NIM/MET/M1 - Software problem

Intermittent Failure of Logger to read data from the Barometer.

• Atmospheric pressure(atmos_pressure)

NIM/MET/M1  - ORG failure

The optical rain gauge on the met system did not record precipitation during this time 
period.

• ORG precipitation rate mean(org_precip_rate_mean)

NIM/MET/M1 - ORG underestimated precipitation

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

• ORG precipitation rate mean(org_precip_rate_mean)

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 vector mean(wspd_vec_mean)
• Wind speed, lower, 1-min avg(wspd_arith_mean)

NIM/MET/M1 - PWD cumulative precipitation incorrect

The Present Weather Detector is a serial sensor.  The MET system datalogger reads in the 
data from this sensor.  During the time in question serial comms problems were causing the 
data from the sensor to be read incorrectly.  The data for one variable showed up in 
data for another variable or not at all.  We reprocessed the data to correct as much of this 
error as we could.  The cumulative rainfall variable was calculated from the 
instantaneous rainfall variable during reprocessing.  Since we cannot be entirely sure all 
cumulative rainfall values are correct or were completely captured the cumulative rainfall data is 
considered to be unreliable.  This issue shows up when comparing the cumulative rainfall 
data at the end of the day 07/31/2006 (79.08) and the beginning of the next day 
08/01/2006 (3.17).  Clearly we were either under or over-estimating the cumulative rainfall.

• pwd_cumul_rain

NIM/MET/M1 - PWD 1 minute rainfall data suspect

The Present Weather Detector is a serial sensor.  The MET system datalogger reads in the 
data from this sensor.  During the time in question serial comms problems were causing the 
data from the sensor to be read incorrectly.  The data for one variable showed up in 
data for another variable or not at all.  We reprocessed the data to correct as much of this 
error as we could. We cannot be entirely certain that all rainfall values are correct or 
were captured properly.  It is possible that some values were missed completely.

• PWD 1 minute mean precipitation rate(pwd_precip_rate_mean_1min)

NIM/MET/M1 - Deployment period

All data from the met tower are suspect during this time period as the systems were being 
deployed and in various states of operation.

• ORG precipitation rate mean(org_precip_rate_mean)
• time
• Humidity, relative, at 2-m height, 1-min avg(rh_mean)
• logger_temp
• PWD 10 minute mean visibility(pwd_mean_vis_10min)
• PWD 1 minute mean precipitation rate(pwd_precip_rate_mean_1min)
• Temperature mean(temp_mean)
• pwd_err_code
• Atmospheric pressure(atmos_pressure)
• pwd_cumul_rain
• Wind direction vector mean(wdir_vec_mean)
• Vapor pressure mean, calculated(vapor_pressure_mean)
• vapor_pressure_std
• rh_std
• PWD 1 minute mean visibility(pwd_mean_vis_1min)
• temp_std
• Wind speed, lower, 1-min avg(wspd_arith_mean)
• Altitude above mean sea level(alt)
• time_offset
• pwd_pw_code_inst
• logger_volt
• North latitude(lat)
• East longitude(lon)
• base_time
• pwd_pw_code_1hr
• pwd_pw_code_15min
• Wind speed vector mean(wspd_vec_mean)
• wdir_vec_std