Search Results for: GREENWICH HOUR ANGLE

What are 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. In the diagram below: LHA is the angle BNU on the Earth’s surface which corresponds to the angle ZPX … Continue reading

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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. In the diagram below: LHA is the angle BNU on the Earth’s surface which corresponds to the angle … Continue reading

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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

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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. As the above links demonstrate, there are several methods of employing … Continue reading

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Local Hour Angle

Local Hour Angle (LHA).  In astro navigation, we need to know the position of a celestial body relative to our own position. In the diagram below, LHA is the angle BNU on the Earth’s surface which corresponds to the angle ZPX in … Continue reading

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Exercise 4 – Local Hour Angle.

This post continues the series of navigation related exercises which were requested by navigation course and nautical college teachers.  When the post expires, its contents will be included under the menu heading ‘Navigation Exercises’ on the home page. Local Hour … Continue reading

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The Importance Of Morning And Evening Star Sights

Part 1 – Checking to see which stars and planets will be above the observer’s horizon during Nautical Twilight on a certain day. By Jack Case Introduction. The Astronomical Position Line.  A position line is a line drawn on a … Continue reading

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THE IMPORTANCE OF MORNING AND EVENING STAR SIGHTS

Part 1 – Checking to see which stars and planets will be above the observer’s horizon during Nautical Twilight on a certain day. By Jack Case INTRODUCTION The Astronomical Position Line.  A position line is a line drawn on a … Continue reading

Translating A Celestial Position Into A Geographical Position.

This follows the previous post which discussed the Celestial Co-ordinate System. If we wish to use a celestial body’s position in the celestial sphere to help us to navigate on the Earth’s surface, we must be able to translate that … Continue reading

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Translating a Celestial Position Into a Geographical Position.

This follows the previous post which discussed the Celestial Co-ordinate System. If we wish to use a celestial body’s position in the celestial sphere to help us to navigate on the Earth’s surface, we must be able to translate that … Continue reading