NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2014 Nov 1, 18:54 -0700
Sam,
No need to be perfect with the preset. Time can be 10 minutes off and still get the Sun into the field of view. I use a phone app to calculate the Hc for my assumed position. The app has an almanac and a chronometer so by pushing the now button an Hc pops up which I double to set the artificial horizon sextant preset. If using 229 / 249 the the nearest degree of latitude, LHA, and declination should get the Sun into the field of view.
Greg Rudzinski
From: Samuel L
Date: 2014 Nov 1, 12:18 -0700
Greg,
Preset Altitude is something we've just begun to experiment with. So far, using an AH, we can see both images of the Sun but not exactly superimposed or Upper Limb or Lower limb touching.
Tell me if this is right or wrong....or the correct way to go about it.
- determine the exact time you want to take the Sun sight and calculate Hc
- preset the Sextant to the calculated Hc (when using an AH multiply Hc times 2 and subtract or add SD depending upon which limb is being observed).
What do you think? What method do you use?
Thanks,
Sam L.
