Aursee · method

The burn archive, 2012 to today

How Aursee remembers where fire has been detected since 2012, and what the history figures on each page mean.

What is kept

For every 0.01 degree cell on Earth, about 1.1 km across at the equator, the archive records each UTC day on which at least one VIIRS detection fell inside it. It starts on 20 January 2012, the first day of the Suomi NPP record, and grows every hour.

Keeping one row per cell per day, rather than every detection, keeps the answer to "has this place burned before?" small enough to attach to every fire.

Which satellites

Up to April 2026 the archive is Suomi NPP standard processing, one satellite, reprocessed by NASA. From then on the hourly feed adds NOAA-20 and NOAA-21, which see more fires. The country histories therefore use complete years from the single-satellite record, so every year in a chart is measured the same way.

Detected area is not burned area

The history pages report detected area: the total area of cells with at least one detection. A small fire lights a whole cell, so detected area overstates the ground that burned where fires are small and scattered. A fire that burned between passes or under cloud is missing, which understates it elsewhere. Mapped burned area products exist and give different, usually larger, figures.

What detected area does well is comparison: the same rule applied to every country and every year since 2012. See the country histories.

More on the method

• What a satellite fire detection isHow VIIRS finds active fires from orbit, what a 375 m detection means, and when a fire is not seen.
• Fires in the dark: how satellites find them at nightWhy a fire is easier to see from orbit at night, how VIIRS picks a flame of a few dozen square metres out of a 375 m pixel, and what “burning in darkness” means on the map.
• Fire radiative power (MW)What fire radiative power measures, how Aursee adds it up, and how to compare two fires.
• How detections become firesThe rule Aursee uses to turn individual satellite pixels into fires you can open, name and follow.
• Lightning near a fireHow Aursee checks for lightning before a fire was first seen, and where that check is possible.
• Land cover and roads under a fireWhat kind of ground a fire is burning on, and how many roads are around it: sources and resolution.
• Weather at a fireWhere the wind, humidity and temperature on a fire page come from, and at what time and resolution.
• Data sources and licencesEvery dataset Aursee uses, who publishes it, and the licence it is used under.