ISFF/ISFS has several PSP and PIR radiometer to measure hemispheric broadband visible and
infrared radiation, respectively. These are often deployed in pairs to measure radiation
incoming and outgoing from the surface.
PSP (pyranometers) are calibrated by NOAA/GMD against standard pyranometers on their roof
(now at Table Mountain).
PIR (pyrgeometers) are planned to be calibrated in the EOL calibration laboratory using a
dual temperature-controlled oil bath.
ISFS has added microprocessor-based A/D boards inside each of these sensors to save and to
apply the calibration coefficients.
Cross-sensitivities are known for these sensors (PSP response to infrared and PIR response
to visible radiation) and are characterized in the field by manually blocking out direct sunlight.