Estimating the depostion dates of arid-zone alluvial fans using surface roughness from spaceborne radar backscatter- Mr. Guy Hetz
The current study is located in the southeastern part of the Negev desert, Israel on the late Pleistocene – Holocene Shehoret alluvial fan sequence. High resolution (0.5 cm) 3D roughness measurements were collected using a ground-based LIDAR (Leica HDS 3000) and these show a robust relationship between independently obtained OSL surface age and surface roughness; the fan surfaces become smoother with time over 103-105 yr timescales.
Spaceborne backscatter radar data respond primarily to surface slope, roughness at a scale comparable to the radar wavelength, and other parameters such as dielectric properties of the surface. Therefore, radar can provide a good quantitative indication of surface roughness in arid zones, where vegetation cover is low.
The results show a relationship between surface age and roughness and the radar cross section extracted from polarimetric spaceborne data. The best correlation is found in cross polarization (HV), L-band measured at an incidence angle of 38°.