NSA/METTWR/C1 - Chilled Mirror transmit logic board chipset unsuited for Arctic 
temperatures

Data missing due to problems with manufacturer's transmit logic board chipset.  They were 
generic chips not rated for Arctic temperatures.

• Chilled Mirror Calculated Relative Humidity(CMHRH)
• Chilled Mirror Dew Point(CMHDP)
• Chilled Mirror Temperature(CMHTemp)
• Chilled Mirror Calculated Saturation Vapor Pressure(SatVPCMH)

NSA/METTWR/C1 - Incorrect Maximum for Precip Values

The max values for cumulative rain sum of 99 mm and the rain rate of 999 mm/hr are 
incorrect.  In communication with the manufacturer it has been found that the manual was in 
error.  The actual max values of the cumulative rain sum is 99.99 mm and the rain rate is 
999.99 mm/hr.

• Precipitation Rate(PcpRate)
• Cumulative Water Sum(CumH2O)

NSA/METTWR/C1 - Data 1-minute behind

Data from the Barometer, Chilled Mirror Hygrometer and the Present Weather Sensor were 
one-minute behind due to timing problems collecting data from the Serial Data Multiplexer 
that handled these sensors.

• 15 minute Present Weather Code(PwCod15mi)
• 1 minute Average Visibility(AvgVis1mi)
• Chilled Mirror Dew Point(CMHDP)
• Instant Present Weather Code(InstPwCod)
• Chilled Mirror Calculated Saturation Vapor Pressure(SatVPCMH)
• Chilled Mirror Calculated Relative Humidity(CMHRH)
• Chilled Mirror Calculated Vapor Pressure(VPCMH)
• 1 hour Present Weather Code(PwCod1hr)
• Cumulative Snow Sum(CumSnow)
• 10 minute Average Visibility(AvgVis10m)
• Chilled Mirror Temperature(CMHTemp)
• Precipitation Rate(PcpRate)
• Cumulative Water Sum(CumH2O)
• Present Weather Sensor Alarm(PWSAlarm)
• Atmospheric Pressure(AtmPress)

NSA/METTWR/C1 - Reprocess: Wind direction data incorrect

Wind direction data is off by 30 degrees for all wind sensors.  The 40-m tower was 
misaligned to true north.

• 40m Vector Averaged Wind Direction(WD40M_DU_WVT)
• 2m Vector Averaged Wind Direction(WD2M_DU_WVT)
• 20m Vector Averaged Wind Direction(WD20M_DU_WVT)
• Sonic Vector Averaged Wind Direction(SonicWD_DU_WVT)
• 10m Vector Averaged Wind Direction(WD10M_DU_WVT)

NSA/METTWR/C1 - Reprocess: Barometric Data Changed from hPa to kPa

Barometric pressure data was converted from hPa to kPa in order to standardize the 
measurement units among ARM sites and to conform to accepted standard units determined by the 
scientific community.

• Atmospheric Pressure(AtmPress)

NSA/SONDE/C1 - Increased precision for alt, dp, pres, rh, tdry

The output precision of the following variables was increased 20060929:

   alt	changed from 1m to 0.1m
   dp	changed from 0.1degC to 0.01degC
   pres changed from 0.1 hPa to 0.01 hPa
   RH	changed from 1%RH to 0.01%RH
   tdry changed from .1degC to 0.01degC

Note that the increase in precision does not necessarily imply an increase
in accuracy.  Users are cautioned to continue to use their best scientific
judgement when using these or any other data.

• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• altitude above sea levelaltunits(alt)
• pressure at constant pressure surface(pres)
• Surface dew point temperature(dp)