In the framework of the FP6 EUSAAR project (Network Activity NA4, WORCC has constructed an AOD Travelling Standard (TSD) consisting of a PFR and a mobile sun tracker (EKO model STR22). This activity is funded through a sub-contract with the Paul Scherrer Institute from April 2007 to January 2011.
On-site audits will be conducted at EUSAAR and European GAW sites over the project duration. Priority will be given to EUSAAR members followed by GAW and Associate members. As a result of such a “travelling standard” approach it is expected that the following benefits are realised:
Improvement in Quality Assured AOD data.
Minimisation in "down-time" of PFR sun-photometers during off-site calibration at WORCC, Davos.
Closer contact (on-site visits) means that problems can be more quickly resolved.
The solar tracker and PFR were delivered and integrated in March 2008, while calibration against the PFR primary reference trio at Davos occurs 2 - 3 times each year. The below table summarises completed and forthcoming Travelling Standard visits.