Measurement of the Atmospheric Phase Coherence Length, r sub o.
Abstract
This report provides a method of measuring the atmospheric phase coherence length, r sub o, (also referred to as the diffraction limited aperture of the atmosphere), directly by using a telescope, a few optical instruments, a photomultiplier tube, a spinning reticle wheel, an A to D converter and a computer. Chapter 1 explains the meaning of r sub o and how it limits the performance of optical equipment viewing objects through the atmosphere. The second chapter is an explanation of the modulation transfer function of the atmosphere, and how it can be obtained using a telescope, collimators and a spinning reticle wheel. Chapter 3 describes how analog signal which is produced by the photomultiplier is digitized into an 8 bit digital signal by a device known as a datagrabber, and then fed into the computer. Chapter 4 describes how the data is used to calculate r sub o. The final chapter explains the problems encountered and suggestions to improve the experiment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1986
- Accession Number
- ADA178468
Entities
People
- Gary D. Wilkins
Organizations
- Rome Laboratory