A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Greg Rudzinski
Date: 2018 Jun 8, 14:06 -0700
If using the Bris sextant then it is required to calibrate the upper limb, lower limb, and center Sun individually since the reflected image is often not symmetrical.
When performing sight reduction you will need Ho to comparem to Hc. Hs is corrected for index error ( sextant), dip, refraction, and semi diameter to get Ho. When calibrating the Bris it will be necessary to reverse the signs of all the corrections to apply to Hc from calculator or table to get Hs calibration.
When precalculating a time sight use Ho, latitude, and declination in the formula to get LHA (t).