LWP - The LWP camera appears to have two behavioral trends in sensitivity degradation (Teays and Garhart 1990). The division occurs at approximately 1984.5, which corresponds to the time this camera became the default camera. Post-1984.5 data are corrected using a linear fit (Bevington 1969) to the ratios in that time period, while images taken prior to 1984.5 are corrected using a linear interpolation between each pre-1984.5 degradation ratio. The fluxes of corrected pre-1984.5 data will be less accurate than the fluxes of corrected post-1984.5 data due to the higher uncertainty in the degradation ratios for the early data. Fortunately little science data (except for calibration images) were taken using this camera during the pre-1984.5 time period, so the impact on the entire archive is minimal.
LWR - As is the case with the LWP camera, the LWR exhibits two trends with the dividing point occurring at approximately the same time. However, since the LWR is a closed data set, the binned degradation ratios were fit with a fourth-order polynomial covering the entire time period.
SWP - The SWP sensitivity degradation for the post-1979.5 epoch is represented by a linear relationship. The 1978.5 to 1979.5 epoch degradation ratios, which exhibit a behavior unlike the post-1979.5 epoch, were fit using a linear interpolation between each discrete point (Garhart 1992c).