NSA/MPL/C1 - Detector Failure

Beginning 12/25, the signal return displayed serious aliasing, reflection, or ringing of 
the detector, with a highly repetitive pattern repeating six or more times within the 
lowest 15 km.  On 01/02, the detector became very difficult to put into any type of operating 
condition. When it did operate, the "aliased" signal pattern was still present.

The detector was replaced.

• background_signal_std
• laser_temp
• energy_monitor
• signal_return
• background_signal

NSA/MPL/C1 - Missing data

System was down for detector replacement.

• base_time
• time
• laser_temp
• range_offset
• lon
• signal_return
• dead_time_corrected
• Pressure, associated geometric height, at altitude, NGM model output(height)
• range
• lat
• shots_per_avg
• scope_temp
• polarization_control_voltage
• Preliminary cloud base height above ground level(preliminary_cbh)
• alt
• max_altitude
• time_offset
• background_signal_std
• range_bin_width
• num_bins
• detector_temp
• pulse_rep
• range_bin_time
• polarization_control
• range_bins
• energy_monitor
• background_signal
• num_channels

NSA/MPL/C1 - No cross polarized data

The cross polarizor was not functioning so there is no cross polarized data.  All data 
during the specified period is circularly polarized.

• signal_return

NSA/TSI/C1 - camera lens covered

The shadowband was not properly masking the sun so the camera lens was covered on 4/13 to 
prevent damage to the CCD. On 4/20, the mirror was blown off by a snow storm and the 
instrument was brought inside for repair. The mirror was replaced, the lens uncovered, and 
the instrument reinstalled.

• region.zenith.count.opaque
• count.sub.proczen
• count.sub.horz
• count.opaque
• Cloud amount, thin (percent)(percent.thin)
• count.thin
• region.horizon.count.opaque
• region.sun.count
• region.horizon.count.thin
• count.unknown
• region.horizon.count
• region.sun.count.thin
• region.zenith.count
• region.zenith.count.thin
• Sunshine Meter(sunny)
• sun.strength
• region.sun.count.opaque
• count.box
• count.sky
• count.mask
• Cloud amount, opaque (percent)(percent.opaque)

• Cloud decision images, Total Sky Imager, PNG format(png)

• JPEG data stream - documentation not yet available

NSA/TSI/C1 - shadowband misaligned

At several times during this period the shadowband did not mask the sun because the mirror 
was not properly secured. Attempts were made to align the mirror on 4/2, 4/3, and 4/10.

• region.zenith.count.opaque
• count.sub.horz
• count.sub.proczen
• count.opaque
• Cloud amount, thin (percent)(percent.thin)
• count.thin
• region.horizon.count.opaque
• region.sun.count
• region.horizon.count.thin
• count.unknown
• region.horizon.count
• region.sun.count.thin
• region.zenith.count
• region.zenith.count.thin
• sun.strength
• region.sun.count.opaque
• count.box
• count.sky
• count.mask
• Cloud amount, opaque (percent)(percent.opaque)

• Cloud decision images, Total Sky Imager, PNG format(png)

• JPEG data stream - documentation not yet available

NSA/MPL/C1 - Bad Cross-Polarized data

The polarizer box was not recycled when the system was rebooted; thus only circularly 
polarized light was being emitted.  Ignore all cross polarized data.

• Attenuated backscatter, cross pol(signal_return_cross_pol)
• background_signal_cross_pol
• aqc_signal_return_cross_pol
• Preliminary cloud base height above ground level, cross-pol(preliminary_cbh_cross_pol)
• background_signal_std_cross_pol
• polarization_control_voltage_cross_pol

• polarization_control_voltage
• signal_return

• Attenuated backscatter, cross pol(signal_return_cross_pol)
• polarization_control_voltage_cross_pol
• aqc_signal_return_cross_pol
• background_signal_std_cross_pol
• background_signal_cross_pol
• Preliminary cloud base height above ground level, cross-pol(preliminary_cbh_cross_pol)

NSA/MPL/C1/C2 - No cross polarization data

Even though the polarization voltage was reported as switching between circular and cross 
polarization states, there was no cross polarization taking place because the 
polarization box had not been recycled following a system reboot.

You will not be able to create depolarization values.  However all other processes, such 
as cloud base determination should be ok.

• Attenuated backscatter, cross pol(signal_return_cross_pol)
• background_signal_cross_pol
• aqc_signal_return_cross_pol
• Preliminary cloud base height above ground level, cross-pol(preliminary_cbh_cross_pol)
• background_signal_std_cross_pol
• polarization_control_voltage_cross_pol

• polarization_control_voltage
• signal_return

• Attenuated backscatter, cross pol(signal_return_cross_pol)
• polarization_control_voltage_cross_pol
• aqc_signal_return_cross_pol
• nsamples_cross_pol_average
• background_signal_std_cross_pol
• background_signal_cross_pol
• Preliminary cloud base height above ground level, cross-pol(preliminary_cbh_cross_pol)

NSA/TSI/C1 - frost/condensation in lens

The sky image appeared hazy and was corrected by cleaning the neutral-density filter and 
lens of the camera. The determination of cloud fraction may be affected.

