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)