YAMAKAGE - WatchApp

YAMAKAGE - Terrain-Aware Sunset & Sunrise Prediction ■Overview & Key Features Darkness falls faster in mountains than standard sunset times suggest. YAMAKAGE is a smartwatch app that calculates and visualizes "true" sunrise, sunset, moonrise, and moonset times by analyzing surrounding terrain. By scanning elevation data up to 30 km away, it compares celestial trajectories with mountain heights to predict exactly when the sun or moon will be hidden or revealed, offering an intuitive graphical understanding of your environment. Displayed Data & Views After pressing "START" to run the calculation, you can swipe to explore three distinct screens: ・Panorama View: Overlays obstacles (like mountains) and their elevation angles in your watch's current heading alongside the sun/moon trajectory. ・SkyPlot: A 360-degree overhead circular graph displaying surrounding elevation profiles and celestial paths. ・Radar View: A top-down radar showing real-time distances (in km) to obstacles and open directions. ・Details: Displays terrain-adjusted times and obstacle elevation angles based on your heading. ■Mechanism & Privacy To minimize battery consumption and processing load, YAMAKAGE delegates complex calculations to a cloud server: ・The app sends your current GPS coordinates to the server. ・The server analyzes global terrain data within a 30 km radius. ・It calculates trajectories against the terrain cross-section and returns rendering data to your device. ・Privacy Note: Location data is transmitted solely for calculations using a random temporary hash. No personal data is collected, and locations are instantly discarded after processing. ■Precautions, Disclaimer & Links ・Requirements: Requires a connected smartphone (Garmin Connect Mobile app) and a clear outdoor GPS signal. ・Limitations: Polar regions (e.g., midnight sun) will display as --:--. Ensure good connectivity to avoid communication errors. ・Disclaimer: Times are predictions based on ~38m mesh terrain data. Because weather, trees, and buildings are not accounted for, actual times may vary. Always plan activities with a generous time margin. ■Explore More: ・Data Field Version: Garmin Store https://apps.garmin.com/apps/cbe81d8e-661d-49b0-bc4c-a1fc8ab10d53 ・Source Code: YAMAKAGE is an open-source project. Anyone can view its internals on GitHub. https://github.com/tomopumipumi/yamakage ・Browser Demo: Try it Here https://yamakage-site.pages.dev/