A new simplified method for measuring the albedo of limited extent targets

Albedo is important in the research fields of atmospheric sciences, forestry, urban climatology, building energy sciences, and several others. Here we establish a new simplified method for measuring the albedo of limited extent targets in field. Back-to-back pyranometers are centered and leveled over the target to measure the incident radiation and the reflected radiation. A circular baffle with an aperture at the bottom is assembled around the lower pyranometer's detector to make the detector receiving the reflected radiation from the target only. Measurement is calibrated by covering the target with a spectrally non-selective diffuse mask. We use the proposed method to measure the albedo of typical land covers; the measured results were then compared against the measured albedo attained using the ASTM E1918-06 standard. The comparison shows close agreements, indicating that the proposed method is reliable to measure the albedo of a limited extent target and can serve as a simplified alternative to ASTM E1918-06.