For ACRIM II and ACRIM III, the stated uncertainty was estimated from the cavity variation.
However, this correction has not been applied to the ERBE and ACRIM data shown in Fig.
Representatives from each of four TSI instrument teams, TIM, ACRIM, DIARAD, and PMO6, would provide an instrument that has a design basically equivalent to their respective flight instrument(s).
2] during the TIM and ACRIM measurements, so as to match the defining aperture area of those instruments.
Original plans for the ACRIM missions called for the replacement device to reach orbit before the first one ceased functioning, which would have allowed scientists to calibrate the new instrument.
Willson used measurements from another satellite monitor, called ERB, as a bridge between the two ACRIM instruments.