Experiences with the U.S. Naval Observatory Glass Circles

Abstract

It has been found in the course of U.S. Naval Observatory experience with the circles used to determine the declination position angle of a meridian circle that the quality of glass circle division lines is superior to those of conventional metal circles. Such quality is important when photoelectric scanning devices are used to read the circle. Analyses of the diameter corrections obtained with a number of the glass circles are given, and a method is introduced which allows the monitoring of circle stability without taking an entire set of diameter corrections.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1982
Accession Number
ADA575150

Entities

People

  • B. L. Klock
  • T. J. Rafferty

Organizations

  • United States Naval Observatory

Tags

DTIC Thesaurus Topics

  • Astrophysics
  • Buildings And Structures
  • Contracts
  • Corporations
  • Diameters
  • Harmonic Analysis
  • Materials
  • Microscopes
  • Monitoring
  • Observation
  • Observatories
  • Periodic Variations
  • Photographs
  • Scanners
  • Scanning
  • Standards
  • Visual Inspection

Readers

  • Geodesy