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)
• 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.

• 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)
• 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.

• lo_spd_arith_avg
• lo_spd_min
• lo_spd_vec_avg
• up_spd_min
• up_spd_arith_avg
• lo_spd_max
• up_spd_max
• up_spd_sd
• lo_spd_sd
• 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)
• 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

• temp_sd
• Vapor pressure mean(vappress_mean)
• Mean Air Temperature or Hardware Error(temp_mean)
• vappress_sd

TWP/SMET/C2 - Barometer data incorrect

Beginning 05/20, atmos_pressure exceeded MAX between ~21:00 and 01:00 UTC on most days.  
The inlet tube was accidentally pinched in the door of the logger enclosure artificially 
increasing the atmospheric pressure during the listed times.  Only a few hours exceeded 
max limits.

• Barometric Pressure(atmos_pressure)

TWP/SMET/C1 - Reprocess: Barometric pressure data scaled incorrectly

The barometer data was scaled incorrectly when a new program was loaded into the 
datalogger.  The pressure data was reported as mb (hPa) instead of the standard kPa.  So, in 
essence the value was a factor of ten to large.

• Barometric Pressure(atmos_pressure)

TWP/SMET/C2 - Induced wind speed when calm

The upper and lower wind sensors were not trending well at wind speed below 1 m/s.  Both 
sensors were showing values above 0m/s when calm.  The lightning protector was at fault 
resulting in an induced wind voltage during calm conditions.

Users should subtract any offset found (for example 0.19 m/s for upper wind speed) when 
the wind speeds are flat-lined.  The offset value was not consistent.

• lo_spd_arith_avg
• lo_spd_min
• lo_spd_vec_avg
• up_spd_min
• up_spd_arith_avg
• lo_spd_max
• up_spd_max
• up_spd_vec_avg

TWP/SMET/C3 - Tower Lowered for Maintenance

The tower was lowered for annual anemometer changes.  The wind data is suspect.

• lo_spd_sd
• lo_spd_vec_avg
• lo_spd_min
• lo_dir_sd
• up_spd_arith_avg
• lo_spd_max
• up_spd_vec_avg
• up_dir_sd
• up_spd_max
• up_spd_sd
• up_spd_min
• lo_dir_vec_avg
• lo_spd_arith_avg
• up_dir_vec_avg

TWP/SMET/C2 - Tower Lowered for Maintenance

Data is suspect due to the tower being lowered.

• vappress_sd
• lo_spd_arith_avg
• relh_sd
• lo_spd_min
• up_dir_vec_avg
• lo_dir_vec_avg
• temp_sd
• lo_spd_vec_avg
• Vapor pressure mean(vappress_mean)
• up_spd_min
• up_dir_sd
• up_spd_max
• Mean Air Temperature or Hardware Error(temp_mean)
• up_spd_vec_avg
• lo_dir_sd
• Relative humidity mean(relh_mean)
• up_spd_arith_avg
• lo_spd_max
• up_spd_sd
• lo_spd_sd