Data Quality Reports for Session: 129758 User: jzb Completed: 08/13/2010

TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D060803.1NSA/MMCR/C1 - Sensitivity Loss, Calibration WrongnsammcrmomC1.00, nsammcrmomC1.b1, nsammcrspecmomC1.a0
D061211.1NSA/MMCR/C1 - MMCR TWTA FailurensammcrmomC1.00, nsammcrmomC1.b1, nsammcrspecmomC1.a0
D070716.4NSA/MMCR/C1 - Antenna Feed CorrosionnsammcrmomC1.b1, nsammcrspecmomC1.a0


DQRID : D060803.1
Start DateStart TimeEnd DateEnd Time
08/01/2005000002/01/20072359
Subject:
NSA/MMCR/C1 - Sensitivity Loss, Calibration Wrong
DataStreams:nsammcrmomC1.00, nsammcrmomC1.b1, nsammcrspecmomC1.a0
Description:
Jay Mace compared data from CLOUDSAT to the MMCR and found significant discrepancies.  It 
appears that the MMCR has a sensitivity problem and is underreporting reflectivity by ~20 
dBZ.  A comparison with the MPL shows that this might be a gradual degradation, i.e. 
there are no apparent shifts identifying when this might have occured.
Measurements:nsammcrmomC1.b1:
  • Time associated with hourly averaged values(TimeAvg)
  • Data Quality Status(DataQualityStatus)
  • Delay to First Range Gate(StartGateDelay)
  • Number of Spectral Averages(NumSpectralAverages)
  • Receiver Sky Noise(SkyNoiseLevel)
  • Range Corrected Calibrated Power(RangeCorrectedPower)
  • base time(base_time)
  • Time offset of tweaks from base_time(time_offset)
  • Radar Constant(RadarConstant)
  • Inter-Pulse Period(InterPulsePeriod)
  • lat(lat)
  • Dummy altitude for Zeb(alt)
  • MMCR Mean Doppler Velocity(MeanDopplerVelocity)
  • Number of Code Bits(NumCodeBits)
  • Peak tranmitted power, averaged over the course of the hour(PeakTransmittedPowerAvg)
  • RadarWaveLength(m) / [4 * InterPulsePeriod(s) * NumCoherentIntegrations](NyquistVelocity)
  • Current Receiver Number(ReceiverNumber)
  • MMCR Spectral Width(SpectralWidth)
  • MMCR Reflectivity(Reflectivity)
  • Number of Gate Heights(NumHeights)
  • Array of heights for each power(heights)
  • TWT Status Code, details forthcoming from MMCR vendor(TWTStatusCode)
  • Power (uncalibrated)(Power)
  • Number of Points in FFT(NumFFT)
  • Receiver Mode(ReceiverMode)
  • Average Noise Level (S/N<0)(AvgNoiseLevel)
  • Receiver Gain(RxGain)
  • Mean Noise Level(NoiseLevel)
  • Signal to Noise Ratio(SignalToNoiseRatio)
  • Receiver 290K Level(Rx290KLevel)
  • Max. height of clutter removal(ClutterHeight)
  • DC Filtering ON-OFF Status(DCFilterONOFF)
  • Receiver Cal Check Time Stamp(CalCheckTime)
  • Windowing ON-OFF Status(WindowingONOFF)
  • lon(lon)
  • radar mode char identifier(ModeDescription)
  • time(time)
  • Receiver Cal Time Stamp(RxCalTimeStamp)
  • Receiver Cal Check Level(CalCheckLevel)
  • Number of Receiver(NumReceivers)
  • Circular Depolarization Ratio(CircularDepolarizationRatio)
  • Number of Coherent Integrations(NumCoherentIntegrations)
  • Operating Set for this Record(ModeNum)
  • Pulse Width(PulseWidth)
  • Minimum detectable reflectivity(MinimumDetectableReflectivity)
  • Gate Spacing(GateSpacing)
nsammcrspecmomC1.a0:
  • Number of Spectral Averages(NumSpectralAverages)
  • MMCR Mean Doppler Velocity(MeanDopplerVelocity)
  • Delay to First Range Gate(StartGateDelay)
  • Elevation(Elevation)
  • Circular Depolarization Ratio(CircularDepolarizationRatio)
  • Inter-Pulse Period(InterPulsePeriod)
  • Number of Points in FFT(NumFFT)
  • Number of Code Bits(NumCodeBits)
  • Minimum detectable reflectivity(MinimumDetectableReflectivity)
  • Time offset of tweaks from base_time(time_offset)
  • Power (uncalibrated)(Power)
  • Height of Center of Each Range Bin(Heights)
  • Number of Receiver(NumReceivers)
  • Mean Noise Level(NoiseLevel)
  • radar mode char identifier(ModeDescription)
  • Receiver Sky Noise(SkyNoiseLevel)
  • Operating Set for this Record(ModeNum)
  • lon(lon)
  • Receiver Cal Time Stamp(RxCalTimeStamp)
  • Receiver 290K Level(Rx290KLevel)
  • Receiver Cal Check Level(CalCheckLevel)
  • Data Quality Status(DataQualityStatus)
  • Dummy altitude for Zeb(alt)
  • base time(base_time)
  • First Order Estimate of Spectral Count Calibration(CalibrationConstant)
  • Radar Constant(RadarConstant)
  • Signal to Noise Ratio(SignalToNoiseRatio)
  • Current Receiver Number(ReceiverNumber)
  • Receiver Cal Check Time Stamp(CalCheckTime)
  • Number of Gate Heights(NumHeights)
  • Receiver Mode(ReceiverMode)
  • RadarWaveLength(m) / [4 * InterPulsePeriod(s) * NumCoherentIntegrations](NyquistVelocity)
  • Average Noise Level (S/N<0)(AvgNoiseLevel)
  • MMCR Spectral Width(SpectralWidth)
  • Azimuth(Azimuth)
  • Windowing ON-OFF Status(WindowingONOFF)
  • Max. height of clutter removal(ClutterHeight)
  • Pulse Width(PulseWidth)
  • Spectral Data(Spectra)
  • Number of Coherent Integrations(NumCoherentIntegrations)
  • Receiver Gain(RxGain)
  • Range Corrected Calibrated Power(RangeCorrectedPower)
  • MMCR Reflectivity(Reflectivity)
  • DC Filtering ON-OFF Status(DCFilterONOFF)
  • Gate Spacing(GateSpacing)
  • lat(lat)
nsammcrmomC1.00:
  • Raw data stream - documentation not supported(raw)

