Comparison of Resourcesat-1 AWiFS and SPOT-5 data over managed boreal forest stands
International Journal of Remote Sensing
In this study, the utility of AWiFS data in relation to stem volume estimation for managed boreal forest stands was investigated. Multiple linear regressions were used to predict stem volume (m 3 ha -1 ) with standwise mean spectral values as the independent variables. For comparison, two SPOT-5 images were also used, one with nearly simultaneous acquisition. The adjusted coefficient of determination (R 2 adj ) using AWiFS data to predict stem volume was 0.573 (SE 56.9%) while SPOT had an R 2
... j of 0.598 (SE 55.2%). All bands were negatively correlated, with the SWIR band having the single strongest correlation with stem volume. The best two band predictor of stem volume was the NIR and red band for AWiFS, and the NIR and SWIR bands for SPOT. When stem volume was predicted based on stand size, AWiFS and SPOT produced an R 2 adj of 0.310 and 0.293, respectively, for stands less than 2 ha in size. A steady increase of predictive ability appeared to increase with stand size, with the highest R 2 adj at 20 ha (R 2 adj = 0.677 AWiFS, R 2 adj = 0.692 SPOT). For stands 20 ha and larger, the correlation between stem volume and NIR reflectance increased while decreasing for the visible bands. The explanation behind the trends observed may be due to the management practices in the area. Discriminant analysis of basic forest types showed similar results for AWiFS (65.6% correct) and SPOT (66.4% correct). Cite as: Reese, H., Nilsson, M., and Olsson, H. (2009). Comparison of Resourcesat-1 AWiFS and SPOT-5 data over managed boreal forest stands.