error on the knowledge of the orientation of the BRF including the initial alignment measurement error and the alignment stability error
NOTE 1 The initial alignment measurement error is between the Alignment Reference Frame (ARF) and the sensor Boresight Reference Frame (BRF) as measured during on ground calibration.
NOTE 2 The Alignment Stability Error (Calibration to Flight) is the change in the transformation between the sensor Mechanical Reference Frame (MRF) and the sensor Boresight Reference Frame (BRF) between the time of calibration and the start of the in-flight mission.
NOTE 3 The bias can be for the BRF Z-axis directional or the rotational errors around the BRF X, Y- axes.
NOTE 4 For definition of directional and rotational errors see B.5.17.
NOTE 5 Due to its nature, the bias metric value is the same whatever the observation area is.
NOTE 6 The detailed contributors to the bias are given in clause 5.5.