CwDeepDecoder appended evicted samples with a bare bounds check:
for (v in overflow) {
if (archiveSize < archiveBuffer.size) archiveBuffer[archiveSize++] = v
}
if (archiveSize >= ARCHIVE_THRESHOLD) { flush() }
Once archiveBuffer (64000 samples / 20 s) filled up mid-batch the remaining
samples were silently discarded, because the flush only ran after the loop.
Worst measured case: 47999 samples already accumulated (just under the 48000
flush threshold, so no flush) plus a 64000-sample overflow batch means 111999
samples pushed into a 64000 buffer -> 47999 dropped, i.e. 15 s of audio missing
from the permanently archived CW history.
Now the buffer is flushed as soon as it is full and before appending, so every
sample reaches archiveDecode. Simulation over five batch patterns: dropped
count goes 47999 -> 0 for the worst case and all 111999 samples are archived.
Bounds: single append() can evict at most capacity samples, so drainOverflow()
returns at most 64000 - archiveBuffer never needs to grow.
Look4Sat: Satellite tracker
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.





