@book{JRC32291, editor = {}, address = {Ispra (Italia)}, year = {2005}, author = {Gallego Pinilla F}, isbn = {}, abstract = {The TREES Project made an estimation of the change in tropical rainforest between 1990 and 1997. Forest change was carefully mapped and quantified on a sample of 100 sites. Each site corresponded to a Landsat-TM frame or quarter of frame. The tropical belt was stratified using a coarse forest map and deforestation hot spots delineated by a group of regional experts. The units for stratification were hexagonal tiles of a spherical tessellation. Hexagons were linked with Landsat observation units. The sampling scheme allowed the computation of forest change estimates with their precision and confidence intervals. However the use of hexagonal tessellations, that can provide a good tool for global sampling frames, was not necessary in this case and it introduced additional complication and reduced the efficiency of the procedure. }, title = {Hexagonal Tessellations to Sample Sites for the Assessment of Tropical Forest Change}, url = {}, volume = {}, number = {}, journal = {}, pages = {}, issn = {}, publisher = {JRC}, doi = {} }