Altogether 75 ENVISAT ASAR alternating polarization data were acquired over two VALERI test sites, boreal and sub-Arctic, in 2004. The swath range from IS1 to IS6 was studied. In both test sites a linear relationship between the VV/HH backscattering ratio and leaf area index (LAI) was found. In the boreal test site about 20 cases out of 30 the R2 value exceeded 0.6 already for mean LAI values of 43 plots and corresponding truncated mean backscattering values of distributions obtained from 43 circles of 90 m radius. For the sub-Arctic test site high R2 values required inclusion of a larger number of pixels in the mean VV/HH backscattering ratio. Also the regression parameter values were slightly different from those obtained at the boreal site. All swaths could be used for LAI estimation, but larger incidence angles are preferred due to the smaller pixel size.
|Julkaisu||IEEE Transactions on Geoscience and Remote Sensing|
|Tila||Julkaistu - heinäkuuta 2007|
|OKM-julkaisutyyppi||A1 Julkaistu artikkeli, soviteltu|