ANALYSIS OF VEGETATION INDEXES FROM LANDS AT TM AND SPOT XS DATA

The objective of this work was to evaluate vegetation indices (Simple Ratio, Normalized Difference and Transformed Vegetation Index) obtaine d on soybean and corn crops, from LANDSAT/TM and SPOT/XS data (acquire d on Feb. 01, 1989). The study area is located in the southeast of Dis trito Federal - Brazil. The vegetation indices were obtained from aver aged values of digital numbers from 20 units (3.6 ha each one) sampled on the studied crops. The results were analysed through correlation m ethod for equal indices but come from different sensor systems. Accord ing this research it was concluded that: the same vegetation indices w ere highly correlated both for soybean and corn crops and both for LAN DSAT/TM and SPOT/XS; and, the lowest observed correlation (0.72) was o ver the soybean crop for the Transformed Vegetation Index.