A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Gary LaPook
Date: 2016 Nov 23, 23:20 -0800
I am attaching several photos of my Polhemus showing some additional markings I placed on it.
One can calculated the coriolis corrctions for each individual sight instead of moving the AP or the final fix. On the front of the Polhemus I placed a "C+" mark on the left edge and a "C-" mark on the right edge which shows the sign of the coriolis correction in the northern hemisphere, any body to the left of the track requires adding the coriolis correction the Hp and must be subtracted if the body is on the right.
On the plotting side I placed a "C ^" at the 90 degree left and is used for moving the AP or fix when using that method for making the coriolis correction. Simply turn the overlay until the track is at the 90 degree left point and then move the fix up the number of miles for the correction.
At the bottom on the plotting side I placed a "S" index for use in the southern hemisphere, use it for azimuths.
Near the center I placed two scales, a horizontal scale to the left corresponding to the latitude of the plane and the vertical scale for the ground speed of the plane. These scales can be used as an alternative way to account for the MOB and MOO adjustments without using the face of the polhemus.