• Cloud amount, thin (percent)(percent.thin)
• Cloud amount, opaque (percent)(percent.opaque)

• JPEG data stream - documentation not yet available

NSA/TSI/C1 - Mirror frozen

The mirror was not rotating so the shadowband was not masking the sun. This appears to 
have been caused by snow that was melted by the mirror heater and then re-frozen by high, 
cold winds.

• region.zenith.count.opaque
• count.opaque
• Cloud amount, thin (percent)(percent.thin)
• count.thin
• region.horizon.count.opaque
• region.sun.count
• region.horizon.count.thin
• region.horizon.count
• region.zenith.count
• region.sun.count.thin
• region.zenith.count.thin
• region.sun.count.opaque
• count.sky
• Cloud amount, opaque (percent)(percent.opaque)

• Cloud decision images, Total Sky Imager, PNG format(png)

• JPEG data stream - documentation not yet available

NSA/MET/C1 - Temp/RH/wind data questionable

New wind sensors and new T/RH probes were being installed during this time period.  The 
tower booms were lowered and much of the data collected were not at listed heights nor were 
the data accurate due to configurations during install.

• qc_wspd_arith_mean
• qc_rh_mean
• qc_wspd_vec_mean
• vapor_pressure_std
• Wind speed vector mean(wspd_vec_mean)
• qc_temp_mean
• temp_std
• Relative humidity mean(rh_mean)
• dew_point_mean
• Wind speed arithmetic mean(wspd_arith_mean)
• Wind direction vector mean(wdir_vec_mean)
• qc_wdir_vec_mean
• Temperature mean(temp_mean)
• vapor_pressure_mean
• wdir_vec_std
• qc_vapor_pressure_mean
• qc_dew_point_mean
• trh_err_code
• dew_point_std
• rh_std

• wdir_vec_std
• qc_wspd_arith_mean
• qc_temp_mean
• trh_err_code
• Wind speed arithmetic mean(wspd_arith_mean)
• qc_wdir_vec_mean
• dew_point_mean
• Temperature mean(temp_mean)
• temp_std
• Wind speed vector mean(wspd_vec_mean)
• Relative humidity mean(rh_mean)
• dew_point_std
• rh_std
• qc_rh_mean
• Wind direction vector mean(wdir_vec_mean)
• vapor_pressure_mean
• vapor_pressure_std
• qc_wspd_vec_mean
• qc_dew_point_mean
• qc_vapor_pressure_mean

NSA/MET/C1 - PWS data missing due to snow impaction

Blizzard conditions caused the optics to become impacted with snow and ice rendering the 
Present Weather Detector inoperative.

• qc_pws_cumul_snow
• qc_pws_pw_code_15min
• qc_pws_precip_rate_mean_1min
• qc_pws_cumul_rain
• PWS 10 minute mean visibility(pws_vis_mean_10min)
• pws_err_code
• qc_pws_vis_mean_1min
• pws_cumul_rain
• pws_pw_code_1hr
• Rain, surface, 1-min avg(pws_precip_rate_mean_1min)
• pws_cumul_snow
• pws_pw_code_15min
• qc_pws_pw_code_inst
• pws_pw_code_inst
• qc_pws_pw_code_1hr
• qc_pws_err_code
• qc_pws_vis_mean_10min
• PWS 1 minute mean visibility(pws_vis_mean_1min)

NSA/MET/C1 - Wind data intermittent

There was a loose wire on the serial data multiplexer causing the wind data to become 
missing during high wind situations.  The high winds caused the enclosure to vibrate making 
the connection intermittent.

• Wind speed arithmetic mean(wspd_arith_mean)
• qc_wspd_arith_mean
• qc_wspd_vec_mean
• Wind direction vector mean(wdir_vec_mean)
• qc_wdir_vec_mean
• Wind speed vector mean(wspd_vec_mean)
• wdir_vec_std

• wdir_vec_std
• qc_wspd_arith_mean
• Wind direction vector mean(wdir_vec_mean)
• qc_wspd_vec_mean
• Wind speed arithmetic mean(wspd_arith_mean)
• qc_wdir_vec_mean
• Wind speed vector mean(wspd_vec_mean)

NSA/MET/C1 - CMH data missing

The data from the CMH was missing during these times due to a failing logic board.  The 
board was replaced.

• cmh_dew_point
• qc_cmh_dew_point
• qc_cmh_rh
• cmh_temp
• cmh_vapor_pressure
• qc_cmh_vapor_pressure
• qc_cmh_sat_vapor_pressure
• qc_cmh_temp
• cmh_sat_vapor_pressure
• cmh_rh

NSA/MET/C1 - Met data incorrect during calibration

All met data from the tower booms (temp, RH, winds and derived variables) were incorrect 
due to the booms being lowered from their measurement heights.  Additionally, the 
scaffolding was located directly adjacent to the booms affecting the wind field and the Temp/RH 
data.

