Subject: | NSA/MMCR/C1 - Sensitivity Loss, Calibration Wrong |
DataStreams: | nsammcrspecmomC1.a0, nsammcrmomC1.00, nsammcrmomC1.b1
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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. |
Suggestions: | Don't use the data until the problem is resolved. |
Measurements: | nsammcrmomC1.b1: - Data Quality Status(DataQualityStatus)
- Minimum detectable reflectivity(MinimumDetectableReflectivity)
- Average Noise Level (S/N<0)(AvgNoiseLevel)
- Number of Points in FFT(NumFFT)
- TWT Status Code, details forthcoming from MMCR vendor(TWTStatusCode)
- Number of Range Gates(NumHeights)
- Circular Depolarization Ratio(CircularDepolarizationRatio)
- Operating Set for this Record(ModeNum)
- Pulse Width(PulseWidth)
- Receiver Cal Check Level(CalCheckLevel)
- Windowing ON-OFF Status(WindowingONOFF)
- Radar Constant(RadarConstant)
- Receiver Mode(ReceiverMode)
- -180.0 - +180.0(alt)
- base time in epoch(base_time)
- North Latitude(lat)
- Reflectivity(Reflectivity)
- radar mode char identifier(ModeDescription)
- Inter-Pulse Period(InterPulsePeriod)
- lon(lon)
- Current Receiver Number(ReceiverNumber)
- DC Filtering ON-OFF Status(DCFilterONOFF)
- Receiver Gain(RxGain)
- Range Corrected Calibrated Power(RangeCorrectedPower)
- Gate Spacing(GateSpacing)
- Delay to First Range Gate(StartGateDelay)
- Number of Spectral Averages(NumSpectralAverages)
- Peak tranmitted power, averaged over the course of the hour(PeakTransmittedPowerAvg)
- Receiver 290K Level(Rx290KLevel)
- MMCR Spectral Width(SpectralWidth)
- Number of Coherent Integrations(NumCoherentIntegrations)
- Mean Noise Level(NoiseLevel)
- Time associated with hourly averaged values(TimeAvg)
- Power (uncalibrated)(Power)
- Time offset from base_time(time_offset)
- Max. height of clutter removal(ClutterHeight)
- Receiver Sky Noise(SkyNoiseLevel)
- Number of Receiver(NumReceivers)
- RadarWaveLength(m) / [4 * InterPulsePeriod(s) * NumCoherentIntegrations](NyquistVelocity)
- Range Heights (center of radar sample volume)(heights)
- time_in_seconds_since_volume_start(time)
- Signal to Noise Ratio(SignalToNoiseRatio)
- MMCR Mean Doppler Velocity(MeanDopplerVelocity)
- Receiver Cal Time Stamp(RxCalTimeStamp)
- Receiver Cal Check Time Stamp(CalCheckTime)
- Number of Code Bits(NumCodeBits)
more
nsammcrspecmomC1.a0: - Data Quality Status(DataQualityStatus)
- Max. height of clutter removal(ClutterHeight)
- Receiver 290K Level(Rx290KLevel)
- Delay to First Range Gate(StartGateDelay)
- Radar Constant(RadarConstant)
- Receiver Cal Check Level(CalCheckLevel)
- Number of Spectral Averages(NumSpectralAverages)
- Range Corrected Calibrated Power(RangeCorrectedPower)
- Signal to Noise Ratio(SignalToNoiseRatio)
- Average Noise Level (S/N<0)(AvgNoiseLevel)
- Number of Code Bits(NumCodeBits)
- Power (uncalibrated)(Power)
- Elevation(Elevation)
- radar mode char identifier(ModeDescription)
- Mean Noise Level(NoiseLevel)
- Circular Depolarization Ratio(CircularDepolarizationRatio)
- base time in epoch(base_time)
- Windowing ON-OFF Status(WindowingONOFF)
- Operating Set for this Record(ModeNum)
- Inter-Pulse Period(InterPulsePeriod)
- First Order Estimate of Spectral Count Calibration(CalibrationConstant)
- Receiver Cal Time Stamp(RxCalTimeStamp)
- Gate Spacing(GateSpacing)
- Reflectivity(Reflectivity)
- Number of Coherent Integrations(NumCoherentIntegrations)
- Number of Points in FFT(NumFFT)
- Receiver Gain(RxGain)
- Minimum detectable reflectivity(MinimumDetectableReflectivity)
- Range Heights (center of radar sample volume)(Heights)
- Time offset from base_time(time_offset)
- RadarWaveLength(m) / [4 * InterPulsePeriod(s) * NumCoherentIntegrations](NyquistVelocity)
- Number of Range Gates(NumHeights)
- MMCR Spectral Width(SpectralWidth)
- Pulse Width(PulseWidth)
- lon(lon)
- DC Filtering ON-OFF Status(DCFilterONOFF)
- Receiver Sky Noise(SkyNoiseLevel)
- Receiver Mode(ReceiverMode)
- MMCR Mean Doppler Velocity(MeanDopplerVelocity)
- North Latitude(lat)
- -180.0 - +180.0(alt)
- Receiver Cal Check Time Stamp(CalCheckTime)
- Number of Receiver(NumReceivers)
- Current Receiver Number(ReceiverNumber)
- Azimuth(Azimuth)
- Spectra(Spectra)
more
nsammcrmomC1.00: - (Raw data stream - documentation not supported)
more
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