Data Quality Reports for Session: 136023 User: ruchi0114 Completed: 07/11/2011


TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D100616.2NSA/VCEIL/C1 - Small gaps in datansavceil25kC1.b1
D100719.1NSA/VCEIL/C1 - Gaps in datansavceil25kC1.b1


DQRID : D100616.2
Start DateStart TimeEnd DateEnd Time
12/03/2009210706/15/20102143
Subject:
NSA/VCEIL/C1 - Small gaps in data
DataStreams:nsavceil25kC1.b1
Description:
When the ceilometer was replaced, small gaps in the netCDF files occurred due to the 
presence of '?' characters in the backscatter and header records of the raw data that could 
not be ingested. It is unknown whether this was caused by a poor CPU board or 
incompatibilities with the computer configuration (hyper-threading). The problem was corrected when 
the instrument and computer were both replaced. 

During this period, approximately 3% of data are missing each hour due to this problem.
Measurements:nsavceil25kC1.b1:
  • Third cloud base height(third_cbh)
  • alt_highest_signal
  • receiver_sensitivity
  • laser_temperature
  • Second lowest cloud base height(second_cbh)
  • Lowest cloud base height detected.(first_cbh)
  • Vertical visibility(vertical_visibility)
  • tilt_angle
  • time_offset
  • measurement_parameters
  • status_flag
  • sum_backscatter
  • range
  • base_time
  • Backscatter(backscatter)
  • status_string
  • background_light
  • window_contamination
  • laser_pulse_energy
  • detection_status


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DQRID : D100719.1
Start DateStart TimeEnd DateEnd Time
06/15/2010215906/17/20102201
Subject:
NSA/VCEIL/C1 - Gaps in data
DataStreams:nsavceil25kC1.b1
Description:
When the CT25K ceilometer was replaced with a new CL31, checksum errors began occurring at 
regular 6-min intervals and several things were done to diagnose the problem, including 
changing the serial cable and trying different computer types. It was finally corrected 
by replacing the computer with one in which hyperthreading was disabled by default in the 
BIOS.
Measurements:nsavceil25kC1.b1:
  • Third cloud base height(third_cbh)
  • alt_highest_signal
  • receiver_sensitivity
  • laser_temperature
  • Second lowest cloud base height(second_cbh)
  • Lowest cloud base height detected.(first_cbh)
  • Vertical visibility(vertical_visibility)
  • tilt_angle
  • time_offset
  • measurement_parameters
  • status_flag
  • sum_backscatter
  • range
  • base_time
  • Backscatter(backscatter)
  • status_string
  • background_light
  • window_contamination
  • laser_pulse_energy
  • detection_status


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