NIM/TSI/M1 - Shadowband Misalignment

From installation, the shadowband was positioned south at solar noon until the vernal 
equinox when it began to migrate counter-clockwise until reaching east 37 days later on 4/26 
(about 9 days before mid-spring). The shadowband at solar noon continued to migrate until 
reaching its most northerly position (~15 deg) on the summer solstice (if everything was 
perfectly aligned, it probably would have been pointed north on this day). It then began 
to migrate clockwise and reached east again 56 days later on 8/16 (about 14 days after 
mid-summer). As expected, the shadowband reached its most southerly position on the 
autumnal equinox but was about 10 deg off of being due south. 

With the apparent alignment problem, I don't understand why the shadowband was mostly 
blocking the sun. When I started noticing this offset in May, I chose to leave it alone 
because I felt that adjusting the shadowband to where I thought it should be would cause it to 
not block the sun at either sunrise or sunset. 

The alignment was corrected on 9/29 (6 days after the day of the autumnal equinox).

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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)

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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)

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