TWP/MPL/C2 - Nauru MPL Laser Diode accidentally off

The emission from the laser diode supply was accidentally off.  The Instrument
Mentor, Connor Flynn, called Nauru directly and had them turn the laser emission
back on.  Backscatter and cloud base data during the period between 
2000-11-11 00:00 GMT and 2000-11-13 22:00 GMT should be regarded as bad 
or incorrect while background light data and local temperature values are 
acceptable.

• Aerosol backscatter coefficient at 355 nm(backscatter)
• Preliminary cloud base height(preliminary_cbh)

TWP/MPL/C2 - Laser emission accidentally turned off

Shortly after 00:00 GMT on 11/11/00, the MPL Energy Monitor value dropped
abruptly to zero.  At about 22:00 GMT on 11/13/00, the remote handset for
the laser diode supply was used to turn the laser back on.

• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• Preliminary cloud base height above ground level(cbh)
• base time(base_time)
• Dummy altitude for Zeb(alt)
• lon(lon)

• Time offset of tweaks from base_time(time_offset)
• base time(base_time)
• MPL Cloth et al. Algorithm Significance Mask(SigniMaskMplCloth)
• Height of Center of Each Range Bin(Heights)

• null(Raw data stream - documentation not supported)

• null(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, measured by MPL(cloud_base_height)
• 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)
• lon(lon)
• Cloud mask(cloud_mask_1)
• Array of heights for the range gates(height)
• lat(lat)
• Background Signal(background_signal)
• Cloud mask(cloud_mask_2)
• Aerosol backscatter coefficient at 355 nm(backscatter)
• Dummy altitude for Zeb(alt)
• Laser output energy per pulse(energy_monitor)
• Time offset of tweaks from base_time(time_offset)
• Number of laser shots recorded(shots_summed)
• The update time of the historical baseline used for the cloud boundary
  determination of this sample(baseline_update_time)
• cloud top height(cloud_top_height)

• time(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)
• Laser output energy per pulse(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 backscatter coefficient at 355 nm(backscatter)
• Number of laser pulses summed during measurement interval(shots_sum)
• Preliminary cloud base height(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 shots recorded(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)
• lon(lon)
• base time(base_time)
• lat(lat)
• Dummy altitude for Zeb(alt)
• Amount of time the scalar lags behind the sync trigger(scalar_sync_offset)
• Array of heights for the range gates(height)
• range(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 of last configuration change as yyyymmdd(property)
• Amount of time the actual laser pulse lags behind the sync trigger(laser_sync_offset)

• MPL Cloth et al. Algorithm Cloud Mask(CloudMaskMplCloth)
• Height of Center of Each Range Bin(Heights)
• base time(base_time)
• Time offset of tweaks from base_time(time_offset)

TWP/MPL/C1 - Missing data

Data are missing and unrecoverable.

• Voltage level which operates the A_D card and the detector(voltage_5)
• Laser Temperature(laser_temp)
• Voltage level which operates the thermistor(voltage_10)
• Preliminary cloud base height above ground level(cbh)
• Aerosol backscatter coefficient at 355 nm(backscatter)
• Number of laser shots recorded(shots_summed)
• Background Signal(background_signal)
• Instrument Temperature(instrument_temp)
• Filter Temperature(filter_temp)
• Repetition Rate, or Trigger Frequency of the laser(pulse_rep)
• Detector Temperature(detector_temp)
• base time(base_time)
• Laser output energy per pulse(energy_monitor)
• Dummy altitude for Zeb(alt)
• Voltage level which operates the energy monitor(voltage_15)
• GPS raw data filename(filename)
• lon(lon)
• lat(lat)
• Time offset of tweaks from base_time(time_offset)

TWP/MPl/C2 - Laser power failure events

When the new laser for the MPL at Nauru was installed the handset was incorrectly set to
manual instead of automatic. This meant that when the power was interrupted to the I van 
(even

observers when they saw no laser light. This went on from 29 Jan at 23:00

• Aerosol backscatter coefficient at 355 nm(backscatter)

TWP/C1 - Incorrect elevation reported in Manus Data

Bill Clements reports we have been using 6m MSL as the station elevation of Momote 
(Manus).  This was based on information posted near the station barometer in the Momote Weather 
Service Office.  It turns out that the official WMO station elevation for Momote is 4m 
MSL and the upper air elevation is 5m MSL.

All Manus instruments except the sonde station are at 4m MSL. The sonde launching station 
is at 5m MSL.

• Dummy altitude for Zeb(alt)

• Dummy altitude for Zeb(alt)

• Dummy altitude for Zeb(alt)

TWP/MPL/C2 - laser diode failure

On Nov 20, 2001, following a data gap of several hours the MPL energy monitor reading 
showed an abrupt decrease of about 60%.  The laser energy continued to decrease to a reading 
of zero by Nov 23.  Cloud detection is satisfactory through Nov 21, but is not 
satisfactory after this time until the laser diode was replaced on Jan 08, 2002.  Data between the 
dates of 2001-11-22 and 2002-01-08 inclusive is not useful.

• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• Preliminary cloud base height above ground level(cbh)
• base time(base_time)
• Dummy altitude for Zeb(alt)
• lon(lon)

• Time offset of tweaks from base_time(time_offset)
• base time(base_time)
• MPL Cloth et al. Algorithm Significance Mask(SigniMaskMplCloth)
• Height of Center of Each Range Bin(Heights)

• null(Raw data stream - documentation not supported)

• null(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, measured by MPL(cloud_base_height)
• 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)
• lon(lon)
• Cloud mask(cloud_mask_1)
• Array of heights for the range gates(height)
• lat(lat)
• Background Signal(background_signal)
• Cloud mask(cloud_mask_2)
• Aerosol backscatter coefficient at 355 nm(backscatter)
• Dummy altitude for Zeb(alt)
• Laser output energy per pulse(energy_monitor)
• Time offset of tweaks from base_time(time_offset)
• Number of laser shots recorded(shots_summed)
• The update time of the historical baseline used for the cloud boundary
  determination of this sample(baseline_update_time)
• cloud top height(cloud_top_height)

• time(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)
• Laser output energy per pulse(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 backscatter coefficient at 355 nm(backscatter)
• Number of laser pulses summed during measurement interval(shots_sum)
• Preliminary cloud base height(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 shots recorded(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)
• lon(lon)
• base time(base_time)
• lat(lat)
• Dummy altitude for Zeb(alt)
• Amount of time the scalar lags behind the sync trigger(scalar_sync_offset)
• Array of heights for the range gates(height)
• range(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 of last configuration change as yyyymmdd(property)
• Amount of time the actual laser pulse lags behind the sync trigger(laser_sync_offset)

• MPL Cloth et al. Algorithm Cloud Mask(CloudMaskMplCloth)
• Height of Center of Each Range Bin(Heights)
• base time(base_time)
• Time offset of tweaks from base_time(time_offset)

TWP/MPL/C1 - 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/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/MPL/C3 - 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/MPL/C2 - Reprocess: Incorrect longitude and altitude reported

The longitude of the MPL instrument is reported as -166.916.  The correct longitude is 
+166.916.

The altitude of the MPL instrument is reported as 7.2.  The correct altitude is 7.1 M.

These data will be reprocessed at a low priority.

• Dummy altitude for Zeb(alt)
• lon(lon)