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New Dielectric Measurement Data to Determine the Permittivity of Seawater at 1.4313 HzThis paper describes the new measurements - made in 2010-2011 - of the dielectric constant of seawater at 1.413 GHz using a resonant cavity technique. The purpose of these measurements is to develop an accurate relationship concerning the dependence of the dielectric constant of seawater on temperature and salinity for use by the Aquarius inversion algorithm. Aquarius is a NASA/CONAE satellite mission launched in June of 2011 with the primary mission of measuring global sea surface salinity with a 1.413 GHz radiometer to an accuracy of 0.2 psu. A brass microwave cavity resonant at 1.413 GHz has been used to measure the dielectric constant of seawater. The seawater is introduced into the cavity through a capillary glass tube having an inner diameter of 0.1 mm. The change of resonant frequency and the cavity Q value are used to determine the real and imaginary parts of the dielectric constant of seawater. Measurements are automated with Visual Basic software developed at the George Washington University. In this paper, new results from measurements made since September 2010 will be presented for salinities of 30, 35 and 38 psu with a temperature range of 0 C to 35 C in intervals of 5 C. These measurements are more accurate than earlier measurements made in 2008. The new results will be compared to the Klein-Swift (KS) and Meissner-Wentz (MW) model functions. The importance of an accurate model function will be illustrated by using these model functions to invert the Aquarius brightness temperature to retrieve the salinity values. The salinity values will be compared to co-located in situ data collected by Argo buoys.
Document ID
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Lang, R.
(George Washington Univ. Washington, DC, United States)
Zhou, Y.
(George Washington Univ. Washington, DC, United States)
Utku, C.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Levine, D.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 25, 2013
Publication Date
July 22, 2012
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
Meeting Information
Meeting: International Geoscience and Remote Sensing Symposium (IGARSS)
Location: Munich
Country: Germany
Start Date: July 22, 2012
End Date: July 27, 2012
Sponsors: Institute of Electrical and Electronics Engineers
Distribution Limits
Public Use Permitted.
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