TWP/MPL/C3 - Loss of Polarization

Polarization has deteriorated so that cross polarization signal is now essentially the 
same as circular

Do not calculate depolarization ratios

• Background signal standard deviation, cross-pol(background_signal_std_cross_pol)
• Background signal, cross pol data(background_signal_cross_pol)
• Attenuated backscatter, cross pol(signal_return_cross_pol)