A Baseline Surface Radiation Network (BSRN) instrumentation is present at CIAO observatory. The system includes a solar tracker, two pyranometers, a pyrgeometer and an pyrheliometer. The instruments are produced by Kipp & Zonen and are able to measure baseline surface radiation according to BSRN standard. According to “WORLD CLIMATE RESEARCH PROGRAMME BASELINE SURFACE RADIATION NETWORK (BSRN) Operations Manual”, a BSRN site must deliver following measurements with a rate of at least 1 measurement per minute and indicated accuracy:

Direct solar radiation – 0.5% – 1.5W/m2

Diffuse radiation – 2% – 3W/m2

Global radiation – 2% – 5W/m2

Reflected solar radiation – 3%

Downward and upward solar radiation – 2% – 3W/m2