Correction schemes for solar sensors with multiple time constants

A numerical scheme to correct for the delayed response of thermal solar radiation sensors is discussed. The proposed scheme employs only information that can be obtained from the response to a step input and does not require any auxiliary measurements. Furthermore, the scheme is applicable to instruments with any number of time constants and avoids the need for high order numerical derivatives. The development of such a scheme is motivated by a study of the Eppley Normal Incidence Pyrheliometer, which cannot be described accurately by a two-exponential model.