Up-scaling effects in passive microwave remote sensing: ESTAR 1.4 GHz measurements during SGP '97

Abstract

Passive microwave radiation measurements over sparsely vegetated surfaces during the Southern Great Plain Experiment are used to determine spatial up-scaling effects. For various distributions of geophysical parameters, the diff erences between mean soil moisture derived from high reso lution (800 by 800m2) 1.4 GHz brightness temperatures and soil moisture calculated from mean brightness tempera tures at larger scales are compared. For spatial resolutions of 31.42km2, the effects of these non-linearities in radiative transfer at 1.4 GHz do not yield differences in estimated volumetric surface soil moisture (0.5 cm) exceeding 0.02 [cm3cm3].