Calibration of a high frequency monostatic acoustic echosounder
Cherry, David R.
Walters, Donald L.
Davis, David S.
MetadataShow full item record
Atmospheric turbulence degrades a coherent laser beam when it propagates through the atmosphere. Measurement of the atmospheric turbulence provide insight into to underlying mechanisms that produce optical turbulence and suggest possible means to overcome or circumvent the effects of such turbulence. A variety of acoustic, optical and thermal probe instruments provide measurements of atmospheric turbulence. Of these, the acoustic echosounder can measure atmospheric density and velocity irregularities. During the course of previous work, questions arose concerning the calibration of the NPS echosounder. The echosounder appears t detect a higher level of atmospheric turbulence than do other instruments used at the same altitude. This resulting overestimation of atmospheric turbulence could significantly influence programs such as the Advanced Electro-Optic Site (AEOS), a proposed 4 m telescope to be built in Hawaii. This thesis will attempt to identify key components contributing to the sounder calibration including the transducer transmitting and receiving efficiencies as well as their dependence on pressure and atmospheric density. Additionally a modified acoustic echosounder equation will be developed which more accurately profiles the atmospheric turbulence measured by such a sounder.
Approved for public release; distribution is unlimited
Showing items related by title, author, creator and subject.
Corley, M.S.; Santiago, F.; T. Martinez; Agrawal, B.N. (2011);The Navy is interested in horizontal laser propagation studies in a maritime environment, near the ocean surface, for applications including imaging and high-energy laser propagation. The Naval Postgraduate School (NPS) ...
Collins, Joseph C. (Monterey, California: Naval Postgraduate School, 2016-06);Laser weapon systems, unlike conventional weapons, are heavily dependent upon the ever-changing atmospheric conditions in their employment theater. In order to understand the operational effectiveness of a laser weapon, ...
Liu, Jeng-Shiung (Monterey, California. Naval Postgraduate School, 2004-12);Optical turbulence plays an important role in the propagation of electromagnetic waves through the atmosphere because it broadens and distorts the optical beam. A variety of optical, thermal, and acoustic instruments are ...