All alerts processed and published by MapBiomas Alerta undergo a rigorous verification process consisting of three stages: pre-validation, validation, and audit.

• Pre-validation - involves two steps. The first is an automated process that eliminates all alerts overlapping with reforestation and agricultural areas in the annual MapBiomas maps or those already detected in previous surveys. Alerts that pass this stage are visually assessed using monthly high-resolution Planet mosaics (3-meter resolution images), and the best pair of daily satellite images representing the period before and after deforestation is selected. At this point, false positive alerts are discarded, with the corresponding reason for rejection recorded (silviculture, agriculture, seasonality, etc.). 
• Validation - occurs during the sampling process for classification and refinement of the deforested polygon in high-resolution images. The technician can discard false positives, with the corresponding reason for rejection recorded (silviculture, agriculture, seasonality, etc.).   
• Audit - Each refined alert undergoes an audit process conducted by a technical supervisor for each biome. At this stage, the need for any adjustments before the final publication of the refined alerts is assessed."

Additional details about the validation and publication methodology of the alerts are available at this link: https://alerta.mapbiomas.org/metodo-mapbiomas-alerta/