Up-to-date metric aerial photographs covering specific areas are not always available. This is one of the main problems in Brazil when area sampling techniques for crop area estimation are used. This work aims to evaluate fused Landsat7-ETM+ images for ground survey data collection and to identify and map land elements in order to replace the use of aerial photographs. The spectral bands 3; 4; 5 and 7 of the ETM+ sensor were used in different RGB combinations merged with the panchromatic band 8 to produce images with better spatial resolution using IHS fusion technique. The resulting images were printed in a 1:25,000 scale and used during the ground survey campaign for 85 sampling units. Results pointed out that the fused images allowed identifying and mapping land elements in all the analyzed sampling units. Therefore, fused ETM+ images presented a great potential for ground survey data collection and to identify and map land elements for crop area estimation based on area sampling techniques.
sampling; remote sensing; image processing
