Passive microwave sensing of surface characteristics over HAPEX-Sahel area

This study is focused on an area in the sahelian zone (NIGER)where the HAPEX-Sahel experiment took place in 1992. During HAPEX-Sahel, passive microwave data acquired with airborne radiometers (PORTOS and PBMR) as well as soil moisture measurements were collected. The aim of this investigation is to monitor soil moisture and vegetation parameters by combining L and C Bands passive microwave data. Through a relation between soil moisture measurements over 0.5 and 2.5cm top layers, the soil moisture is estimated for PORTOS data using the results derived from PBMR data, The first order radiative transfer model is then applied to extract the vegetation optical thickness and the single scattering albedo at C Band. The current retrieved parameters were compared to what was obtained at C Band from active microwave data over one pixel of ERS1 windscatterometer. The results indicate the possibility to infer surface features over semi-arid environment by combining passive and active microwaves data.