This sketch is based off of the bridge shot with the captain's chair and the group shot in front of the viewer:
Before anyone says it, yes this is about 75% assumption. I assume the bridge is perfectly symmetrical, for example. I assume there's nothing special just off camera. The proportions, size, and positions are all very loose guesstimations. I assume the nav/helm consol is just a bigger version of that podium since it's not in any shot.
EDIT: This is also slightly oval: 20ft radius on the fwd axis, 22ft radius on the prt/stbd axis.
So...what'd you think?