Photometer performance assessment in Kepler science data processing

This paper describes the algorithms of the Photometer Performance Assessment (PPA) software component in the Kepler Science Operations Center (SOC) Science Processing Pipeline. The PPA performs two tasks: One is to analyze the health and performance of the Kepler photometer based on the long cadence science data down-linked via Ka band approximately every 30 days. The second is to determine the attitude of the Kepler spacecraft with high precision at each long cadence. The PPA component has demonstrated the capability to work effectively with the Kepler flight data.