SGP/MPL/C1 - Metadata errors

The latitude, longitude and altitude of the Micropulse Lidar
(MPL) were incorrectly entered into the ARM database.  The 
correct location of the SGP.C1 MPL is:
   Lat: 36.606N
   Lon: 97.485W
   Alt:    316m

• north latitude for all the input platforms.(lat)
• east longitude for all the input platforms.(lon)
• altitude above sea levelaltunits(alt)

• north latitude for all the input platforms.(lat)
• altitude above sea levelaltunits(alt)
• east longitude for all the input platforms.(lon)

Instrument misalignment report

A low-resolution (300 m) MPL system (unit number 04) was installed at the
SGP site in April '97 upon the laser diode failure of the 02 unit in
March.  Calibration of this instrument in August found that the optics
were misaligned causing a near range focusing error in the data.  
Calibration files produced for this data, while acceptable, do not 
completely correct for the problem.  As a result, aerosol property 
retrievals using this data are not suggested.  Cloud boundary heights, 
though appear satisfactory.  This system was removed from SGP in early 
September

• Aerosol volume backscattering coefficient at 355 nm(backscatter)

Laser Output Energy Monitor at Zero

Energy monitor reading for laser output is at zero for intermittant
one-minute averaged shots during this flagged data period.  From the
lidar equation progressing to normalized relative backscatter the
laser energy is required and is a denominator.  Therefore a value of
zero will render the product as infinite.  Shots where this has taken
place are left as zeros.  It is suggested that the time period
19970425 2123 - 19970428 1459
be avoided for any quantitative analysis.

• Aerosol volume backscattering coefficient at 355 nm(backscatter)

Laser Output Energy Monitor at Zero

Energy monitor reading for laser output is at zero for intermittant
one-minute averaged shots during this flagged data period.  From the
lidar equation progressing to normalized relative backscatter the
laser energy is required and is a denominator.  Therefore a value of
zero will render the product as infinite.  Shots where this has taken
place are left as zeros.  It is suggested that the time periods 
19970902 2211 - 19970903 1359,
19970907 1445 - 19970908 1544,
and
19970910 2142 - 19970910 2355
be avoided for any quantitative analysis.

• Aerosol volume backscattering coefficient at 355 nm(backscatter)

SGP/MPL - Missing data due to blown detector

Sometime early 11/11 the detector on the
MPL-004 blew out.  The Detector was replaced by Albert Mendoza.
The instrument was operational on Jan. 23, 1999.

Link this to P981119.2 that reported the blown detector and the
corrective action taken

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

• (Development raw data stream - documentation not supported)

• Time offset of tweaks from base_time(time_offset)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• altitude above sea levelaltunits(alt)
• Time offset from base_time(base_time)
• Average cloud base height used in the retrieval(cbh)

• Background signal(background_signal)
• Instrument temperature(instrument_temp)
• Time offset of tweaks from base_time(time_offset)
• Cloud base height (for first cloud above height threshold)(cloud_base_height)
• Energy output per pulse of transmitted laser beam at 532 nm (Doubled Nd -YLF)(energy_monitor)
• north latitude for all the input platforms.(lat)
• Cloud mask(cloud_mask_2)
• Height of bins above ground level for the temperature, retrieved water vapor,
  and pressure profile(height)
• Number of laser pulses summed during measurement interval(shots_summed)
• Repetition rate, or Trigger Frequency of the laser(pulse_rep)
• The update time of the historical baseline used for the cloud boundary
  determination of this sample(baseline_update_time)
• Cloud top height (for highest cloud sensed)(cloud_top_height)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Flag indicating whether the beam was extinguished at indicated cloud top(cloud_top_attenuation_flag)
• Detector temperature(detector_temp)
• Laser temperature(laser_temp)
• Cloud mask(cloud_mask_1)
• east longitude for all the input platforms.(lon)
• Time offset from base_time(base_time)
• Relative random error in backscatter profiles(random_error)
• altitude above sea levelaltunits(alt)