Final
190401 -99.00 -99.00 -0.90  0.20
190402 -99.00 -99.00 -0.90  0.08 rain; Zdr via BB; Zdr not stable
190403 -99.00 -99.00 -0.90  0.20 rain
190404 -99.00 -99.00 -0.90  0.20
190405 -99.00 -99.00 -0.90  0.20 rain; Zdr via BB
190406 -99.00 -99.00 -0.90  0.20
190407 -99.00 -99.00 -0.90  0.20
190408 -99.00 -99.00 -0.90  0.20 rain
190409 -99.00 -99.00 -0.90  0.25 rain; Zdr via BB; Z via SC 4/9; APU compare w/i 0.5 dB.
190410 -99.00 -99.00 -0.90  0.25
190411 -99.00 -99.00 -0.90  0.25
N2 purge 4/11-4/12
RCA jumped up by +0.9 dB after N2 purge -- unknown why.
Update:  PW changed from 0.8 to 0.6 us resulting in power change.
This has been corrected on 4/18. Absolute Z bias is approx 0.0 dB until
PW change on 4/18
190412 -99.00 -99.00  0.00  0.25 rain
190413 -99.00 -99.00  0.00  0.25 rain; Zdr via BB
190414 -99.00 -99.00  0.00  0.25 rain
190415 -99.00 -99.00  0.00  0.25 rain; severe storms
Zdr system offset gain adjustment effective 4/16/19 (subtracted 0.07 dB)
Update:  This adjustment was not correct!!  See notes from 4/24.
190416 -99.00 -99.00  0.00  0.18
190417 -99.00 -99.00  0.00  0.18
PW change back to correct value of 0.8 micro_s so Z bias continues
190418 -99.00 -99.00 -0.90  0.18
190419 -99.00 -99.00 -0.50  0.18 
190420 -99.00 -99.00 -0.50  0.18; Zdr via BB; Z via SC; Disd confirmed
190421 -99.00 -99.00 -0.50  0.18
190422 -99.00 -99.00 -0.50  0.18
190423 -99.00 -99.00 -0.50  0.18
Zdr system offset gain adjustment effective 4/24/19 (subtract -0.18 dB)
This is on the NPOL1 computer
190424 -99.00 -99.00 -0.50  0.02  Zdr Bias set from 4/26 rain
190425 -99.00 -99.00 -0.50  0.02
Switched to NPOL2 computer -- forgot to set system gain to correct value from 4/24
190426 (1404-1711 Z)  -99.00 -99.00 -0.50  0.18 rain; severe convection
System gain reset to 4/24 value on NPOL2
190426 (1712-2359 Z)  -99.00 -99.00 -0.50  0.02 verified with BB; rain;severe
190427 -99.00 -99.00 -0.50  0.00
190428 -99.00 -99.00 -0.50  0.00
190429 -99.00 -99.00 -0.50  0.00
190430 -99.00 -99.00 -0.50  0.00