TWP/MPL/C2 - Power Oscillation

There is an oscillation that shows up in the reflected power and the power monitor.  This 
oscillation shows up clearly whenever there is an absence of low (< ~5 km) clouds. Cloud 
return signals tend to be much larger than the level of this oscillation; however, it may 
introduce problems for studying aerosol distributions.  The end date of this DQR is 
artificial in that this is as far as the QC went.

• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Energy output per pulse of transmitted laser beam at 523 nm (Doubled Nd-YLF)(energy_monitor)

TWP/C2/MPL Detector

The MPL detector failed and was shut down.

• Time offset of tweaks from base_time(time_offset)
• Time offset from base_time(base_time)
• MPL Cloth et al. Algorithm Significance Mask(SigniMaskMplCloth)
• Range Heights (center of radar sample volume)(Heights)

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

• Instrument temperature(instrument_temp)
• Laser temperature(laser_temp)
• Repetition rate, or Trigger Frequency of the laser(pulse_rep)
• Cloud base height (for first cloud above height threshold)(cloud_base_height)
• Time offset from base_time(base_time)
• Flag indicating whether the beam was extinguished at indicated cloud top(cloud_top_attenuation_flag)
• Relative random error in backscatter profiles(random_error)
• Detector temperature(detector_temp)
• east longitude for all the input platforms.(lon)
• Cloud mask(cloud_mask_1)
• Height of bins above ground level for the temperature, retrieved water vapor,
  and pressure profile(height)
• north latitude for all the input platforms.(lat)
• Background signal(background_signal)
• Cloud mask(cloud_mask_2)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• altitude above sea levelaltunits(alt)
• Energy output per pulse of transmitted laser beam at 523 nm (Doubled Nd-YLF)(energy_monitor)
• Time offset of tweaks from base_time(time_offset)
• Number of laser pulses summed during measurement interval(shots_summed)
• The update time of the historical baseline used for the cloud boundary
  determination of this sample(baseline_update_time)
• Cloud top height (for highest cloud sensed)(cloud_top_height)

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

• MPL Clothiaux et al. Algorithm Cloud Mask Occurrence(CloudMaskMplCloth)
• Range Heights (center of radar sample volume)(Heights)
• Time offset from base_time(base_time)
• Time offset of tweaks from base_time(time_offset)

TWP/MPL/C2 - Reprocess: Global metadata error

During the time period specified, the global metadata attribute "averaging_int" is 
reported as 30 seconds when the value for this attribute should be 60 seconds.

• Time offset of tweaks from base_time(time_offset)

TWP/MWR/C2 - software upgrade (version 3.29)

The MWR operating program was upgraded to version 3.29 on 30 July 1999. This version 
included a beam width correction as well as provided the capability to automatically level the 
elevation mirror (that is, to automatically detect and correct offsets in the elevation 
angle stepper motor position.)
   
The improvement in the quality of the tip curves resulting from the auto-leveling has been 
dramatic: differences in the brightness temperatures at 3 airmasses (19.5 and 160.5 
degrees) have been reduced from +/- 5 K to +/- 0.5 K. In order to take full advantage of this 
improvement to detect and reject cloudy tip curves, the minimum value of the 
goodness-of-fit coefficient for a valid tip curve has been increased from 0.995 to 0.998.

The data prior to July 30 1999 do not include beam-width and mirror-leveling corrections.

• Mean 23.8 GHz sky brightness temperature(tbsky23)
• Mean total water vapor amount along LOS path(vap)
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Mean total liquid water amount along LOS path(liq)