NIM/SKYRAD/M1 - IRTs do not agree with AERI

Since deployment at PYE, and then at NIM, the AMF SKYRAD IRT measured about 10K higher sky 
temperatures than the AERI and the MWRP IRT measureed about 20K higher than the AERI.  
Several actions were taken to diagnose the problem including confirming the correct 
configuration of the IRTs and data logger, cleaning the mirror and lens, and replacing the mirror.

After several days of rain beginning 6/2/2006, the three instruments came into agreement. 
It is unknown whether this was a problem with the AERI, MWRP-IRT or SKYRAD-IRT.

• Sky Infra-Red Temperature(sky_ir_temp)
• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)

NIM/MET/M1 - Software problem

Intermittent Failure of Logger to read data from the Barometer.

• Barometric Pressure(atmos_pressure)

NIM/MET/M1  - Optical Rain Gauge Failure

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

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

NIM/GNDRAD/M1 - Reprocessed: Longwave calibration error

Modified pyrgeometer calibration procedures were implemented beginning in December 2003. 
These modified procedures introduced a calibration bias in the longwave data.  The 
previous procedures were re-implemented at all sites between December 2005 and February 2006 to 
restore proper calibrations.									     
The data collected while the incorrect procedures were in place have been reprocessed to 
remove the calibration bias.  The reprocessed 60 second averaged data are based on 3 
instantaneous 20 second data records rather than on 60 1 second instantaneous data records.  
Still, these data are considered far superior to the originally processed data. The 
reprocessed data were archived in February 2007.

• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)

NIM/SKYRAD/M1 - Tracker inoperative

Starting on 9/12 the NIM radiometer tracker drifted enough due to sinking supports and a 
drifting clock that the direct normal measurments (NIP) and the downwelling hemispheric 
diffuse shortwave measurments (8-48) were adversely affected in the afternoon hours.  The 
shortwave hemispheric global instrument (PSP) and downelling hemispheric longwave shaded1 
and shaded2 (PIR) are unaffected by this problem. 

The tracker problem greatly affected direct measurements and affected the diffuse 
measurement to a lesser extent. There are no redundant measurements for these instruments.  
However, during this time range the data collected before local noon (aprox 1140GMT) for all 
shortwave Skyrad instruments appear to be good.

• Instantaneous Direct Normal Shortwave Irradiance, Pyheliometer Thermopile
  Voltage(inst_direct_normal)
• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)

• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)

• null(Raw data stream - documentation not supported)

NIM/MET/M1 - ORG Data Incorrect

The ORG measured around 9cm of rain in a short period while other co-located sensors 
measured no precip.

Use the Present Weather Detector data instead or set the ORG rainfall to 0mm during this 
time period.

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

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