Use of L-Band Ground-Based Radiometers for Freeze/Thaw Retrieval in A Boreal Forest Site

Two L-Band radiometers were deployed at a boreal forest site (one above the forest canopy and one below the overstory canopy), to characterize the microwave contributions of the ground and forest canopy on the FreezelThaw (F/T) microwave signal observed by spaceborne L-Band sensors. Preliminary results show that the F/T processes of the ground rather than the overstory canopy primarily contribute to the F/T signal at L-band. However, the radiometer above the canopy did show some sensitivity to F/T of the canopy (5 K), but this sensitivity was much lower compared to the signal induced by the ground F/T (12 K).