A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Brad Morris
Date: 2016 Feb 2, 18:57 -0500
The +/-2° measuring range, and the fact that the angle is taken between objects 180° apart speaks to a very specific celestial navigation device.
It could be dip meter. The dip of the horizon is normally assumed in celestial navigation. However, the assumed dip can often be wrong, as a function of abnormal refraction.
With a dip meter, one aligns the horizons 180° apart and measures the dip. This accounts for eye height and existing refraction. The measured value is divided by two to obtain the dip to one horizon.
The measured dip is then substituted for assumed dip, yield a more precise reduction of the calculated angle from the observed angle of the sextant.
I have no knowledge of what your device is, only what it 'could be', as the specifics described by you correspond to that detailed herein. This may be just a coincidence.
We in the optics section of the "Wehrmacht Awards" forum are discussing a complex German WWII optic that may be a specialized type of sextant, OR something else. It is designated as Ktm. C/4. All info available, photos, and a video are in this thread, so not yet being familiar with your posting procedures, if you will,permit, I will provide the link to that discussion and move Rome photos here as I am able. Thanks for any help you can provide. http://wehrmacht-awards.com/FORUMS/showthread.php?p=4915266