Results of combining L- and C-band passive microwave airborne data over the sahelian area

This study focuses on an area in the Sahelian zone, Niger, Western Africa, where the HAPEX-Sahel experiment took place in 1992, During the hydrologic atmospheric pilot experiment in the Sahel (HAPEX-Sahel), passive microwave data were acquired with airborne radiometer, the multifrequency (5 to 90 GH z) and dual polarization sensor, PORTOS, and the four-beam sensor push broo m microwave radiometer (PBMR), operating at 1.4 GHz in H-polarization, The aim of this investigation is to monitor soil moisture and vegetation parame ters by combining Land C-Band passive microwave airborne measurements. Thro ugh the relationships between soil moisture measurements from the 2 cm and 0.5 cm top layers, soil moisture; is estimated for PORTOS data using the es timated soil moisture along the transects covered by the PBMR flights. The simplified radiative transfer model is then used to extract the optical thi ckness and the single scattering albedo of vegetation at C-Band, and to eva luate the vegetation effect on the estimated soil moisture at L-Band, An at tempt to relate the estimated optical thickness from PORTOS data to the mea sured vegetation biophysical parameters water content, biomass, leaf area i ndex (LAI)I is presented.