SGP/ARSCL/C1 - ARSCL Cloud Bases and Low-level reflectivities

Prior to February 4, 2000, the ARSCL data set incorporated data from the
Beaufort Laser Ceilometer as one of its inputs.  Because of the BLC's
high spatial resolution, this data was often chosen by ARSCL as the
"CloudBaseBestEstimate" for boundary layer clouds. It was subsequently
determined that the BLC cloud base was biased, with the BLC reporting
cloud base heights that are 122 meters too high.

The bias error will be corrected when the entire ARSCL data set is
reprocessed as part of release_4.  (The release version number is included
the the netCDF global comments).   This reprocessing will also include a
small correction the the MMCR near-field reflectivities.  This correction
is less than 1 dB except for hydrometers within 200 meters of the surface.

Thanks to Roger Marchand for helping bracket this problem.

• Reflectivity(Reflectivity)
• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• MMCR Reflectivity, Best estimate, Hydrometer(ReflectivityBestEstimate)
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)
• CloudBase, Best estimate(CloudBaseBestEstimate)

• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)

SGP/MPL/C1 - Reduced detection sensitivity

During the time periods indicated, the laser power supply was low.  This resulted in 
compromised detection sensitivity, particularly for thin clouds and/or during daylight hours.  
That is, some clouds may not have been identified.  The low laser power would not have 
resulted in false positives.

• MPL Cloth et al. Algorithm Significance Mask(SigniMaskMplCloth)

• MPL Cloth et al. Algorithm Cloud Mask(CloudMaskMplCloth)

SGP/MMCR/C1 - Power supply failure

A power supply failed in the MMCR's receiver.  During the period of this DQR, the radar 
would appear to work but the calibration is probably incoorect during good portions of this 
time.  The power supply was replaced and normal operation resumed at 2115 on 02/11/2005.

• MMCR Mean Doppler Velocity(MeanDopplerVelocity)
• MPL Cloth et al. Algorithm Cloud Mask(CloudMaskMplCloth)
• MPL Campbell et al. Algorithm Cloud Base Height(CloudBaseMplCamp)
• MMCR Spectral Width(SpectralWidth)
• MMCR Reflectivity, clutter removed(ReflectivityNoClutter)
• CloudLayerBottomHeightMplCloth
• time_offset
• CloudLayerTopHeightMplCamp
• MMCR Reflectivity, Best estimate, Hydrometer(ReflectivityBestEstimate)
• SignaltoNoiseRatio
• MPL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseMplCloth)
• Heights
• CloudBase, Best estimate(CloudBaseBestEstimate)
• CloudLayerTopHeightMplCloth
• CloudLayerBottomHeightMplCamp
• Reflectivity(Reflectivity)
• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• base_time
• CloudBasePrecipitation
• ModeId
• RadarFirstTop
• Cloud Mask Occurrence, MPL Campbell et al. algorithm(CloudMaskMplCamp)
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)
• MPL Scott Algorithm Cloud Base Height(CloudBaseMplScott)

SGP/MPL/C1 - Instrument offline

Instrument was taken offline due to a failure of the laser power supply.  Data are missing 
and unrecoverable.

• MPL Cloth et al. Algorithm Significance Mask(SigniMaskMplCloth)
• base_time
• Heights
• time_offset

• time_offset
• base_time
• Heights
• MPL Cloth et al. Algorithm Cloud Mask(CloudMaskMplCloth)

SGP/ARSCL/C1 - Ceilometer not used during processing

The ceilometer was not used during processing due to a ceilometer data format change that 
ARSCL did not handle properly.  As a result, cloud boundaries in the lowest several 
kilometers may be less accurate than usual, as they are based solely on the micropulse lidar 
and millimeter cloud radar.

• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)
• CloudBase, Best estimate(CloudBaseBestEstimate)

• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)