Category:sunskylunarphotometer

This category uses the form Instrument.

URI: https://vocabulary.actris.nilu.no/actris vocab/sunskylunarphotometer

label: sun sky lunar photometer (en)

description: Photometer mounted on a tracking system to always point towards the sun to measure the direct sun radiance. Can alternatively pointed towards the moon as light source, or towards the sky to measure sky radiance. Can be equipped with spectral filters to measure the direct sun radiance at targeted wavelengths. By calibration, the optical depth of the atmosphere can be inferred from the direct sun / moon radiance. By using assumptions on the atmospheric temperature and pressure profile, or corresponding information from weather forecast models or radio sonde soundings, the optical depth due to aerosol particles in the atmosphere column can be calculated. (en)