Comparison of evaporation duct height measurement methods and their impact on radar propagation estimates
By: John David Whalen
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1998
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 66
Description: A study was performed to compare shipboard measurements of atmospheric parameters that impact the      evaporation duct and its effect on the propagation of electromagnetic energy from the AEGIS AN/SPY-1      radars. Two ships, USS ANZIO and USS CAPE ST GEORGE, participated in the annual NATO exercise,      BALTOPS, during the summer of 1997. They were equipped with an automated METOC sensor system,      developed by Johns Hopkins University Applied Physics Laboratory, called SEAWASP. SEAWASP provided      continuous measurement of parameters determining near surface refractivity and the evaporative duct      throughout the cruise. SEAWASP data were compared with manual bridge observations in order to illustrate      the difference in propagation conditions assessed by the two methods. Additionally, ERS-1 Scatterometer wind      data were used in conjunction with SEAWASP data to determine the feasibility of incorporating satellite wind      data in determining evaporative duct heights. The automated SEAWASP data was able to depict, with greater      accuracy, the constantly changing duct height conditions whereas the bridge observations, made at hourly      intervals, lacked temporal resolution, thereby missing much of the variation in duct height. The discrepancies in      duct heights between the two measurement systems led to differing propagation ranges resulting in shorter      reaction times to counter threats to the ship.
Notes: "March 1998."

Thesis advisor(s): Kenneth L. Davidson.

Thesis (M.S. in Meteorology and Physical Oceanography) Naval Postgraduate School, March 1998.

Includes bibliographical references (p. 63-64)

Approved for public release; distribution unlimited.

Also available online.

Mode of access: World Wide Web.

System requirements: Adobe acrobat reader.

US Navy (USN) author.

dk/dk cc:9116 8/18/98.