Data Quality Reports for Session: 101061 User: loknath Completed: 08/10/2006


TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D040424.2TWP/MPL/C2 - Sun-shade dropping during daytimetwpmplC2.00, twpmplC2.a1, twpmplcmask1clothC2.c1, twpmplsmask1clothC2.c1
D060621.2TWP/MPL/C2 - Optical throughput unacceptabletwpmplC2.00, twpmplC2.a1


DQRID : D040424.2
Start DateStart TimeEnd DateEnd Time
09/15/2003000010/11/20032359
Subject:
TWP/MPL/C2 - Sun-shade dropping during daytime
DataStreams:twpmplC2.00, twpmplC2.a1, twpmplcmask1clothC2.c1, twpmplsmask1clothC2.c1
Description:
The MPL sunshade began to act erratically on 9/15/2003 dropping frequently throughout day 
and night.  To reduce data loss, the sunshade was restrained from blocking the MPL during 
the night.  Thus, cloud detection during the night is satisfactory, but daytime 
measurements are frequently interspersed with episodes of beam-block.
Measurements:twpmplsmask1clothC2.c1:
  • 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)

twpmplC2.00:
  • Raw data stream - documentation not supported(Raw data stream - documentation not supported)

twpmplC2.a1:
  • 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)
  • 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)

twpmplcmask1clothC2.c1:
  • 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)


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DQRID : D060621.2
Start DateStart TimeEnd DateEnd Time
02/01/2003000011/12/20041900
Subject:
TWP/MPL/C2 - Optical throughput unacceptable
DataStreams:twpmplC2.00, twpmplC2.a1
Description:
The optical throughput of the MPL at Nauru is below an acceptable level. Despite an 
extended stay to address the problem in Feb 2003, the problem was unresolved.  An additional 
repair was attempted in July 2003 with no significant success.  Several optical components 
were replaced and the system was repeatedly re-aligned.  

The system appears to have been properly collimated as the shape of the signal is 
appropriate for both near and far range.  The magnitude of the signal was simply too low.  This 
signal decrease was apparent in ambient background values as well as from atmospheric 
signal, so the impact on data quality was not as severe as might otherwise be the case.  The 
MPL was still capable of detecting high altitude cirrus (day and night) but the 
sensitivity was reduced.
Measurements:twpmplC2.00:
  • Raw data stream - documentation not supported(Raw data stream - documentation not supported)

twpmplC2.a1:
  • Attenuated backscatter(detector_counts)


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