Japan Meteorological Agency (JMA)
Dobson Spectrophotometer

Dobson spectrophotometers are used for ground-based measurement of total ozone. These widely used instruments are based on monochromators, which compare solar UV intensity at a few fixed pairs of wavelengths. One wavelength is chosen to absorb ozone more strongly than the other pairs. The total column ozone amount is calculated from instrument calibration factors, previous knowledge of ozone absorption cross sections, and geometric factors related to the position of the sun.

Last Updated: 2008.04.07