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DQRID : D061211.1
Start DateStart TimeEnd DateEnd Time
11/05/2005010002/01/20072359
Subject:
NSA/MMCR/C1 - MMCR TWTA Failure
DataStreams:nsammcrmomC1.00, nsammcrmomC1.b1, nsammcrspecmomC1.a0
Description:
The TWTA is no longer transmitting.
Measurements:nsammcrmomC1.b1:
  • Time associated with hourly averaged values(TimeAvg)
  • Data Quality Status(DataQualityStatus)
  • Delay to First Range Gate(StartGateDelay)
  • Number of Spectral Averages(NumSpectralAverages)
  • Receiver Sky Noise(SkyNoiseLevel)
  • Range Corrected Calibrated Power(RangeCorrectedPower)
  • base time(base_time)
  • Time offset of tweaks from base_time(time_offset)
  • Radar Constant(RadarConstant)
  • Inter-Pulse Period(InterPulsePeriod)
  • lat(lat)
  • Dummy altitude for Zeb(alt)
  • MMCR Mean Doppler Velocity(MeanDopplerVelocity)
  • Number of Code Bits(NumCodeBits)
  • Peak tranmitted power, averaged over the course of the hour(PeakTransmittedPowerAvg)
  • RadarWaveLength(m) / [4 * InterPulsePeriod(s) * NumCoherentIntegrations](NyquistVelocity)
  • Current Receiver Number(ReceiverNumber)
  • MMCR Spectral Width(SpectralWidth)
  • MMCR Reflectivity(Reflectivity)
  • Number of Gate Heights(NumHeights)
  • Array of heights for each power(heights)
  • TWT Status Code, details forthcoming from MMCR vendor(TWTStatusCode)
  • Power (uncalibrated)(Power)
  • Number of Points in FFT(NumFFT)
  • Receiver Mode(ReceiverMode)
  • Average Noise Level (S/N<0)(AvgNoiseLevel)
  • Receiver Gain(RxGain)
  • Mean Noise Level(NoiseLevel)
  • Signal to Noise Ratio(SignalToNoiseRatio)
  • Receiver 290K Level(Rx290KLevel)
  • Max. height of clutter removal(ClutterHeight)
  • DC Filtering ON-OFF Status(DCFilterONOFF)
  • Receiver Cal Check Time Stamp(CalCheckTime)
  • Windowing ON-OFF Status(WindowingONOFF)
  • lon(lon)
  • radar mode char identifier(ModeDescription)
  • time(time)
  • Receiver Cal Time Stamp(RxCalTimeStamp)
  • Receiver Cal Check Level(CalCheckLevel)
  • Number of Receiver(NumReceivers)
  • Circular Depolarization Ratio(CircularDepolarizationRatio)
  • Number of Coherent Integrations(NumCoherentIntegrations)
  • Operating Set for this Record(ModeNum)
  • Pulse Width(PulseWidth)
  • Minimum detectable reflectivity(MinimumDetectableReflectivity)
  • Gate Spacing(GateSpacing)
nsammcrspecmomC1.a0:
  • Number of Spectral Averages(NumSpectralAverages)
  • MMCR Mean Doppler Velocity(MeanDopplerVelocity)
  • Delay to First Range Gate(StartGateDelay)
  • Elevation(Elevation)
  • Circular Depolarization Ratio(CircularDepolarizationRatio)
  • Inter-Pulse Period(InterPulsePeriod)
  • Number of Points in FFT(NumFFT)
  • Number of Code Bits(NumCodeBits)
  • Minimum detectable reflectivity(MinimumDetectableReflectivity)
  • Time offset of tweaks from base_time(time_offset)
  • Power (uncalibrated)(Power)
  • Height of Center of Each Range Bin(Heights)
  • Number of Receiver(NumReceivers)
  • Mean Noise Level(NoiseLevel)
  • radar mode char identifier(ModeDescription)
  • Receiver Sky Noise(SkyNoiseLevel)
  • Operating Set for this Record(ModeNum)
  • lon(lon)
  • Receiver Cal Time Stamp(RxCalTimeStamp)
  • Receiver 290K Level(Rx290KLevel)
  • Receiver Cal Check Level(CalCheckLevel)
  • Data Quality Status(DataQualityStatus)
  • Dummy altitude for Zeb(alt)
  • base time(base_time)
  • First Order Estimate of Spectral Count Calibration(CalibrationConstant)
  • Radar Constant(RadarConstant)
  • Signal to Noise Ratio(SignalToNoiseRatio)
  • Current Receiver Number(ReceiverNumber)
  • Receiver Cal Check Time Stamp(CalCheckTime)
  • Number of Gate Heights(NumHeights)
  • Receiver Mode(ReceiverMode)
  • RadarWaveLength(m) / [4 * InterPulsePeriod(s) * NumCoherentIntegrations](NyquistVelocity)
  • Average Noise Level (S/N<0)(AvgNoiseLevel)
  • MMCR Spectral Width(SpectralWidth)
  • Azimuth(Azimuth)
  • Windowing ON-OFF Status(WindowingONOFF)
  • Max. height of clutter removal(ClutterHeight)
  • Pulse Width(PulseWidth)
  • Spectral Data(Spectra)
  • Number of Coherent Integrations(NumCoherentIntegrations)
  • Receiver Gain(RxGain)
  • Range Corrected Calibrated Power(RangeCorrectedPower)
  • MMCR Reflectivity(Reflectivity)
  • DC Filtering ON-OFF Status(DCFilterONOFF)
  • Gate Spacing(GateSpacing)
  • lat(lat)
nsammcrmomC1.00:
  • Raw data stream - documentation not supported(raw)

