Solar Compass

Carina Labs

About this app

Find True North with Solar Compass – Your Essential Tool for Navigation & Daytime Polar Alignment!

Solar Compass transforms your Android device into an instrument for accurately determining True North using the Sun's predictable path given your location. This app is useful for astrophotographers needing precise daytime setup of equatorial mounts, as well as for anyone requiring an accurate geographic North reference.

Integrated magnetic compasses in smartphones require frequent, often finicky, calibration and are highly susceptible to interference from nearby metallic objects making them unreliable. A standard physical magnetic compass points to Magnetic North, not True North. To find True North, you must know the local magnetic declination and be able to apply this correction. Solar Compass bypasses these issues by relying on the consistent and predictable motion of the Sun.

Step-by-Step Usage (The Shadow Alignment Method):

Grant Location Permission: This is essential for the app to obtain your coordinates for calculation.

Ensure Sunlight: A clear, unobstructed view of the Sun is necessary to cast a sharp, distinct shadow.

Level Your Phone: Place your phone on a stable, flat surface. Use the app's integrated bubble level indicator, carefully adjusting the phone's orientation until the bubble is precisely centered.

Vertical Pointer (Gnomon): Position a thin, straight, and truly vertical object at the exact center of the on-screen compass dial. A dedicated stylus, a thin rod, a pencil held steady, or a simple plumb line (a string with a small weight) works best. The more vertical the pointer, the more accurate the shadow.

Align the Shadow: Observe the shadow cast by your vertical pointer. Carefully and slowly rotate your entire phone (while keeping it perfectly level) until the pointer's shadow aligns exactly and precisely with the Red Line (Shadow Direction marker) displayed on the app's compass dial.
Identify True North: Once the shadow is perfectly aligned with the red line, the "N" marking on the app's compass dial will be pointing directly towards True North (Geographic North).

Daytime Polar Alignment for Astrophotography & Equatorial Mounts: Detailed step-by-step instructions are available directly within the app's menu.

Key Features:

Highly accurate Sun Azimuth & Altitude calculation powered by the Astronomy Engine library.

Determines True North (Geographic North)

Integrated Bubble Level for ensuring precise device orientation, crucial for accuracy.

Automatic and precise location acquisition via device GPS.

Clear, uncluttered compass interface with a distinct Shadow Direction Line (Red Line).

In-app menu with detailed, step-by-step Daytime Polar Alignment instructions tailored for equatorial mount users.

All calculations are performed locally on your device.

Important Considerations:

Solar Compass identifies TRUE NORTH. This will differ from Magnetic North due to local magnetic declination, which varies globally.

The accuracy of the True North determination depends on:

The device being perfectly level (use the in-app bubble level carefully).

The shadow-casting pointer being perfectly vertical.

The precision with which the user aligns the shadow to the on-screen Red Line.

The ACCESS_FINE_LOCATION permission is essential for the app's core functionality, as accurate location is paramount for the calculations.
Sensor data (from Accelerometer and Magnetometer) is used exclusively for the on-screen bubble level feature to aid in device orientation.
Your Privacy is Respected: All location and sensor data are processed locally on your device solely for the app's stated functionality. This data is not stored, shared, or transmitted off your device by the Solar Compass app. Please refer to our Privacy Policy for complete details.

What’s new

Welcome to Solar Compass!
* Find True North accurately using the Sun and your device's GPS.
* Integrated bubble level helps ensure precise phone orientation for best results.
* Includes step-by-step instructions for daytime polar alignment of equatorial telescope mounts.
* Easy-to-use compass interface with a clear shadow direction line.
* Calculates Sun Azimuth & Altitude using the reliable Astronomy Engine.
* We hope Solar Compass becomes your go-to tool for astrophotography setups!