TWP/SMET/C1 - Upper wind sensor failure

The upper wind speed sensor was binding at low wind speeds.  Comparison to the lower wind 
sensor showed that the upper sensor flat-lines for long periods of time.  The upper 
anemometer was replaced.

• up_dir_sd
• up_spd_max
• up_spd_sd
• up_dir_vec_avg
• up_spd_vec_avg
• up_spd_arith_avg
• up_spd_min

TWP/SMET/C1 - Reprocess: Tipping bucket rain gauge added

A tipping bucket rain gauge was added to the TWP.C1 SMET suite of instruments on 20061017. 
 Effective 20060926, two new variables (count and rain amount) were added to the end of 
the twpsmet60sC1.b1 datastream.  Between 9/26 and 10/17, the data for these two variables 
are filled with zeros.  Users should not use the data during this period as the zeros 
are not representative of the rain fall at the site.  When reprocessing of this datastream 
occurs these variables will be added for the 19961009-20060926 and data from 
19961009-20061017 will be filled with -9999 (missing).

• base_time

TWP/SMET/C1 - Upper winds failure

The upper wind instrument was inoperative resulting in constant wind direction and speed.  
A failed cable was replaced.

• up_dir_sd
• up_spd_max
• up_spd_sd
• up_dir_vec_avg
• up_spd_vec_avg
• up_spd_arith_avg
• up_spd_min

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/C1 - ORG Precip Data Incorrect

Moisture intrusion into the sensor body allowed condensation on the lens of the ORG.  
Continual and long-term precipitation was reported during this time.

• Precipitation minimum(precip_min)
• Precipitation maximum(precip_max)
• precip_sd
• Precipitation mean(precip_mean)

TWP/SMET/C1 - 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_max
• up_spd_max
• lo_spd_vec_avg
• lo_spd_min
• lo_spd_arith_avg
• up_spd_sd
• up_spd_vec_avg
• up_spd_arith_avg
• up_spd_min
• lo_spd_sd

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/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/C1 - Missing RH, Barometer, and ORG data

Atmos_pressure data suddenly went missing on 03/02 at 07:34 UTC and consequently, the 
relative humidity data flatlined. 

Furthermore, after a sudden precipitation event when the max precip rate flag was tripped 
the TBRG total has not agreed with the comparison ORG or the precip rate plot. 

A loose wire connection was fixed 3/22 restoring RH and barometer data.  A damaged cable 
was repaired 5/11 restoring ORG data.

• Relative humidity mean(relh_mean)
• Precipitation minimum(precip_min)
• relh_sd
• Barometric Pressure(atmos_pressure)
• Precipitation maximum(precip_max)
• precip_sd
• Precipitation mean(precip_mean)

TWP/SMET/C1 - Aux (lower) wind sensor failed

The lower wind direction sensor on the C1 site was flatlining at 270 degrees throughout 
most of the daylight hours of the day. During the night the sensor appeared to be working 
fine.

• lo_spd_max
• lo_spd_vec_avg
• lo_spd_min
• lo_spd_arith_avg
• lo_dir_vec_avg
• lo_dir_sd
• lo_spd_sd