NSA/MPL/C1 - laser head failure

On 2002-04-28 the laser energy was observed to decrease throughout the day.  Although low 
clouds continued to be detected, by the end of the day the output laser energy was about 
10% of nomimal.  This decrease continued throughout 2002-04-29 to the extent that clouds 
were no longer detected.  The source of failure was eventually determined to be the laser 
head, requiring the MPL to be shipped for repair.  The MPL was reinstalled on 2002-08-28 
at about 01:00 UTC.  

MPL NSA data from 2002-04-29 through 2002-08-27 (inclusive) should not be used.

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

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

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

• Angle of orientation with respect to true geographic north(transceiver_azimuth_angle)
• Amount of time the actual laser pulse lags behind the sync trigger(laser_sync_offset)
• Number of laser pulses summed during measurement interval(shots_summed)
• Time offset from base_time(base_time)
• Background signal(background_signal)
• Amount of time the scalar lags behind the sync trigger(scalar_sync_offset)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• required to correct raw counts for detector deadtime prior to all other
  corrections.(deadtime_correction)
• Maximum altitude retrieved from multichannel scalar card.(max_altitude)
• Laser temperature(laser_temp)
• Number of laser pulses summed during measurement interval(shots_sum)
• Distance from leading edge of first range bin to the center of each bin .(range_bins)
• Preliminary cloud base height above ground level(preliminary_cbh)
• Voltage level which operates the A/D card and the detector(voltage_05)
• value represents date when configuration is first applicable as YYYYMMDD(property)
• Height of bins above ground level for the temperature, retrieved water vapor,
  and pressure profile(height)
• Time offset from midnight of date of file. For CO data, this is identical to
  time_offset and is included for compatibility.(time)
• north latitude for all the input platforms.(lat)
• Repetition rate, or Trigger Frequency of the laser(trigger_freq)
• Time in nanoseconds for each range bin of multichannel scalar card.(range_bin_time)
• Time offset of tweaks from base_time(time_offset)
• effective range offset due to poor sync between laser firing and A/D trigger.(range_offset)
• Detector temperature(detector_temp)
• altitude above sea levelaltunits(alt)
• Voltage level which operates the energy monitor(voltage_15)
• Sum of raw backscatter counts per bin prior to ANY corrections.(total_counts)
• Voltage level which operates the thermistor(voltage_10)
• Amount of time laser pulse lags behind the scalar trigger(laser_scalar_sync_offset)
• Filter temperature(filter_temp)
• Instrument temperature(instrument_temp)
• Width of range-bins calculated from range_bin_time(range_bin_width)
• Repetition rate, or Trigger Frequency of the laser(pulse_rep)
• east longitude for all the input platforms.(lon)
• Energy output per pulse of transmitted laser beam at 532 nm (Doubled Nd -YLF)(energy_monitor)
• Angle of inclination with respect to horizontal(transceiver_altitude_angle)
• distance to center of range bin after correcting for offset in sync(range)

NSA/MPL/C1 - Laser Q-Switch Problem

At about 22:52 UTC on 2004/01/19, the NSA MPL appears to have suffered a temporary failure 
of the laser Q-Switch.  This results in a complete loss of lidar data immediately 
thereafter.  The problem was resolved (at least for the time being) by disconnecting and 
reconnecting the Q-Switch cable on 2004/01/24 at about 00:16 UTC.  Data after this time appears 
good.

• Voltage level which operates the thermistor(voltage_10)
• Distance from leading edge of first range bin to the center of each bin .(range_bins)
• Maximum altitude retrieved from multichannel scalar card.(max_altitude)
• distance to center of range bin after correcting for offset in sync(range)
• Energy output per pulse of transmitted laser beam at 532 nm (Doubled Nd -YLF)(energy_monitor)
• Height of bins above ground level for the temperature, retrieved water vapor,
  and pressure profile(height)
• Time offset from base_time(base_time)
• effective range offset due to poor sync between laser firing and A/D trigger.(range_offset)
• Number of laser pulses summed during measurement interval(shots_summed)
• Instrument temperature(instrument_temp)
• Background signal(background_signal)
• Filter temperature(filter_temp)
• east longitude for all the input platforms.(lon)
• Time offset from midnight of date of file. For CO data, this is identical to
  time_offset and is included for compatibility.(time)
• Time in nanoseconds for each range bin of multichannel scalar card.(range_bin_time)
• Voltage level which operates the A/D card and the detector(voltage_05)
• Detector temperature(detector_temp)
• Laser temperature(laser_temp)
• Voltage level which operates the energy monitor(voltage_15)
• Preliminary cloud base height above ground level(preliminary_cbh)
• Attenuated backscatter(detector_counts)
• Repetition rate, or Trigger Frequency of the laser(pulse_rep)
• north latitude for all the input platforms.(lat)
• Time offset of tweaks from base_time(time_offset)
• Width of range-bins calculated from range_bin_time(range_bin_width)
• altitude above sea levelaltunits(alt)

