The radiometric response of the EOS-AM1 Multi-angle Imaging SpectroRadiometer (MISR) is to be measured throughout the six-year mission. To accomplish this task, MISR makes routine use of an on-board calibrator, aircraft flyovers, field exercises, and comparisons to other on-orbit and aircraft sensors. Analyses of these data results in a deliverable called the Ancillary Radiometric Product (ARP). This file contains the radiometric response parameters for all nine cameras and four spectral bands. The instrument on-board calibrator is exercised bi-monthly, and the next ARP time-series file is created shortly thereafter. This file is used in MISR standard product generation to convert the sensor output into a measure of the incident radiance, and is used to process all MISR data acquired in the subsequent two months. Thereafter the process is repeated and the new ARP time-series file is utilized. Due to improvements in the processing algorithms, updates are allowed to the inactive ARP data files. These revisions would be used should a previously generated MISR data product be reordered and reprocessed, as would be the case should an investigator desire to make use of all science software algorithm upgrades. This paper discusses the investigations and algorithm changes that have occurred in the production of the ARP since launch, and discusses changes to the Level 1B data that might be expected should data be reprocessed.