ENA/KASACR/D1 - Minor data issues

The v-channel velocity (uncorrected_mean_doppler_velocity_v) is incorrectly filled with 
NaNs. H-channel is correct. 

The receiver gain (r_calib_receiver_gain_hc and r_calib_receiver_gain_vc) is incorrect. 
This does not affect the data quality. 

The incorrect v-channel calibration constant (r_calib_radar_constant_v) is reported in the 
file. The correct value should be: -20.1884289 (files at the top of the hour) or 
-17.6669998 (files from 20 minutes after the top of the hour) 

Similarly, the reported signal-to-noise ratio (signal_to_noise_ratio_cross_polar_v) is 
calculated using the incorrect v-channel calibration constant, and is biased by a constant 
value of -0.1999974

The reflectivity is calculated with the correct calibration constant and is unaffected.

The h-channel velocity can be used in lieu of the v-channel velocity values. 


null


null


null

The v-channel SNR can be corrected by adding 0.1999974 to the values.

• calibrated_radar_receiver_gain_v_cross_polar_channel(r_calib_receiver_gain_vc)
• calibrated_radar_receiver_gain_v_co_polar_channel(r_calib_receiver_gain_hc)
• Radar constant, vertical cross-polar channel 2(r_calib_radar_constant_v)
• Radial mean Doppler velocity from vertical channel, positive for motion away
  from the instrument, uncorrected(uncorrected_mean_doppler_velocity_v)
• Signal-to-noise ratio, Cross-pol for vertical channel(signal_to_noise_ratio_cross_polar_v)