TWP/SMET/C1 - Reprocess: ORG Data has very small rainrate values

The ORG data is collected via analog signal and not digital.  Therefore, we continuously 
collect data even when no rain is occurring.  We also capture small events such as leaves, 
large bugs, dust, etc blowing through the measurement path.  Because this discrete event 
occurs quickly the value is usually captured for 1 or 2 seconds.  This value is then 
averaged to the minute producing rainrate on the order of .009 mm/hr or less.  These values 
are not indicative of rain and should be removed from the record or summing over long 
periods can bias the climate record.  We are reprocessing the data to remove these small 
values and are adjusting the collection program to remove them before ingest.

• precipitation minimum(precip_min)
• Precipitation maximum(precip_max)
• Precipitation standard deviation(precip_sd)
• Precipitation mean(precip_mean)

TWP/SMET/C3 - Reprocess: ORG Data has very small rainrate values

The ORG data is collected via analog signal and not digital.  Therefore, we
continuously collect data even when no rain is occurring.  We also capture small events 
such as leaves, large bugs, dust, etc blowing through the measurement path.  Because this 
discrete event occurs quickly the value is usually captured for 1 or 2 seconds.  This 
value is then averaged to the minute producing rainrate on the order of .009 mm/hr or less.  

These values are not indicative of rain and should be removed from the record or summing 
over long periods can bias the climate record.  We will reprocess the data to remove these 
small values.

• Precipitation standard deviation(precip_sd)
• Precipitation maximum(precip_max)
• precipitation minimum(precip_min)
• Precipitation mean(precip_mean)

TWP/SMET/C2 - Reprocess: ORG Data has very small rainrate values

The ORG data is collected via analog signal and not digital.  Therefore, we continuously 
collect data even when no rain is occurring.  We also capture small events such as leaves, 
large bugs, dust, etc blowing through the measurement path.  Because this discrete event 
occurs quickly the value is usually captured for 1 or 2 seconds.  This value is then 
averaged to the minute producing rainrate on the order of .009 mm/hr or less.  

These values are not indicative of rain and should be removed from the record or summing 
over long periods can bias the climate record.  We will reprocess the data to remove these 
small values.

• Precipitation mean(precip_mean)
• precipitation minimum(precip_min)
• Precipitation maximum(precip_max)
• Precipitation standard deviation(precip_sd)

TWP/SMET/C2 - 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.

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

TWP/SMET/C3 - Reprocess: Station Pressure values reported in hPa instead of kPa.

An incorrect program was entered into the datalogger.  This program did not convert the 
station pressure from hPa to kPa.  This made the values larger by a factor of 10 and caused 
the QC bit to be tripped.

• Barometric Pressure(atmos_pressure)

TWP/SMET/C1 - Optical Rain Gage Inoperative

Beginning on 02/07/2009, the trending between the TBRG and ORG began to look poor, one 
recording precip when the other was not and vice versa.  After a while the ORG quit 
registering any precip at all.  ORG was replaced.

• precipitation minimum(precip_min)
• Precipitation maximum(precip_max)
• Precipitation standard deviation(precip_sd)
• Precipitation mean(precip_mean)

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

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