The UVVIS-FR unit is part of the UVVIS cluster of CREGARS. It is responsible for all the SAOZ/Mini-SAOZ instruments within ACTRIS. Its tasks include:
- developing, maintaining and issuing the proper guidelines and procedures; ;
- providing training, developing and operating the central SAOZ processing and quality control system compliant to the guidelines set forward by the UVVIS working group of NDACC (Network for the Detection of Atmospheric Composition Change) ;
- issuing feedback and status reports to the NFs/users. – providing the needed technical input in the labelling and auditing process.
The SAOZ (Système d’Analyse par Observation Zénithale) is a UV-Visible (300-650 nm) diode array spectrometer developed at the Service d’Aéronomie (now LATMOS) in the late 80’s for monitoring stratospheric ozone after the discovery of the ozone hole.
The SAOZ is using a holographic flat field spectrometer equipped with a 1024 pixels diode array detector looking at sunlight scattered at zenith during twilight.
The data analysed by DOAS (Differential Optical Absorption Spectrometry) method allow the retrieval of daily ozone and NO2 total columns at sunrise and sunset. The instrument operates automatically outdoors and data storage is provided by a computer located inside.
The Mini-SAOZ is a modernized, lightweight version of the SAOZ in which all obsolete components have been replaced. Mini-SAOZ is using a Czerny-Turner spectrometer equipped with a flat-field grating and a CCD detector of 2048×16-pixels. The Mini-SAOZ is designed for indoor operation, utilizing a long optical fiber connected to an outdoor optical head that collects sunlight.