NavList:

There are quite a few different bearings involved when setting Kollsman Periscopes for celestial shots as well as processing the results with a Polhemus Celestial Computer. To mention a few:

Zn - true bearing to celestial object, clockwise, 0-360 degrees from North

Zn RB - bearing to celestial object, clockwise, 0-360 degrees, from plane's lubber line

Tr - true track of plane, 0-360 degrees from North

Zn-Tr  Polhemus Celestial Computer convention, smallest angle between body's Zn and track of plane 0-90 degrees measured from nose/tail of plane to celestial body either left or right side of plane. Mostly used for Coriolis computation.

But this one confuses me...

SRB Sextant Relative Bearing? It appears to be the bearing to celestial object based on luber line of the plane. I believe it is used to preset the body's Zn relative to the luber line of the plane and is the one that is visible in the Kollsman Periscope viewer when aligning the bubble. The Kollsman bearing ring, in the mount, I believe is set so that 0 degrees is aligned with the plane's lubber line. The scale could be 0-180 left/right degrees. I don't know. Perhaps a Kollsman user could say.

Popko