期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2009
卷号：XXXVIII-8/W3
页码：309
出版社：Copernicus Publications
摘要：In the changing global environment there is a need for an operational system for monitoring of world food crop production using satellite observations. It is useful in two primary missions – food security in developing countries, and forecasting production available for global market of agricultural crops. In the present study, grids of size (i) 5oX5o (ii) 1oX1o (iii) 30'X30' (iv) 15'X15' (v) 7.5'X7.5' and (vi) 5'X5' were generated and percent crop area was calculated for each grid of all sizes using MERIS landuse/landcover data of 300 m resolution. The grid size of 15'X15' was found to be optimum for global monitoring, as there is not much change in the distribution of the grids after reducing the sample size. Using the 'cumulative square-root of frequency method five stratas was defined, which reduces the variance of the population estimate by sampling