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

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

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

• required to correct raw counts for detector deadtime prior to all other
  corrections.(deadtime_correction)
• Number of laser pulses summed during measurement interval(shots_sum)
• Distance from leading edge of first range bin to the center of each bin .(range_bins)
• Voltage level which operates the A/D card and the detector(voltage_05)
• value represents date when configuration is first applicable as YYYYMMDD(property)
• Height of bins above ground level for the temperature, retrieved water vapor,
  and pressure profile(height)
• north latitude for all the input platforms.(lat)
• Repetition rate, or Trigger Frequency of the laser(trigger_freq)
• Time in nanoseconds for each range bin of multichannel scalar card.(range_bin_time)
• Detector temperature(detector_temp)
• altitude above sea levelaltunits(alt)
• Sum of raw backscatter counts per bin prior to ANY corrections.(total_counts)
• Instrument temperature(instrument_temp)
• Repetition rate, or Trigger Frequency of the laser(pulse_rep)
• east longitude for all the input platforms.(lon)
• distance to center of range bin after correcting for offset in sync(range)
• Angle of orientation with respect to true geographic north(transceiver_azimuth_angle)
• Amount of time the actual laser pulse lags behind the sync trigger(laser_sync_offset)
• Number of laser pulses summed during measurement interval(shots_summed)
• Time offset from base_time(base_time)
• Background signal(background_signal)
• Amount of time the scalar lags behind the sync trigger(scalar_sync_offset)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Maximum altitude retrieved from multichannel scalar card.(max_altitude)
• Laser temperature(laser_temp)
• Preliminary cloud base height above ground level(preliminary_cbh)
• Time offset from midnight of date of file. For CO data, this is identical to
  time_offset and is included for compatibility.(time)
• Time offset of tweaks from base_time(time_offset)
• effective range offset due to poor sync between laser firing and A/D trigger.(range_offset)
• Voltage level which operates the energy monitor(voltage_15)
• Voltage level which operates the thermistor(voltage_10)
• Amount of time laser pulse lags behind the scalar trigger(laser_scalar_sync_offset)
• Filter temperature(filter_temp)
• Width of range-bins calculated from range_bin_time(range_bin_width)
• Energy output per pulse of transmitted laser beam at 532 nm (Doubled Nd -YLF)(energy_monitor)
• Angle of inclination with respect to horizontal(transceiver_altitude_angle)

NSA/MPL/C1 - Hardware Failure/Missing Data

Data are missing during this extended period due to a hardware failure.

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

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

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

• Angle of orientation with respect to true geographic north(transceiver_azimuth_angle)
• Amount of time the actual laser pulse lags behind the sync trigger(laser_sync_offset)
• Number of laser pulses summed during measurement interval(shots_summed)
• Time offset from base_time(base_time)
• Background signal(background_signal)
• Amount of time the scalar lags behind the sync trigger(scalar_sync_offset)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• required to correct raw counts for detector deadtime prior to all other
  corrections.(deadtime_correction)
• Maximum altitude retrieved from multichannel scalar card.(max_altitude)
• Laser temperature(laser_temp)
• Number of laser pulses summed during measurement interval(shots_sum)
• Distance from leading edge of first range bin to the center of each bin .(range_bins)
• Preliminary cloud base height above ground level(preliminary_cbh)
• Voltage level which operates the A/D card and the detector(voltage_05)
• value represents date when configuration is first applicable as YYYYMMDD(property)
• Height of bins above ground level for the temperature, retrieved water vapor,
  and pressure profile(height)
• Time offset from midnight of date of file. For CO data, this is identical to
  time_offset and is included for compatibility.(time)
• north latitude for all the input platforms.(lat)
• Repetition rate, or Trigger Frequency of the laser(trigger_freq)
• Time in nanoseconds for each range bin of multichannel scalar card.(range_bin_time)
• Time offset of tweaks from base_time(time_offset)
• effective range offset due to poor sync between laser firing and A/D trigger.(range_offset)
• Detector temperature(detector_temp)
• altitude above sea levelaltunits(alt)
• Voltage level which operates the energy monitor(voltage_15)
• Sum of raw backscatter counts per bin prior to ANY corrections.(total_counts)
• Voltage level which operates the thermistor(voltage_10)
• Amount of time laser pulse lags behind the scalar trigger(laser_scalar_sync_offset)
• Filter temperature(filter_temp)
• Instrument temperature(instrument_temp)
• Width of range-bins calculated from range_bin_time(range_bin_width)
• Repetition rate, or Trigger Frequency of the laser(pulse_rep)
• east longitude for all the input platforms.(lon)
• Energy output per pulse of transmitted laser beam at 532 nm (Doubled Nd -YLF)(energy_monitor)
• Angle of inclination with respect to horizontal(transceiver_altitude_angle)
• distance to center of range bin after correcting for offset in sync(range)