Data Quality Reports for Session: 107612 User: hansell Completed: 09/07/2007


TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D060419.3NIM/MWRP/M1 - Instrument noise problemnimmwrpM1.00, nimmwrpM1.b1, nimmwrprawM1.00
D060619.1NIM/MWRP/M1 - Reprocessed - New retrieval coefficientsnimmwrpM1.b1
D060713.1NIM/MWRP/M1 - 51.25 GHz channel calibration driftednimmwrpM1.b1
D060929.1NIM/MWRP/M1 - Sun in radiometer's field of viewnimmwrpM1.b1


DQRID : D060419.3
Start DateStart TimeEnd DateEnd Time
01/01/2006000001/08/20070000
Subject:
NIM/MWRP/M1 - Instrument noise problem
DataStreams:nimmwrpM1.00, nimmwrpM1.b1, nimmwrprawM1.00
Description:
There are spikes and elevated noise in MWRP data. The origine of the spikes is RF 
interference from various sources.  All brightness temperatures are affected, but in particular 
the 5 K-band channels. LWP retrievals are noisy and affected by spikes as a result.
Measurements:nimmwrprawM1.00:
  • Raw data stream - documentation not supported(raw)

nimmwrpM1.b1:
  • Retrieved cloud liquid water content(liquidWaterContent)
  • Derived relative humidity(relativeHumidity)
  • Derived virtual temperature(virtualTemperature)
  • Interpolated water vapor mixing ratio(waterVaporMixingRatio)
  • Retrieved liquid water path using only 23.835 and 30.0 GHz(liquidWaterPath2)
  • air temperature (NGM250 predicted)(temperature)
  • Retrieved water vapor density(waterVaporDensity)
  • Interpolated dewpoint temperature(dewpointTemperature)
  • Retrieved liquid water path(liquidWaterPath)
  • Retrieved total precipitable water vapor using only 23.835 and 30.0 GHz(totalPrecipitableWater2)
  • Microwave brightness temperature(brightnessTemperature)
  • Total precipitable water vapor, from microwave radiometer(totalPrecipitableWater)

nimmwrpM1.00:
  • Raw data stream - documentation not supported(raw)


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DQRID : D060619.1
Start DateStart TimeEnd DateEnd Time
01/01/2006000008/24/20062300
Subject:
NIM/MWRP/M1 - Reprocessed - New retrieval coefficients
DataStreams:nimmwrpM1.b1
Description:
Occasionally, the retrieved relative humidity was exceeding 120%. Upon reviewing the data 
it was noticed that the high values were appearing in the highest layers (above 8 km) and 
especially during spring season. Since retrievals at the highest levels are mainly 
affected by the climatology used to constrain the retrievals, we reviewed the statistical 
coefficients that were used to retrieve temperature and humidity. It was discovered that, in 
the training dataset (radiosonde), there were a few outliers (invalid radiosonde 
soundings) that had escaped the screening process and were affecting the computations of the 
retrieval coefficients.

We recomputed the retrieval coefficients with the newly screened set of radiosonde data 
and reprocessed all the previous data at Niamey.  The reprocessed data were archived in 
August 2006.

The new coefficients improve temperature and humidity profiles in two ways. The relative 
humidity will not exceed 120% in the upper layers and the temperature profiles will be in 
better agreement with the sonde in the first 4 km.
Measurements:nimmwrpM1.b1:
  • Expected root-mean-square error in liquid water path retrieval(liquidWaterPathRmsError)
  • Expected root-mean-square error in liquid water content retrieval(liquidWaterContentRmsError)
  • Expected root-mean-square error in liquid water path retrieval using only 23.835
    and 30.0 GHz(liquidWaterPath2RmsError)
  • Retrieved cloud liquid water content(liquidWaterContent)
  • Derived relative humidity(relativeHumidity)
  • Derived virtual temperature(virtualTemperature)
  • Interpolated water vapor mixing ratio(waterVaporMixingRatio)
  • Expected root-mean-square error in precipitable water retrieval(totalPrecipitableWaterRmsError)
  • Expected root-mean-square error in water vapor density retrieval(waterVaporDensityRmsError)
  • Retrieved liquid water path using only 23.835 and 30.0 GHz(liquidWaterPath2)
  • air temperature (NGM250 predicted)(temperature)
  • Retrieved water vapor density(waterVaporDensity)
  • Interpolated dewpoint temperature(dewpointTemperature)
  • Retrieved liquid water path(liquidWaterPath)
  • Cloud base height(cloudBaseHeight)
  • Retrieved total precipitable water vapor using only 23.835 and 30.0 GHz(totalPrecipitableWater2)
  • Expected root-mean-square error in temperature retrieval(temperatureRmsError)
  • Expected root-mean-square error in precipitable water retrieval using only
    23.835 and 30.0 GHz(totalPrecipitableWater2RmsError)
  • Total precipitable water vapor, from microwave radiometer(totalPrecipitableWater)


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DQRID : D060713.1
Start DateStart TimeEnd DateEnd Time
05/05/2006000001/08/20070000
Subject:
NIM/MWRP/M1 - 51.25 GHz channel calibration drifted
DataStreams:nimmwrpM1.b1
Description:
After a power outage on May 5 the 51.25 GHz had a slight change in the calibration. The 
resulting LWP computed by using all 6 channels increased of about 0.025 mm (25 g/m2).
Measurements:nimmwrpM1.b1:
  • Microwave brightness temperature(brightnessTemperature)


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DQRID : D060929.1
Start DateStart TimeEnd DateEnd Time
08/01/2006000008/31/20062359
Subject:
NIM/MWRP/M1 - Sun in radiometer's field of view
DataStreams:nimmwrpM1.b1
Description:
Around noon local time every day there is a spike in the brightness temperature data. This 
is due to the sun being in the field of view of the radiometer. PWV and LWP are affected 
as a consequence
Measurements:nimmwrpM1.b1:
  • Expected root-mean-square error in precipitable water retrieval(totalPrecipitableWaterRmsError)
  • Expected root-mean-square error in liquid water path retrieval(liquidWaterPathRmsError)
  • Retrieved liquid water path using only 23.835 and 30.0 GHz(liquidWaterPath2)
  • Expected root-mean-square error in liquid water content retrieval(liquidWaterContentRmsError)
  • Zenith-pointing infrared temperature at 10um(infraredTemperature)
  • Retrieved liquid water path(liquidWaterPath)
  • Expected root-mean-square error in liquid water path retrieval using only 23.835
    and 30.0 GHz(liquidWaterPath2RmsError)
  • Retrieved total precipitable water vapor using only 23.835 and 30.0 GHz(totalPrecipitableWater2)
  • Microwave brightness temperature(brightnessTemperature)
  • Retrieved cloud liquid water content(liquidWaterContent)
  • Expected root-mean-square error in precipitable water retrieval using only
    23.835 and 30.0 GHz(totalPrecipitableWater2RmsError)
  • Total precipitable water vapor, from microwave radiometer(totalPrecipitableWater)


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