Difference between revisions of "SextantNavigation"
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* Consult a celestial table to calculate the latitude | * Consult a celestial table to calculate the latitude | ||
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To determine longitude: | To determine longitude: | ||
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Each difference of 4 minutes = 1 degree longitude | Each difference of 4 minutes = 1 degree longitude | ||
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| + | == References == | ||
[[Category:NavigatingOperations]] | [[Category:NavigatingOperations]] | ||
Revision as of 19:53, 15 October 2015
Contents
In the event of an emergency when you lose your navigational electronics it would be useful to know how to navigate using a sextant. The simplest calculation is when you take a sun shot at local apparent noon (LAN).[1]
Tools
- Sextant
- Mechanical clock set to Greenwich Mean Time (GMT)
- Mechanical clock set to local time
- Celestial Sight Reduction Tables for Marine Navigation tables
Sun Shot at Local Apparent Noon
Latitude
To determine latitude:
- Point the sextant at the horizon
- Look through the tekescope
- Adjust the index mirror with the index bar until the Sun aligns with the horizon
- Read the angle from the arc
- Note the exact time
- Consult a celestial table to calculate the latitude
Longitude
To determine longitude:
- Note the precise time of noon GMT
- Know the local noon time
- If local noon is before GMT noon you asre on eastern logitutde
- If local noon is after GMT noon you asre on western logitutde
Each difference of 4 minutes = 1 degree longitude
