TWP/MWR/C3 - Sun in field of view of radiometer

Each day from approximately 9/15 to 10/9 around local noon, there is an increase in the 
brightness temperature due to the sun being in the field of view of the radiometer.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• 23.8 GHz sky signal(tipsky23)
• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)

TWP/SMET/C3 - Barometer Data Incorrect

The barometer data was incorrect or missing due to water intrusion.

• Barometric Pressure(atmos_pressure)

TWP/SMET/C3 - Water in enclosure

Data became erratic and unreasonable after water intrusion into the enclosure.

• Precipitation mean(precip_mean)
• Vapor pressure standard deviation(vappress_sd)
• Precipitation maximum(precip_max)
• Mean Relative Humidity(relh_mean)
• Mean Air Temperature or Hardware Error(temp_mean)
• Precipitation standard deviation(precip_sd)
• Vapor pressure mean(vappress_mean)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• precipitation minimum(precip_min)
• Std Dev of Air Temperature(temp_sd)

TWP/SMET/C3 - Wind Speed data contain offset due to induced voltage

The marine model of the RM Young wind sensor needs twisted pair shielded cable.  The 
manufacturer did not originally supply the pigtail with twisted pair shielded cable.  Use of 
twisted pair shielded cable for the rest of the cable run to the logger was also not 
specified.  This caused an induced voltage in the wind speed line from the wind direction 
excitation.  The induced voltage varied from sensor to sensor and probably changed anytime 
the cable was replaced or parts of the wind sensor were repaired or replaced. The induced 
voltage has been seen to vary from 0.15 m/s to as much as 1.08 m/s.

• Upper sensor, wind speed maximum(up_spd_max)
• Lower sensor, wind speed minimum(lo_spd_min)
• Lower sensor, wind speed standard deviation(lo_spd_sd)
• Lower sensor, wind speed maximum(lo_spd_max)
• Upper sensor, wind speed arithmetic average(up_spd_arith_avg)
• Lower sensor, wind speed vector average(lo_spd_vec_avg)
• Upper sensor, wind speed minimum(up_spd_min)
• Lower sensor, wind speed arithmetic average(lo_spd_arith_avg)
• Upper sensor, wind speed vector average(up_spd_vec_avg)
• Upper sensor, wind speed standard deviation(up_spd_sd)

TWP/SMET/C3 - Reprocess: Temperature Biased low by 1.06 Degrees

The temperature of the SMET system was biased low by 1.06 Deg C due to a non-precision 
resistor being used int he measurement circuit.  The data will be reprocessed.  Saturation 
Vapor pressure and Vapor pressure will have to be reprocessed also.

Add 1.06 degrees to the temperature data.  

Correct Sat Vap Press using the Buck approximation:
   Es = 6.1121exp((17.502*T)/(240.97 + T) 
where T is the temperature in C.  

Correct Vapor pressure using: E = (RH*Es)/100

• Vapor pressure standard deviation(vappress_sd)
• Mean Air Temperature or Hardware Error(temp_mean)
• Vapor pressure mean(vappress_mean)
• Std Dev of Air Temperature(temp_sd)