TWP/SMET/C1/C2 - Switch to new Data Header Formats not timely

On April 1, 2001 at 00:00:00 new data header with consistent variable naming conventions, 
etc were to be used for all sites, all data streams.  At the TWP sites the time of the 
movement to the new convention did not occur precisely at 00:00:00.  The following data 
files contain between 40 seconds and 20 minutes of data from 4/1/02 in the old format.  The 
delayed format change did not affect data quality in any way.

twpsmet60sC1.a1.20010401.000001.cdf
twpsmet60sC1.b1.20010401.000001.cdf
twpsmet60sC2.a1.20010401.000000.cdf
twpsmet60sC2.b1.20010401.000000.cdf

• Battery Voltage(internal_voltage)
• base time(base_time)
• Logger panel temperature(logger_temp)
• Tipping bucket raingauge count total(tbrg_count_total)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Lower sensor, wind speed minimum(lo_spd_min)
• Lower sensor, wind direction vector average(lo_dir_vec_avg)
• Upper sensor, wind speed arithmetic average(up_spd_arith_avg)
• precipitation minimum(precip_min)
• Precipitation maximum(precip_max)
• Dummy altitude for Zeb(alt)
• Lower sensor, wind direction standard deviation(lo_dir_sd)
• Upper sensor, wind speed minimum(up_spd_min)
• Upper sensor, wind direction standard deviation(up_dir_sd)
• Upper sensor, wind direction vector average(up_dir_vec_avg)
• Tipping bucket raingauge total(tbrg_total)
• Vapor pressure standard deviation(vappress_sd)
• Mean Relative Humidity(relh_mean)
• Mean Air Temperature or Hardware Error(temp_mean)
• Lower sensor, wind speed standard deviation(lo_spd_sd)
• Upper sensor, wind speed standard deviation(up_spd_sd)
• time(time)
• lon(lon)
• Upper sensor, wind speed vector average(up_spd_vec_avg)
• lat(lat)
• Lower sensor, wind speed maximum(lo_spd_max)
• Precipitation mean(precip_mean)
• Std Dev of Air Temperature(temp_sd)
• Lower sensor, wind speed arithmetic average(lo_spd_arith_avg)
• Time offset of tweaks from base_time(time_offset)
• Vapor pressure mean(vappress_mean)
• Precipitation standard deviation(precip_sd)
• Barometric Pressure(atmos_pressure)
• Lower sensor, wind speed vector average(lo_spd_vec_avg)
• Upper sensor, wind speed maximum(up_spd_max)

• Upper sensor, wind speed maximum(up_spd_max)
• base time(base_time)
• Lower sensor, wind speed arithmetic average(lo_spd_arith_avg)
• Lower sensor, wind speed maximum(lo_spd_max)
• precipitation minimum(precip_min)
• Battery Voltage(internal_voltage)
• Precipitation standard deviation(precip_sd)
• Upper sensor, wind speed minimum(up_spd_min)
• Upper sensor, wind direction standard deviation(up_dir_sd)
• Upper sensor, wind speed vector average(up_spd_vec_avg)
• Time offset of tweaks from base_time(time_offset)
• Tipping bucket raingauge total(tbrg_total)
• Lower sensor, wind direction vector average(lo_dir_vec_avg)
• Dummy altitude for Zeb(alt)
• Logger panel temperature(logger_temp)
• Upper sensor, wind speed standard deviation(up_spd_sd)
• Vapor pressure mean(vappress_mean)
• Lower sensor, wind speed minimum(lo_spd_min)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Barometric Pressure(atmos_pressure)
• Vapor pressure standard deviation(vappress_sd)
• lat(lat)
• time(time)
• Precipitation maximum(precip_max)
• Upper sensor, wind direction vector average(up_dir_vec_avg)
• Lower sensor, wind direction standard deviation(lo_dir_sd)
• Mean Relative Humidity(relh_mean)
• Mean Air Temperature or Hardware Error(temp_mean)
• Upper sensor, wind speed arithmetic average(up_spd_arith_avg)
• lon(lon)
• Lower sensor, wind speed standard deviation(lo_spd_sd)
• Tipping bucket raingauge count total(tbrg_count_total)
• Std Dev of Air Temperature(temp_sd)
• Lower sensor, wind speed vector average(lo_spd_vec_avg)
• Precipitation mean(precip_mean)

• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Precipitation mean(precip_mean)
• base time(base_time)
• Vapor pressure standard deviation(vappress_sd)
• Wind #2 speed maximum(wind2_spd_max)
• Time offset of tweaks from base_time(time_offset)
• precipitation minimum(precip_min)
• lon(lon)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• External voltage(external_voltage)
• Battery Voltage(internal_voltage)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Precipitation maximum(precip_max)
• Mean Air Temperature or Hardware Error(temp_mean)
• Dummy altitude for Zeb(alt)
• Temperature maximum(temp_max)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #2 direction standard deviation(wind2_dir_sd)
• Relative humidity minimum(relh_min)
• Wind #1 speed minimum(wind1_spd_min)
• Logger panel temperature(logger_temp)
• Bit data. See details.(bit_data)
• Temperature minimum(temp_min)
• Barometric Pressure(atmos_pressure)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Precipitation standard deviation(precip_sd)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 speed minimum(wind2_spd_min)
• Relative humidity maximum(relh_max)
• Vapor pressure mean(vappress_mean)
• Mean Relative Humidity(relh_mean)
• Std Dev of Air Temperature(temp_sd)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• lat(lat)

• Dummy altitude for Zeb(alt)
• Wind #1 speed maximum(wind1_spd_max)
• Battery Voltage(internal_voltage)
• Std Dev of Air Temperature(temp_sd)
• base time(base_time)
• Mean Air Temperature or Hardware Error(temp_mean)
• Wind #2 speed maximum(wind2_spd_max)
• Barometric Pressure(atmos_pressure)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Mean Relative Humidity(relh_mean)
• lat(lat)
• Temperature maximum(temp_max)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Vapor pressure standard deviation(vappress_sd)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Logger panel temperature(logger_temp)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Time offset of tweaks from base_time(time_offset)
• Bit data. See details.(bit_data)
• Vapor pressure mean(vappress_mean)
• Temperature minimum(temp_min)
• Precipitation standard deviation(precip_sd)
• Relative humidity minimum(relh_min)
• precipitation minimum(precip_min)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation maximum(precip_max)
• Wind #2 direction standard deviation(wind2_dir_sd)
• External voltage(external_voltage)
• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #2 speed minimum(wind2_spd_min)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• lon(lon)
• Precipitation mean(precip_mean)
• Relative humidity maximum(relh_max)

TWP/SMET/C1 - Negative rainfall rates

Due to limitations of the Zeno dataloggers all voltage measurements
from the optical rain gauge (ORG) were converted to rainfall rates. 
This resulted in negative values for rain rates.  Any value below 0.10 mm/hr should be 
considered to be 0 mm/hr.  New dataloggers 
alleviated this problem.  New loggers were installed 03/09/2004 @ 2243 GMT.

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

TWP/SMET/C1 - Reprocess: Barometric pressure units change

Barometric pressure data during this time period is reported in hPa.  After this time, the 
data have been converted to kPa to standardize the measurement units among ARM sites and 
to conform to accepted standard units determined by the scientific community.

• Barometric Pressure(atmos_pressure)

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(base_time)

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.

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