Engineering topics

Bredow, J. W.

Publications and source records attributed to Bredow, J. W..

2 records

NASA NTRS1992

Attenuation behavior of solid dense random media at microwave frequencies

To better understand scattering from nontenuous dense random media such as sea ice and snow, attenuation measurements have been performed on two different types of random media with ka values ranging from 0.5 to 0.7, and 1.5 to 2.1. Experimental results are presented for wave propagation in plane slabs of finite thickness composed of a random distribution of identical, finite scatterers, and a random distribution of scatterers with narrow size distribution. The observed behavior is described in terms of attenuation versus volume fraction, and the behavior of attenuation versus frequency. Results presented are compared to the behavior reported by some earlier experiments where the medium properties are different.

Nadimi, S. A.↗

NASA NTRS1992

Circular and linear polarization inverse SAR imaging of simple deterministic targets and statistically known randomly rough surfaces using constant and varying illumination

In order to study mechanisms of scattering and their relative contributions to synthetic aperture radar (SAR) and inverse SAR images, a special measurement facility has been constructed. It can be used to generate images in which the target is illuminated from a constant direction as the receiver is rotated in azimuth, and the target is illuminated from various directions as the receiver is rotated in azimuth. The imaging system performance is discussed, and images obtained using both approaches are compared, for a variety of simple targets and statistically known randomly rough surfaces.

Bredow, J. W.↗