Impact of rain on radar transmittance through building walls

Guillermo C. Gaunaurd; Lam H. Nguyen

doi:10.1117/1.2857452

1 February 2008 Impact of rain on radar transmittance through building walls

Guillermo C. Gaunaurd, Lam H. Nguyen

Author Affiliations +

Optical Engineering, Vol. 47, Issue 2, 026201 (February 2008). https://doi.org/10.1117/1.2857452

Abstract

We study and exactly evaluate the transmittance of microwave energy—below S-band—that goes through thick building walls covered by an external thin layer of rain. The incident radiation penetrates the wet walls at normal incidence, twice in their back-and-forth paths typical of sensing-through-the-wall (STTW) operations. The walls are responsible for most of the loss through the structure in view of their greater thickness, but the water layer contribution is significant, and it is quantitatively evaluated here. The properties of the water layer are expressed in terms of Debye's classical formulation, and those of the walls are obtained from available measurements. A simple homogenization technique is used to generate an "effective permittivity" of the double layer to be able to alternatively treat it as a single equivalent layer—an approximation to the exact values, which yields acceptable results. It is also found that the transmittance T and the reflectance R of a single and double layer could also be expressed in alternative and apparently novel forms that may simplify future calculations. Further, if either R or T were known as well as the layer(s) properties, then either one could be used to obtain the other. Finally, representative plots are displayed, quantitatively showing the (two-way) transmittance degradation that occurs when there is a rain layer on top of the various considered wall materials, and we explain a resonance effect observable in the transmittance plots that shows an oscillatory frequency behavior.

©(2008) Society of Photo-Optical Instrumentation Engineers (SPIE)

Citation Download Citation

Guillermo C. Gaunaurd and Lam H. Nguyen "Impact of rain on radar transmittance through building walls," Optical Engineering 47(2), 026201 (1 February 2008). https://doi.org/10.1117/1.2857452

Published: 1 February 2008

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available