News

Izaña Calibration Campaign, August 2026

It began with a sky slightly clouded by Saharan dust and ended with a much clearer sky (AOD of 0.03).
Every day, we took measurements using a set of 25 Calitoo devices (from 8:00 a.m. to 1:00 p.m. UT). Each photometer records 5 sets of 3 measurements over the course of those 5 hours. The Aeronet network photometers, which we use as a reference, were specifically set to fast mode and take a measurement every 5 minutes.
Calibration involves finding the Aeronet measurement closest in time to a Calitoo measurement and then, through calculation, deriving the three CN0 parameters from it. For each wavelength, the 15 Calitoo measurements yield 15 CN0 values that, in theory, should be identical.
The calibration process involves retaining only those CN0 values that are most similar to one another and form a horizontal line over time. The three lines (red, green, blue) can be found on your calibration report.

The AEMET station at Izaña. The Aeronet network’s photometers are installed at the top of the large white tower.

We were kindly welcomed by Africa Berreto and her team, specialists in aerosol measurements.

During a measurement session.
At this altitude and with five hours of direct sunlight, full UV protection is essential!

And finally, here’s the altitude.