Validat ing MODIS burned area products over Cerrado region

Ab stract. We present a validation of three MODIS burned area products, namely AQM/INPE, MCD45A1/NASA and MCD64A1/NASA, covering a 6-year period (2005-2010) over Jalapao, a fire-prone region located in the Cerrado. As reference we use high resolution BA maps derived from Landsat imagery. Because the products to be validated have different spatial resolutions than that of reference maps (i.e. AQM with 1 km, NASA with 500 m and Landsat scars with 30 m), the error matrix was estimated following a new approach based on the assumption of mixed pixels, where the agreement/disagreement between product and reference data are computed taking into account the proportion of BA from reference data within the product pixel. The two NASA products present very low commission errors ( 60%). The AQM product has larger commission errors (20 to 40%) but a large fraction of those (more than 40%) occur at the borders of the scars and may therefore not be strictly viewed as false alarms; there is also a clear reduction of the omission cases (< 40% in all cases). The AQM product presents a clear reduction of omission errors that reflects a higher probability of detection of burned pixels. The new product appears therefore as more sensitive to sub-pixel burned areas, even when working at a lower spatial resolution; this particular feature may be attributed to the use of middle infrared reflectance by the algorithm.