Water use control methods and water resources planning are of high priority. In irrigated agriculture, the right way to save water is to increase water use efficiency through better management. The present work validates procedures and methodologies using remote sensing to determine the water availability in the soil at each moment, giving the opportunity for the application of the water depth strictly necessary to optimise crop growth (optimum irrigation timing and irrigation amount). The analysis is applied to the Irrigation District of Divor, Evora, using 7 experimental plots, which are areas irrigated by centre pivot systems, cultivated to maize. Data were determined from images of the cultivated surface obtained by satellite and integrated with atmosphere and crop parameters to calculate biophysical indicators and indices of water stress in the vegetation Normalized Difference Vegetation Index (NDVI), Kc, and Kcb. Therefore, evapotranspiration (ETc) was estimated and used to calculate crop water requirement, together with the opportunity and the amount of irrigation water to allocate. Although remote sensing data available from satellite imagery presented some practical constraints, the study could contribute to the validation of a new methodology that can be used for irrigation management of a large irrigated area, easier and at lower costs than the traditional FAO recommended crop coefficients method. The remote sensing based methodology can also contribute to significant saves of irrigation water. (C) 2016 Elsevier B.V. All rights reserved.