PRECISE DETERMINATION OF ATMOSPHERIC DISPERSION WITH APPLICATIONS TO LONG-PATH INTERFEROMETRY
Abstract
The accuracy with which it is feasible by purely interferometric means to separate information about geometric path differences was investigated from information about the optical density of the atmosphere. A precision refractometer was designed and measurements were made of the relative dispersions of air, water vapor, nitrogen, and oxygen in the region from 3800 to 6400 Angstroms. The results for air show a high degree of invariance under changes in pressure and reveal a slight deviation from the relative dispersion given by Edlen's formula. Results for nitrogen and oxygen conform well with the ClausiusMossotti relation as applied to air. An analysis was made of the errors which would affect interferometric comparisons of long paths through an uncontrolled atmosphere. Results showed that humidity variations are the most serious and that variations of 1% in the relative humidity at 15 C would cause errors of approximately 2 parts in 10 to the eighth power. The feasibility of obtaining interference at large distances under controlled conditions was investigated. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1961
- Accession Number
- AD0264709
Entities
People
- Kent E. Erickson
Organizations
- Johns Hopkins University