Yes. All alerts processed and published by MapBiomas Alerta go through a rigorous verification process. There are three steps: pre-validation, validation and audit.
- Pre-Validation – includes two steps. The first is the automated elimination of all alerts that overlap with reforestation and agriculture areas present in MapBiomas' annual maps or that have already been detected in previous surveys. After this process, the remaining alerts go through visual analysis with the support of the high resolution monthly mosaics from Planet (images with 3 m resolution) and the analysts select the best pair of satellite images available to represent the moment before and after deforestation. At this point, the fraction of alerts that correspond to cases of false positives is discarded, with the corresponding record of the reason for rejection (forestry, agriculture, seasonality, etc.).
- Validation – validation is performed at the time of sample collection for classification and refinement of the deforested polygon in high resolution images. The technician can rule out cases of false positives, with the corresponding record of the reason for rejection (forestry, agriculture, seasonality, etc.).
- Audit – each refined alert goes through an audit process carried out by a technical supervisor from each biome. In this step, the eventual need to redo any adjustments is evaluated before the final publication of the refined alerts.