• qc_wspd_arith_mean
• qc_rh_mean
• qc_wspd_vec_mean
• vapor_pressure_std
• Wind speed vector mean(wspd_vec_mean)
• qc_temp_mean
• temp_std
• qc_time
• Relative humidity mean(rh_mean)
• dew_point_mean
• Wind speed arithmetic mean(wspd_arith_mean)
• Wind direction vector mean(wdir_vec_mean)
• qc_wdir_vec_mean
• Temperature mean(temp_mean)
• vapor_pressure_mean
• wdir_vec_std
• qc_vapor_pressure_mean
• qc_dew_point_mean
• trh_err_code
• dew_point_std
• rh_std

• wdir_vec_std
• qc_wspd_arith_mean
• qc_temp_mean
• trh_err_code
• Wind speed arithmetic mean(wspd_arith_mean)
• qc_wdir_vec_mean
• dew_point_mean
• Temperature mean(temp_mean)
• temp_std
• Wind speed vector mean(wspd_vec_mean)
• Relative humidity mean(rh_mean)
• dew_point_std
• rh_std
• qc_rh_mean
• Wind direction vector mean(wdir_vec_mean)
• vapor_pressure_mean
• vapor_pressure_std
• qc_wspd_vec_mean
• qc_dew_point_mean
• qc_vapor_pressure_mean

NSA/MET/C1 - PWS calibration

The PWS was undergoing calibration. Any data collected during this time is not 
representative of the atmospheric state.

• qc_pws_cumul_snow
• qc_pws_pw_code_15min
• qc_pws_precip_rate_mean_1min
• qc_pws_cumul_rain
• PWS 10 minute mean visibility(pws_vis_mean_10min)
• pws_err_code
• qc_pws_vis_mean_1min
• pws_cumul_rain
• pws_pw_code_1hr
• Rain, surface, 1-min avg(pws_precip_rate_mean_1min)
• pws_cumul_snow
• pws_pw_code_15min
• qc_pws_pw_code_inst
• pws_pw_code_inst
• qc_pws_pw_code_1hr
• qc_pws_err_code
• qc_pws_vis_mean_10min
• PWS 1 minute mean visibility(pws_vis_mean_1min)

NSA/MET/C1 - CMH calibration

CMH data missing due to removal of the sensor for annual calibration.

• cmh_dew_point
• qc_cmh_dew_point
• qc_cmh_rh
• cmh_temp
• cmh_vapor_pressure
• qc_cmh_vapor_pressure
• qc_cmh_sat_vapor_pressure
• qc_cmh_temp
• cmh_sat_vapor_pressure
• cmh_rh

NSA/MET/C1 - 2m RH values incorrect

The new t/rh probe installed during annual calibrations and checks began to exhibit 
readings that were biased high compared to the Chilled Mirror Hygrometer.  In high RH 
conditions the sensor would consistently report RH values in excess of 105%.  Comparisons to the 
other tower levels also suggested that the 2m level RH data is suspect.

• Relative humidity mean(rh_mean)
• dew_point_mean
• qc_rh_mean
• vapor_pressure_std
• vapor_pressure_mean
• qc_dew_point_mean
• dew_point_std
• rh_std

• rh_std
• qc_rh_mean
• vapor_pressure_mean
• vapor_pressure_std
• dew_point_mean
• qc_dew_point_mean
• Relative humidity mean(rh_mean)
• dew_point_std
• qc_vapor_pressure_mean

NSA/ARSCL/C1 - Reflectivity values unreliable

Reflectivity dBZ values should not be used.  The reported cloud boundaries may 
underestimate cloud tops, particularly for high or thick clouds.  Also thin high clouds may have 
been missed entirely, especially if there were lower-level cloud layers below them. During 
this time period, the MMCR was transmitting in  circular polarization, rather than 
(correct) linear polarization. This caused reported Reflectivity values to be too low by an 
unknown amount, resulting in an effective loss of radar sensitivity.

Areas identified as have having hydrometeor detections are correct, however some areas 
marked as clear may in fact contain cloud due to the MMCR's low sensitivity during this time.

• Cloud, reflectivity, at altitude(Reflectivity)

• Cloud, reflectivity, at altitude(Reflectivity)

• Cloud, reflectivity, at altitude(Reflectivity)

• Cloud, reflectivity, at altitude(Reflectivity)

• CloudLayerBottomHeightMplCloth
• CloudLayerTopHeightMplCloth

• CloudLayerTopHeightMplCloth
• MMCR Reflectivity, Best estimate, Hydrometer(ReflectivityBestEstimate)
• RadarFirstTop
• Cloud, reflectivity, at altitude(Reflectivity)
• MMCR Reflectivity, clutter removed(ReflectivityNoClutter)
• CloudLayerBottomHeightMplCloth