PT Unknown AU Acevedo, W TI National assessment of land cover change using the NLCD 1992-2006 database [abs.] BT Forty years of Earth observations... understanding a changing world, William T. Pecora Memorial Symposium on Remote Sensing, 18th PY 2011 LA FY 2012 DE assessment; change; conference abstracts; database; Earth; Earth observation; land; land cover; land cover change; land-cover; NLCD; remote sensing PI Bethesda, Md. ER