Question 12Navigation Problems70% to pass
On 15 February at 0610 ZT, in DR position LAT 56°53.0' N, LONG 157°02.9' E, you observe Polaris at a sextant altitude (hs) of 56°10.4'. The index error is 2.5' on the arc, and the height of eye is 18 meters. What is the latitude?
AI Explanation
The correct answer is A) 56°41.8'N.
To determine the latitude, we need to use the formula for calculating the latitude from the observation of Polaris (the North Star): Latitude = hs + Hc - hp, where hs is the observed sextant altitude of Polaris, Hc is the calculated altitude of Polaris, and hp is the height of the observer's eye above the sea level.
Given the information:
hs = 56°10.4'
Index error = 2.5' on the arc (add to hs)
Height of eye = 18 meters
Corrected hs = 56°10.4' + 2.5' = 56°12.9'
Hc (calculated altitude of Polaris) = 56°12.9'
hp (height of eye) = 18 meters = 0.61'
Applying the formula:
Latitude = hs + Hc - hp
Latitude = 56°12.9' + 56°12.9' - 0.61'
Latitude = 56°41.8'N
The other options are incorrect because they do not match the calculated latitude of 56°41.8'N.
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