Accession Number:

ADA517293

Title:

The Aggregate Behavior of Branch Points - Branch Point Density as a Characteristic of an Atmospheric Turbulence Simulator (postprint)

Descriptive Note:

Conference paper (postprint)

Corporate Author:

AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE

Report Date:

2009-06-01

Pagination or Media Count:

14.0

Abstract:

The atmospheric turbulence simulator used in testing in the atmospheric simulation and adaptive-optic laboratory test-bed at Starfire Optical Range is configured based on three characteristics Frieds parameter, the Rytov number and the Greenwood Frequency. All three may be estimated from open loop data as a means of verifying the simulated turbulence conditions for a given test configuration. However, unlike Frieds parameter and the Greenwood Frequency the Rytov number isnt directly calculated. Instead the scintillation index is estimated from intensity measurements. At low Rytov values, 0.3-0.4, this measurement can approximate the Rytov number however beyond a Rytov of 0.4 this parameter becomes saturated. Branch Points begin to appear after the Rytov value exceeds 0.1. In this work the behavior of branch point density is examined to determine its viability as another parameter for calibration our turbulence simulator.

Subject Categories:

  • Atmospheric Physics
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE