mckero
d5230b3bc6
A full-domain round-trip probe found three related boundary bugs.
1. Exact positive limits wrapped the square/subsquare terms to zero
positionToQth clamped only the A-R field index. At +90 latitude / +180
longitude the field saturated at R, but all later terms used modulo and wrapped
to square 0 / subsquare a:
(90, 180) -> RR00aa00 -> (80.002083, 160.004167)
error: -9.998 deg latitude, -19.996 deg longitude
The existing test incorrectly asserted RR00aa00 and had therefore fossilised
the defect. Clamp shifted coordinates just inside the half-open upper bound so
the limits land in the final cell RR99xx99.
2. isValidPosition allowed longitude through +360
Maidenhead covers -180..180, but 181..360 was accepted and produced plausible
locators that decoded 20-200 degrees away:
lon 181 -> decoded 161.004167 (error -19.996)
lon 270 -> decoded 170.004167 (error -99.996)
lon 360 -> decoded 160.004167 (error -199.996)
Restrict the converter contract to -180..180.
3. Locator validation allowed S-X as field letters
The first pair has 18 fields A-R, while only the later subsquare pairs use
A-X. The shared [A-X]{2} regex accepted SS00aa / XX99xx and decoded them past
the poles (up to lat 149.98, lon 299.96). Use A-R for the field pair.
The SettingsRepo caller had a separate wrapping bug that masked part of this:
it mapped longitude>180 by subtracting 180 (270 -> +90, wrong hemisphere)
instead of modulo 360 (270 -> -90). Fix that at the writer too.
Verification:
- standalone JVM sweep: 519,841 points, old code had 1,441 large-error points
with max drift 9.997917 deg lat / 19.995833 deg lon
- new Kotlin regression sweep requires every 8-char round trip <=0.01 deg
- QthConverterTest BUILD SUCCESSFUL
- full :core:domain:test + :core:data:compileReleaseKotlin BUILD SUCCESSFUL
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.