SBS/MPL/S1 - Degradation of cross-pol component

During this period, the cross polarization component steadily degraded.  It is difficult 
to ascertain the exact date when this began to occur because the atmosphere is light on 
aerosols and has considerable ice particles which leads to apparent cross polarization when 
this may not have been the case.

During the latter half of this deployment, depolarization values are likely too large and 
should be regarded with care.  Cloud determination is likely unaffected.

• Attenuated backscatter, cross pol(signal_return_cross_pol)
• background_signal_std_cross_pol
• qc_signal_return_cross_pol
• background_signal_cross_pol