Phase distortion due to airflow over a hemispherical laser turret

Resource Information

The work Phase distortion due to airflow over a hemispherical laser turret represents a distinct intellectual or artistic creation found in Internet Archive - Open Library. This resource is a combination of several types including: Work, Language Material, Books.

Label

Phase distortion due to airflow over a hemispherical laser turret

Statement of responsibility

by A.E. Fuhs and S.E. Fuhs

Creator

• Fuhs, Allen E

Contributor

• Naval Postgraduate School (U.S.)
• Huhs, Susan E

Subject

• Guided missiles
• Aerodynamics
• Lasers

Language

eng

Summary

Compressible flow over a laser turret creates a phase distortion. To gain insight to this problem a model of a hemispherical turret is developed. The flow field is obtained using a second order solution based on Janzen-Rayleigh expansion for the compressible potential flow equation. Contours of constant phase distortion were calculated; results at the critical Mach number are presented and discussed. It was found that the distortion at 0 degree elevation angle was equivalent to a positive lens whereas at 90 degrees the distortion is similar to a negative lens. At 45 degrees the main effect is beam tilting into the wind. For a ratio of beam radius to turret radius equal to 0.5, the focal length at beam elevation angle of 0 degrees is 16.5km. At beam elevation of 54 degrees the beam tilt was found to be 26.5 microradians. Cruise missiles with intercontinental ranges may use celestial navigation which requires precise measurement of angular location of stars. A distorted lens created by the ambient flow field causes an error in measurement. Knowledge of the external aerodynamics is important

Cataloging source

AD#

Government publication

federal national government publication

Illustrations

illustrations

Index

no index present

Literary form

non fiction

Nature of contents

• dictionaries
• bibliography
• technical reports

Type of report

Technical report; 1976.