REBS Radiation and Soil Sensors



Net radiometers are used to determine the total net radiation (sum of visible and infrared; difference between incoming and outgoing) near the Earth's surface. We use the Model Q*7 made by REBS (Radiation and Energy Balance Systems, Inc.). They have two calibration coefficients -- one for positive values (generally daytime, dominated by visible radiation) and another, smaller, value for negative values (nighttime, infrared). ISFF also routinely measures all 4 of these radiation components at up to 4 locations individually with pyranometers and pyrgeometers, but usually still uses net radiometers for redundancy.

In the Q7 manual provided by Campbell Scientific, there is a correction for convective cooling as a function of wind speed, that we often apply.

ISFF also uses the REBS heat flux plates (HFT) and soil temperature sensors to determine the heat flux into, and heat storage by, the top layer of soil.

These sensors are used to determine components of the total surface energy balance.