This term is defined in ECSS-E-ST-60-21C as
set of activities based on a set of tests allowing to characterise the gyro non-random performance and, when relevant, to define the compensation parameters used to improve the performance

This term is defined in ECSS-S-ST-00-01C as
all the operations for the purpose of determining the values of the errors and, if necessary, other metrological properties of a measuring instrument