COMPARING 2 METHODOLOGIES FOR CROP AREA ESTIMATION IN SPAIN USING LANDSAT TM IMAGES AND GROUND-GATHERED DATA

The results obtained in the estimation of crop areas in the south of Navarra (Spain) are presented. These estimations were carried out using two similar but differential methodologies: one of them based in the area frame sampling procedures developed by the Institute for Remote Sensing Applications (IRSA) of the EEC in Ispra, and the other inspired in the scheme of area frame sampling used by the National Agricultural Statistics Service (NASS) in the United States. Both methods also incorporate spectral information from a landsat TM image. The statistical precision of the estimations made by direct expansion and by regression are quite similar in both cases, obtaining higher values of weighted relative efficiency in the case of square segments (IRSA methodology). The values of the relative efficiency at the individual crop level are good in general, and are similar to those obtained in the experiments carried out by the Institute for Remote Sensing Applications of the EEC.