The Open Radar Data Acquisition (ORDA) System will replace the legacy Radar Data Acquisition (RDA) system that is currently part of the NEXRAD fleet. The ORDA system integrates a digital receiver. Many legacy calibration parameters, e.g., SYSCAL, have been replaced with new system calibration parameters, e.g., dBZ0, with the ORDA system. This paper provides a detailed description of manual calibration, automatic on-line calibration & automatic off-line calibration algorithms. Details of test signals and methodology will be presented. And when appropriate, differences to legacy parameters will be identified & explained.