mckero 066fafbb81 fix(data): use Mutex to queue calculatePasses, not drop calls
The previous guard (if (_isCalculating.value) return) silently dropped
concurrent calls. Every call carries filter settings the user just applied,
so a dropped one left the list showing results for the previous filter:

  User clicks 'Apply' with elevation>=5
  -> UI updates to show elevation>=5
  -> calculatePasses(elevation>=5) called
  -> but if _isCalculating=true, return immediately
  -> list still shows elevation>=30 results

The guard window is wide: delay(1000) + real calculation time (hundreds
of ms to seconds), exactly when the progress indicator spins and users
naturally interact again.

Mutex serializes calls instead: the second one queues and eventually runs
with its own parameters. This also fixes the original concurrency issue
(duplicate parallel calculations) and adds finally {} so a thrown exception
cannot leave isCalculating stuck at true (frozen progress indicator).

Reverts the regression introduced in the previous attempt to add concurrency
protection.
2026-08-14 13:07:53 +00:00

Look4Sat: Satellite tracker

Look4Sat CI

Get it on Google Play Get it on F-Droid

Radio satellite tracker and pass predictor for Android, inspired by Gpredict

Track satellite passes with ease!

Thanks to Celestrak and SatNOGS you have access to over 9000 active satellites.
You can search the entire database by NORAD Catalog Number or the satellite's name.

Orbital positions and passes are calculated relative to your location.
To get reliable data make sure to set the station position via the app Settings.

The application is built using Kotlin, Coroutines, Jetpack Compose and Navigation.
It is now and always will be completely ad-free and open-source.

Main features:

  • Predicting satellite positions and passes for up to 10 days
  • 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 the map
  • Custom TLE satellite data import is available via Three Line Element .txt files
  • Offline first: calculations are made offline. Weekly TLE data update is recommended.

License

The Look4Sat application code is licensed under the GNU General Public License v3.0.

The CW decoder in feature/cw bundles the DeepCW neural decoding model, licensed under the GNU Affero General Public License v3.0 only (AGPL-3.0-only). Because the combined work incorporates an AGPL-3.0 component, the combined work is distributed under the GNU Affero General Public License v3.0 — GPL-3.0 Section 13 permits the combination, and AGPL-3.0 Section 13 applies to the combined work as a whole. Model provenance and attribution are documented in feature/cw/licenses/NOTICE.md; the original GPL-3.0 text is preserved at feature/cw/licenses/Look4Sat-GPL-3.0.txt. The CW model runs locally on-device and does not provide services over a network.

Star History

Star History Chart
S
Description
Satellite tracker and pass predictor for Android, inspired by Gpredict
https://play.google.com/store/apps/details?id=com.rtbishop.look4sat
Readme AGPL-3.0
55 MiB
0 Stars 1 Watchers 0 Forks
v4.6.2
Latest
2026-08-27 15:47:20 +00:00
Languages
Kotlin 100%