Accession Number : ADA191006

Title :   Utilization of Dense Packed Planar Acoustic Echosounders to Identify Turbulence Structure in the Lowest Levels of the Atmosphere.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Moxcey, Louis R

PDF Url : ADA191006

Report Date : Dec 1987

Pagination or Media Count : 73

Abstract : Coherent light beams propagating through the atmosphere undergo considerable phase perturbations due to fluctuating temperature structures in the atmosphere. Understanding and measuring these structures on a real-time altitude dependent basis is inherent to successful deployment of ground based lasers and particle beams. One method used to detect these temperature structures is an acoustic profiler, or echosounder. Of immediate interest is the ability of high frequency (5 kHz) planar array echosounders to rapidly detect low level turbulence (below 200 meters) and quantify the results. This thesis involves design improvements of previously developed echosounder arrays and associated software. Particularly, this thesis demonstrates that tighter packing of elements in a planar acoustic array produces better side lobe reduction than less densely packed arrays. This results in higher energy density in the main lobe and increased performance. Also included in this thesis is a computer method which allows relatively accurate beam pattern prediction from any given planar array.

Descriptors :   *ACOUSTIC DETECTION, *ATMOSPHERIC MOTION, ACOUSTIC ARRAYS, ALTITUDE, ARRAYS, COMPUTER PROGRAMS, COMPUTERS, DENSITY, ENERGY, GROUND LEVEL, HIGH FREQUENCY, LOW LEVEL, PACKAGING, PARTICLE BEAMS, PATTERNS, PERTURBATIONS, PLANAR STRUCTURES, PREDICTIONS, PROFILES, REAL TIME, REDUCTION, SIDELOBES, STRUCTURES, TEMPERATURE, THESES, TURBULENCE, DISTORTION, LASER BEAMS

Subject Categories : Acoustic Detection and Detectors
      Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE