TWP/SMET/C2 - Instrument failure

Upper wind sensor failed. Wind direction was reported at a near constant value of 69 
degrees and was significantly different than the lower wind sensor's direction values. Sensor 
replaced.

• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #1 direction vector average(wind1_dir_vec_avg)

TWP/VCEIL/C2 - Ceilometer failure

Large data gaps began occurring frequently at the TWP Nauru site 26 February at 06Z.  
Prior to 25 February, optical cross talk errors had been observed.  Beginning on 25 February, 
data errors were observed.  By 26 February, these errors were exhibiting themselves as 
extended data gaps.  These gaps became increasingly frequent between 2/26 and 3/4.  All 
data are missing after 20050304.1550.

The instrument was replaced on 29 March and after some subsequent configuration work, the 
instrument was revived just after 00Z on 1 April.

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Time offset of tweaks from base_time(time_offset)
• Warning and alarm status bits(status_string)
• east longitude for all the input platforms.(lon)
• Percentage of nominal factory setting (0 to 999%)(receiver_sensitivity)
• Vertical visibility(vertical_visibility)
• Laser temperature(laser_temperature)
• Altitude of highest signal(alt_highest_signal)
• Second lowest cloud base height(second_cbh)
• 6 character string describing instrument measurement parameters(measurement_parameters)
• Degrees from vertical (-15 to +90)(tilt_angle)
• GPS raw data filename(filename)
• Detection status. See details(detection_status)
• north latitude for all the input platforms.(lat)
• altitude above sea levelaltunits(alt)
• Flag indicating aeri retrieval status(status_flag)
• Third cloud base height(third_cbh)
• Percentage of nominal factory setting (0 to 999%)(laser_pulse_energy)
• Lowest cloud base height detected.(first_cbh)
• Time offset from base_time(base_time)
• distance to center of range bin after correcting for offset in sync(range)
• Millivolts at internal ADC input (0 to 2500)(background_light)
• Millivolts at internal ADC input(window_contamination)
• SUM of detected and normalized backscatter(sum_backscatter)

TWP/SMET/C2 - Reprocess: Incorrect Units Listed for Vapor Pressure

The netcdf header file incorrectly listed the units of Vapor Pressure as hPa when in fact 
they were kPa.

• Vapor pressure standard deviation(vappress_sd)
• Vapor pressure mean(vappress_mean)

TWP/MPL/C2 - Missing data

The MPL was turned off due to a dead detector.

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Time offset from midnight of date of file. For CO data, this is identical to
  time_offset and is included for compatibility.(time)
• Laser temperature(laser_temp)
• Repetition rate, or Trigger Frequency of the laser(trigger_freq)
• Maximum altitude retrieved from multichannel scalar card.(max_altitude)
• Sum of raw backscatter counts per bin prior to ANY corrections.(total_counts)
• Time in nanoseconds for each range bin of multichannel scalar card.(range_bin_time)
• Angle of inclination with respect to horizontal(transceiver_altitude_angle)
• Background signal(background_signal)
• Energy output per pulse of transmitted laser beam at 523 nm (Doubled Nd-YLF)(energy_monitor)
• Number of laser pulses summed during measurement interval(shots_summed)
• Angle of orientation with respect to true geographic north(transceiver_azimuth_angle)
• Voltage level which operates the A/D card and the detector(voltage_05)
• Amount of time laser pulse lags behind the scalar trigger(laser_scalar_sync_offset)
• Time offset of tweaks from base_time(time_offset)
• Voltage level which operates the thermistor(voltage_10)
• east longitude for all the input platforms.(lon)
• Time offset from base_time(base_time)
• north latitude for all the input platforms.(lat)
• Width of range-bins calculated from range_bin_time(range_bin_width)
• altitude above sea levelaltunits(alt)
• required to correct raw counts for detector deadtime prior to all other
  corrections.(deadtime_correction)
• Amount of time the scalar lags behind the sync trigger(scalar_sync_offset)
• Distance from leading edge of first range bin to the center of each bin.(range_bins)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Preliminary cloud base height above ground level(preliminary_cbh)
• Number of laser pulses summed during measurement interval(shots_sum)
• Height of bins above ground level for the temperature, retrieved water vapor,
  and pressure profile(height)
• Detector temperature(detector_temp)
• Instrument temperature(instrument_temp)
• distance to center of range bin after correcting for offset in sync(range)
• Assumed zero-range bin number\(assumed_zero_range_bin)
• Attenuated backscatter(detector_counts)
• Repetition rate, or Trigger Frequency of the laser(pulse_rep)
• Voltage level which operates the energy monitor(voltage_15)
• Filter temperature(filter_temp)
• effective range offset due to poor sync between laser firing and A/D trigger.(range_offset)
• value represents date when configuration is first applicable as YYYYMMDD(property)
• Amount of time the actual laser pulse lags behind the sync trigger(laser_sync_offset)

TWP/SMET/C2 - Reprocess: Barometric Data Changed from hPa to kPa

Barometric pressure data was converted from hPa to kPa in order to standardize the 
measurement units among ARM sites and to conform to accepted standard units determined by the 
scientific community.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C2 - Reprocess: Tipping bucket rain gauge added

A tipping bucket rain gauge was added to the SMET suite of instruments effective 20060926. 
 Two new variables (count and rain amount) were added at the end of the twpsmet60sC1.b1 
datastream.  When reprocessing of this datastream occurs these variables will be added 
with -9999 (missing) as the value for dates prior to gauge installation.

• Time offset from base_time(base_time)