User Guide (EN)

The Via Solis application calculates the position of the Sun (azimuth and elevation) with high accuracy and, based on these calculations, allows you to determine your geographic orientation using interactive maps and a solar compass.  

Upon launching the app, after the splash screen, the home page appears:

The map displays the user's position (person icon), determined by GPS or manual input of geographic coordinates, along with the position of the Sun.  

• Button 1: Allows you to select the map display mode (dark or light), regardless of the display mode set on your device. By default, the app matches the device's system mode.  

• Button 2: Centers the person icon on the screen.  

• Button 3: Activates the solar compass. This is a "geographic compass" that enables you to determine orientation relative to the cardinal directions (North, South, East, West).  

• Banner 4: Displays useful real-time information:  

  • MODE: Indicates whether the user's position is established via GPS (GPS) or manual coordinate entry (MANUAL).  

  • Status: Indicates whether the app has internet access (ONLINE) or not (OFFLINE).  

  • Lat: Shows the current latitude of the user's position.  

  • Lon: Shows the current longitude of the user's position.  

  • Azimuth: Displays the real-time calculated solar azimuth in degrees.  

  • Elevation: Displays the real-time calculated solar elevation/height in degrees.  

If reading the data on Banner 4 is difficult due to screen size or bright ambient light, you can enlarge it by tapping on it.  

Due to atmospheric conditions and obstructions such as buildings or mountains, the GPS location may not correspond to your actual position. If you notice a position error, you can correct it using the drag-and-drop function on the person icon: press and hold the icon until it turns red, then drag it to the correct location on the map.  

If you cannot determine orientation by combining the Sun's position with the map, you can use the solar compass.

USING THE SOLAR COMPASS

Tapping the “OPEN COMPASS” button opens the calibration page. To calibrate, point the arrow toward the Sun while holding the device horizontally. Use the built-in bubble level to position the device correctly: the device is horizontal only when the crosshair is centered in the target, at which point the OK button turns yellow and clickable.  

Once the OK button turns yellow and you are satisfied with pointing the arrow at the Sun, the compass is configured, and tapping OK activates it.  

The top-right menu (5) allows you to select the measurement mode (7) for the direction indicated by the pointer (6):  

1. Navigation Mode (0–360°): Based on the international navigation convention: North = 0°, East = 90°, South = 180°, West = 270°.  

2. Solar Geometry Mode (South 0°): Based on the international solar geometry convention: North = ±180°, East = -90°, South = 0°, West = +90°.  

WARNINGS AND LIMITATIONS

Although the solar azimuth is calculated as accurately as possible, solar compass measurements depend on several physical factors and device sensors:  

1. GPS Error: The GPS may indicate a position slightly different from your actual location. If you notice an error on the map, use drag-and-drop to move the icon to your true position and eliminate this error.  

2. Pointing Error: Pointing the arrow precisely at the Sun can be challenging, which may introduce uncertainty into the compass configuration and measurements.  

3. Leveling Error: To facilitate centering the crosshair in the target, a one-degree tolerance is built into the level.  

4. Accelerometer Error: The accelerometer requires periodic calibration. Uncalibrated accelerometers may introduce errors during setup. Furthermore, software calculations keep the compass bezel horizontal when rotating the device; steep tilts can cause jittering of the bezel. Vibration notifications can also negatively affect accelerometer accuracy, so disabling device vibration during use is recommended.  

5. Gyroscope Error: Software management of the gyroscope can accumulate mathematical errors over time, causing bezel jitter or slow drift. Periodic recalibration is recommended.  

If you notice bezel jitter after configuring the compass, repeat the calibration process.  

Map tiles are stored in the device's persistent memory to allow offline use. However, this can gradually fill up device storage. It is recommended to periodically check the storage space used by the app's data.