Finding Latitude by taking noon sun sights:

Oval: Earth




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When the Sun is at real noon, (at the highest point on the observer's meridian) , it is either due North or due South to the observer. The observer's line of position is then due East or due West. Since East-West line is parallel to the latitude, it is possible to find the latitude of the observer by means of right triangle.  

The principle is identical to finding latitude by the Polaris. The sun's altitude from the position of the observer is equal to the latitude of the observer. Finding the sun's altitude with a sextant may be more difficult because of the great light intensity of the sun. Therefore, the sextant may have to be modify a little by putting a photograph negative film in front of the index mirror of the sextant to reduce the light intensity.


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