photographic zenith tube

'photographic zenith tube' can also refer to...


More Like This

Show all results sharing this subject:

  • Astronomy and Astrophysics


Show Summary Details

Quick Reference

A telescope with its objective lens fixed pointing vertically upwards. Stars are photographed as they pass the zenith, both directly through the telescope and after their light has been reflected from a mercury mirror beneath the objective lens. The PZT is designed to measure the direction of the instantaneous vertical relative to the stars, and hence accurately determine the longitude and latitude of the observatory.

Subjects: Astronomy and Astrophysics.

Reference entries

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.