# Tag Archives: mathematics of astro navigation

## Making An Ocean Plotting Sheet

Ocean plotting sheets are nautical charts designed for use at specific latitudes. They are used for ocean navigation where features such as shorelines, water depths and local tidal information are of no importance. Plotting sheets are particularly useful for plotting … Continue reading

## Stars For All Seasons Part 7 – Spring Stars in the Northern Hemisphere.

Spring Stars in the Northern Hemisphere. Spring is just around the corner and when the winter constellations begin to make their exits to the west, we will find Boötes, Leo, Cancer, Hydra and Virgo lurking in the wings ready to … Continue reading

## Accuracy of Sight Reduction Methods.

In my recent article ‘Why Astro‘, I highlighted the risks in using the GPS.  Since writing that article, I am frequently asked “if astro / celestial navigation is to be used, which of the many systems is the best”.  Sight … Continue reading

## Astro Navigation In A Nutshell Part 2.

Part 2 – The Intercept Method Link:  Astro Navigation In A Nutshell Part One Astro Navigation in a Nutshell Part 3 Astro Navigation in a Nutshell Part 4 Suppose we are in a yacht and we measure the altitude of … Continue reading

## Calculating Azimuth And Altitude At The Assumed Position By Spherical Trigonometry.

There are several ways of calculating the azimuth and altitude at the assumed position; these include the use of sight reduction methods and software solutions. However, the traditional method is by the use of spherical trigonometry which is demonstrated below. … Continue reading

## Survival – Calculating Altitude Without An Angle Measuring Instrument

Links:  Astro Navigation in a survival situation.    Latitude from the midday Sun.    Find your longitude.     Calculating declination.    Declination table.     Trig table.    Revise trigonometry  Revise Spherical Trigonometry As the above links demonstrate, there are several methods of employing astro navigation … Continue reading

## The Rhumb Line

If a ship were to steer a steady course, that is one on which her heading remains constant, her track would cut all meridians at the same angle, as the following diagram shows.  Such a line on the Earth’s surface … Continue reading

## Astro Navigation – What is it and why do we need it?

Astro-navigation (or celestial navigation as it is also known) is a fascinating subject that encompasses many areas of knowledge including geography, astronomy, history and mathematics.  As you unravel the principles and techniques upon which navigation is based, you will be … Continue reading

## 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

## Revise Pythagoras’ Theorem

If after reading some of my other posts, you feel you are a bit rusty on Pythagoras’ Theorem, here is a quick brush up for you.  We can see in the diagram below that, in the triangle ABC, if a … Continue reading