Seasonal comparison of C-band and Ku-band backscatter coefficients over vegetation regions

Spaceborne scatterometry, although originally used to measure winds over oceans, has been useful in the study of vegetation over different regions of the world. For example, scatterometer measurements of the normalized radar cross section, sigma degrees have been used for tropical vegetation classification and in studies of the freeze/thaw cycles of Boreal forests. From September 1996 through June 1997 both the Ku-band NASA Scatterometer (NSCAT) and the C-band ERS-2 AMI scatterometer were operating. This provides a unique opportunity to simultaneously characterize large scale vegetation response at both bands. In this paper we examine the seasonal response of vegetation in North America using both sensors. Observations of the seasonal cycles are discussed.