Look4Sat: An Android App for Tracking and Predicting Amateur Radio and Weather Satellite Passes

Thank you to Arty Bishop for submitting news about his recently released Android App called Look4Sat. Look4Sat is a satellite tracker and pass predictor with a focus on amateur radio and weather satellites. The app is free, ad free, and open source on GitHub.  Arty writes that he's programmed this as a learning exercise and notes:

I always wanted to have an offline and not bloated satellite tracker on my phone, as carrying the laptop at all times is kinda not too handy.

The app uses predict4java library under the hood and is written in Kotlin. The TLE files are from Celestrak and the transmitters info is from SatNOGS and once they are  ownloaded the app doesn't need an internet connection.

The app creation and design is hugely inspired by Gpredict which is an absolutely brilliant piece of software. Thank you, Alexandru!

Obviously there is no ads and it's totally free. Hope more people find Look4Sat useful.

The features include:

  • Calculating satellite passes for up to one week (168 hours)
  • Calculating passes for the current or manually entered location
  • Showing the list of currently active and upcoming satellite passes
  • Showing the active pass progress, polar trajectory and transceivers info
  • Showing the satellite positional data, footprint and ground track on a map
  • Offline first: pass prediction is done offline. It's up to you to decide when
    to update the TLE file and the transceivers DB. (Updates once a week are recommended)
Look4Sat Android App Screenshots
Look4Sat Android App Screenshots


  1. Roy

    Lots of missing sats (like AO-91, HuskySat-1, etc.).
    Any chance of using another set of TLEs? Specifically – nasabare.txt from Amsat.org? Otherwise nice software. Including doppler shift calculations would be a cool addition.

  2. Ladislav OK1UNL

    Hmm, me ticked all satellites from list. Is impossible start run of tracking all positions. If me ticked only few from list no problem…
    Phone Huawei Android 9.0pie

    • Arty Bishop

      Hello, Ladislav!
      I can confirm, it’s definitely a bug. Although I’ve been testing the app calculating passes for 240 Starlink satellites (they are not in a release app), I never thought of that as a realistic use case. Having so many satellites selected simply overloads your screen with information and you won’t be able to physically track or listen to all of them at a time because the passes start literally every 30s-1min, the sky is filled with objects. Also not all of the sats have active and publicly listed transceivers which renders them not so useful for radio amateurs.

      Anyhow, I’ll try to fix it, you got me curious on that. I think I know what might be the cause of it. Hopefully I will be able to fix this bug within the next few days. Thank you very much indeed for your feedback!

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