NIM/MWRP/M1 - Instrument noise problem

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.

• Raw data stream - documentation not supported(raw)

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

• Raw data stream - documentation not supported(raw)

NIM/MWRP/M1 - 51.25 GHz channel calibration drifted

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).

• Microwave brightness temperature(brightnessTemperature)

NIM/RWP/M1 - Reprocess: Wind direction offset

A strong wind storm on June 17, 2006 toppled the RWP antenna.  After repair and 
reinstallation, the wind direction reported by the instrument was rotated counterclockwise 90 
degrees, possibly because the antenna was installed rotated by 90 deg.  This condition 
continued through the remainder of deployment.

All wind direction values need to be increased by 90 degrees.

• U-component(u_wind)
• V-component(v_wind)

NIM/MET/M1 - ORG Data Underestimated Precipitation

The ORG underestimated precipitation by about 38% during the entire NIM deployment.  No 
troubleshooting technique or replacement of gage was successful in correcting the problem.

• Precipitation rate minimum(precip_rate_min)
• ORG carrier mean(org_carrier_mean)
• Precipitation rate mean(precip_rate_mean)
• Precipitation rate maximum(precip_rate_max)
• Precipitation rate standard deviation(precip_rate_sd)

NIM/MET/M1 - Reprocess: ORG Data has very small rainrate values

The ORG data is collected via analog signal and not digital.  Therefore, we
   continuously collect data even when no rain is occurring.  We also capture
   small events such as leaves, large bugs, dust, etc blowing through the
   measurement path.  Because this discrete event occurs quickly the value is
   usually captured for 1 or 2 seconds.  This value is then averaged to the
   minute producing rainrate on the order of .009 mm/hr or less.  These values
   are not indicative of rain and should be removed from the record or summing
   over long periods can bias the climate record.  We are reprocessing the data
   to remove these small values and are adjusting the collection program to
   remove them before ingest.

• Precipitation rate minimum(precip_rate_min)
• Precipitation rate mean(precip_rate_mean)
• Precipitation rate maximum(precip_rate_max)
• Precipitation rate standard deviation(precip_rate_sd)

NIM/MET/M1 - Wind Speed data contain offset due to induced voltage

The marine model of the RM Young wind sensor needs twisted pair shielded cable.  The 
manufacturer did not originally supply the pigtail with twisted pair shielded cable.  Use of 
twisted pair shielded cable for the rest of the cable run to the logger was also not 
specified.  This caused an induced voltage in the wind speed line from the wind direction 
excitation.  The induced voltage varied from sensor to sensor and probably changed anytime 
the cable was replaced or parts of the wind sensor were repaired or replaced. The induced 
voltage has been seen to vary from 0.15 m/s to as much as 1.08 m/s.

• Wind speed arithmetic average(wind_spd_arith_avg)
• Vector-averaged Wind Speed(wind_spd_vec_avg)
• Wind speed arithmetic minimum(wind_spd_arith_min)
• Wind speed arithmetic maximum(wind_spd_arith_max)
• Wind speed arithmetic standard deviation(wind_spd_arith_sd)