Difference between revisions of "SextantNavigation"
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* Celestial [http://msi.nga.mil/NGAPortal/MSI.portal?_nfpb=true&_pageLabel=msi_portal_page_62&pubCode=0013 Sight Reduction Tables for Marine Navigation] tables | * Celestial [http://msi.nga.mil/NGAPortal/MSI.portal?_nfpb=true&_pageLabel=msi_portal_page_62&pubCode=0013 Sight Reduction Tables for Marine Navigation] tables | ||
| − | == Latitude == | + | == Sun Shot at Local Apparent Noon == |
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| + | === Latitude === | ||
To determine latitude: | To determine latitude: | ||
Revision as of 19:52, 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
