Tag Archives: celestial navigation training

The Demystified Astro Navigation Course Unit 3 Part 2

Unit 3 Part 2 – Altitude Correction tables for the Sun, Stars and Planets. As shown in the table extract below, corrections for the Sun are divided into two parts to allow for changes in the Sun’s semi-diameter during the … Continue reading

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The Demystified Astro Navigation Course – Unit 3 Part 1

Unit 3  Part 1 – Altitude and Azimuth     The Azimuth is similar to the bearing in that it is the angle between the observer’s meridian and the direction of the celestial body.  However, whereas bearings are measured clockwise from north … Continue reading

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The Demystified Astro Navigation Course Unit 2

Unit 2 – Local Hour Angle and Greenwich Hour Angle  Local Hour Angle (LHA).  In astro navigation, we need to know the position of a celestial body relative to our own position. (The following diagram illustrates the explanations given below). LHA … Continue reading

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The Demystified Astro Navigation Course – Unit 1

Unit 1 Essential Astronomy for Navigators The Celestial Sphere is an imaginary sphere with the Earth located at its centre. We imagine that the ‘celestial bodies’ such as the Sun, Moon, stars and planets are placed on the inner surface … Continue reading

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The Relationship Between Longitude, Latitude and the Nautical Mile.

The Relationship Between Longitude and the Nautical Mile.  The Earth’s equatorial circumference is 21640.6 n.m.  Since the Equator is a great circle, 1o will subtend an arc of:  21640.6 ÷ 360 =  60.113  ≈ 60 n.m. There are 360 meridians of Longitude so … Continue reading

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Calculating the Sun’s Declination in a Survival Situation

In an ideal situation, we could find our latitude by using a satellite navigation system.  If sat-nav is not available, we can use astro navigation to calculate our latitude by the method shown at the following links: Latitude from the … Continue reading

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Planning Star and Planet Observations

I have been asked about using ABC tables to calculate azimuth and altitude when planning star and planet observations.  Unlike the Sun and the Moon which are easily identified, the approximate positions of stars and planets need to be established … Continue reading

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Astro Navigation In A Survival Situation

In a recent survey, the majority of people questioned were surprised to learn that astro navigation can be used in a survival situation.  In the same survey, 60% said that they would use satellite navigation systems to find their way … Continue reading

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Finding Latititude In A Survival Situation.

The  full method of calculating your latitude from the altitude of the Sun can be found at this link.  However, in a survival situation, the following simplified method can be used. Equipment Needed.  A clinometer or other device for measuring angles. … Continue reading

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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

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