Can you determine latitude by measuring the sun's angle?

Understanding Solar Noon Navigation

Solar noon navigation is a technique used to determine latitude by measuring the sun’s angle at noon. This method relies on the Earth’s tilt and rotation to estimate the sun’s declination. Declination is the angle between the sun’s apparent position in the sky and the celestial equator, which varies throughout the year.

Measuring the Sun’s Angle

To measure the sun’s angle, you’ll need to use a sextant or an equivalent device. Hold the device level and point it at the sun at noon. The angle between the sun and the horizon is called the altitude angle. Record this angle and use a declination chart to determine the sun’s declination for the current date. Then, use a formula to calculate your latitude.

Calculating Latitude

The formula to calculate latitude using solar noon navigation is: latitude = (90 - declination) * (altitude angle / 90). This formula is based on the assumption that the sun is at its highest point in the sky at noon. By plugging in the declination and altitude angle, you can determine your latitude with reasonable accuracy. Keep in mind that this method requires a clear view of the sun and an accurate device to measure the angle.