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DQRID : D070716.4
Start DateStart TimeEnd DateEnd Time
01/01/2006000010/17/20070200
Subject:
NSA/MMCR/C1 - Antenna Feed Corrosion
DataStreams:nsammcrmomC1.b1, nsammcrspecmomC1.a0
Description:
During a trip to Barrow, I inspected the feed under the antenna and noticed an extreme 
amount of corrosion that has resulted in the flexible waveguide connected to the feed to be 
pushed off at an angle with corrosion in between.  I attempted to remove and clean but 
the corrosion has effectively welded the two pieces together.

This didn't happen overnight and the start date is a guess.  The last inspection of the 
antenna probably took place in April 2004 when we did the C40 DSP upgrade.  I don't know 
how much the reflectivity is affected by this corrosion.  It may be possible to get an idea 
once we replace the antenna by making some intercomparison measurements.

The feed was temporarily repaired on 10/16/2007 until the new antenna was installed.  The 
measured loss before and after the repair was 5.1 dB.  This means that the MMCR was 
under-reporting reflectivity by 10.2 dB just before it was repaired.  That said, there is no 
way of ascertaining what the rate of corrosion was and how the loss changed during the 
period of this DQR.  One can assume that the 5.1 dB loss was the worst that it was.
Measurements:nsammcrmomC1.b1:
  • Power (uncalibrated)(Power)
  • Radar Constant(RadarConstant)
  • MMCR Reflectivity(Reflectivity)
  • Range Corrected Calibrated Power(RangeCorrectedPower)
nsammcrspecmomC1.a0:
  • Range Corrected Calibrated Power(RangeCorrectedPower)
  • MMCR Reflectivity(Reflectivity)
  • Radar Constant(RadarConstant)
  • Signal to Noise Ratio(SignalToNoiseRatio)
  • Power (uncalibrated)(Power)

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