MHz give the best results, but I only heard about, never checked.
      If you contact a radio-amateur club I think they can give you much more help in setting up your station. There is also much material available online.
      Thanks for you feedback

  10. Max

    Regarding the 3 operating modes, i don’t think the periodic one is usable because reflecttions can last from less than 1 sec to more than 20sec but most of them are about 1 sec. only. I would like to understand what is the delay in automatic mode before it starts recording to make sure that very short reflections are not cut significantly at the beginning. However the automatic mode is interesting for particular times of the year with high number of reflections most of them lasting over 2 sec. like the Perseids in August

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