Tag Archives: navigation

Distance to the Horizon

The Pharos Lighthouse.  The Pharos Lighthouse or the Lighthouse of Alexandria as it was also known, was commissioned by Ptolemy Soter the ruler of Egypt and completed during the reign of his son Ptolemy II in about 270BC.  It was … Continue reading

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Declination Table For Survival Use

Sun’s Declination Table constructed for use in survival situations to be used when calculating latitude from the altitude of the midday sun. Provided by Astro Navigation Demystified (www.astronavigationdemystified.com) The following table shows the mean values of the declination of the … Continue reading

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How To Make A Mini-Clinometer For Survival Use

A clinometer is a simple device that can be used to measure the altitude of an object. Despite its simplicity, a clinometer provides a level of accuracy sufficient to measure angles to the nearest degree.  A ‘mini-clinometer’ as shown below, … Continue reading

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Could the Global Positioning System Fail?

Quite apart from the local risks of defective equipment, battery failure, generator failure and short-circuits to electronic navigation equipment caused by flooding, there is a very real global risk that the GPS could be destroyed. During periods of increased solar … Continue reading

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Latitude from the Midday Sun

Finding Your Latititude From The Midday Sun. The following diagrams will help to explain how the latitude can be calculated from the Sun’s midday altitude and its declination.  In the following diagram , NOS  represents the horizon and O represents … Continue reading

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