On 16 February your 1845 ZT DR position is LAT 25°50.5' N, LONG 46°24.0' W. At that time you observe Polaris with a sextant altitude (hs) of 26°25.5'. The chronometer time of the sight is 09h 47m 30s and the chronometer error is 02m 16s fast. The index error is 2.5' off the arc, and the height of eye is 55.0 feet. What is your latitude by Polaris?

Question

On 16 February your 1845 ZT DR position is LAT 25&deg;50.5' N, LONG 46&deg;24.0' W. At that time you observe Polaris with a sextant altitude (hs) of 26&deg;25.5'. The chronometer time of the sight is 09h 47m 30s and the chronometer error is 02m 16s fast. The index error is 2.5' off the arc, and the height of eye is 55.0 feet. What is your latitude by Polaris?

Accepted Answer

Option A: 25&deg;38.0'N. Correct the sextant altitude for index error, dip, and refraction to find Ho. Use the Nautical Almanac to determine the LHA of Aries. Apply the Polaris correction tables based on the LHA of Aries to the Ho. This yields the latitude of 25°38.0'N, consistent with standard Polaris observation procedures.