The bit rate is used to calculate data size of each acquisition. This will be used to “qualify” each swath with a Data size parameter.
It can also be used in the quota constraint, to limit the amount of planned acquisitions according to cumulated aquired volume (GBytes)
See more here
Polarisation is for SAR instruments.
See more here:
com/SaVoir/help/content/6. advanced/constraints/ polarizations/polarizations. htm