SGP/SIRS/E9 - Incorrect timestamp

The data collection computer lost communication with GPS for the affected time period at 
this site. The instrument time is not correct causing the data to be up to 30 minutes 
behind actual time by the end of the affected time period.  The time shift is not linear and 
no known time correction could be applied to the affected data streams.
More information is available contained in PIF P090429.1

• base_time
• alt
• inst_diffuse
• lat
• inst_up_long_dome_resist
• lon
• inst_up_long_case_resist
• inst_up_long_hemisp_tp
• inst_direct_normal
• Irradiance, longwave, downwelling, hemispheric, thermopile (Shaded Pyrgeometer1)(inst_down_long_hemisp_shaded_tp)
• inst_up_short_hemisp
• inst_global
• time_offset
• inst_down_long_shaded_dome_resist
• inst_down_long_shaded_case_resist

• Downwelling Longwave Hemispheric Irradiance, Shaded Ventilated Pyrgeometer(down_long_hemisp_shaded)
• inst_down_long_shaded_case_temp
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• inst_down_long_shaded_dome_temp
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• time_offset
• inst_up_long_dome_temp
• vBatt
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• short_direct_normal_std
• Downwelling Longwave Hemispheric Irrad., Shaded Ventilated Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• base_time
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Downwelling Longwave Hemispheric Irrad., Shaded Ventilated Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• alt
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• down_long_hemisp_shaded_std
• inst_up_long_case_temp
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• up_long_hemisp_std
• lon
• down_short_hemisp_std
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• lat
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std

SGP/SIRS/C1 - SW direct normal data drop out

NIP cable had failed during this time period.

Short_direct_normal data are not recoverable during this time period. However, it can be 
reconstructed using the following formula for each one minute data:
   short_direct_normal = (down_short_hemisp-down_short_diffuse_hemisp)/cos(zenith angle)

• inst_direct_normal

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• short_direct_normal_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)

SGP/SIRS/E9 - Tracker failure

The solar tracker was not functioning during these periods. During both failure events PM 
found the solar tracker in its parked position. PM reset the tracker and it resumed 
normal operations.

Data from instruments directly reliant on tracker operations (short_direct_normal, 
down_short_diffuse_hemisp) are not recoverable. The longwave data should not be affected.

• inst_direct_normal
• inst_diffuse

• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• short_direct_normal_std
• down_short_diffuse_hemisp_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)

SGP/SIRS/C1 - Reprocessed: Upwelling shortwave

The upwelling shortwave hemispheric data were bad 20090914-20091009 due to a broken 
instrument cable.  The cable was replaced on 10/09 at 1711 GMT but the leads were reversed. The 
leads were corrected 10/19 at 2001 GMT.

The data for 20090914-20091019 have been reprocessed. The bad data from 20090914-20091009 
were set to missing in the newly available reprocessed data set. The 20091009-20091019 
data were corrected by applying a (-1) multiplier.

• inst_up_short_hemisp

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)

SGP/SIRS/E9 - Downwelling SW sensor alignment/level

On clear days, the down_short_hemisp data (PSP instrument) exhibit asymmetry in its daily 
output curve especially when compared to derived downwelling shortwave.  Ops corrected 
the problem by re-leveling the PSP on 3/16/2010. The issue may likely be due to a slowly 
sinking platform at this site or inadvertent loosening of instrument hold down screws.  

Problem may have developed slowly over the last year.  Corrections are not easily 
quantifiable.  Suggest using derived downwelling shortwave which is not dependent on the PSP 
instrument:

derived DS = down_short_diffuse + short_direct_normal * cos(zenith angle)

• inst_global

• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• down_short_hemisp_std

SGP/SIRS/E11 - Multiplexer problem

Values of down_short_hemisp, down_long_shaded_hemisp and up_long_hemisp began 
intermittently dropping out beginning 04/29.  This problem gradually became worse, but remained 
intermittent from day to day. 

Site ops reseated the mux connections and replaced the logger wiring panel on 6/1 approx 
1600GMT which corrected the problem.

The automatic quality control flags for the three affected datastreams can be very 
effective at determining the suspect/bad data values for exclusion. Alternatively the affected 
dates and times are given below:
4/29 0302,0345,1312,1405,1905GMT
5/05 0144,1525-1550,1900-2100GMT
5/06 1615,1924GMT
5/10 2000-2359GMT
5/11 1720-1755GMT
5/13 1430-1630GMT
5/14 1700-1900GMT
6/01 1500-1650GMT

• inst_up_long_case_resist
• inst_global
• inst_down_long_shaded_case_resist
• inst_up_long_dome_resist
• inst_down_long_shaded_dome_resist
• inst_up_short_hemisp
• inst_up_long_hemisp_tp
• Irradiance, longwave, downwelling, hemispheric, thermopile (Shaded Pyrgeometer1)(inst_down_long_hemisp_shaded_tp)

• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• up_long_hemisp_std
• Downwelling Longwave Hemispheric Irrad., Shaded Ventilated Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• inst_down_long_shaded_case_temp
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• inst_up_long_dome_temp
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• down_long_hemisp_shaded_std
• inst_up_long_case_temp
• Downwelling Longwave Hemispheric Irradiance, Shaded Ventilated Pyrgeometer(down_long_hemisp_shaded)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Longwave Hemispheric Irrad., Shaded Ventilated Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• inst_down_long_shaded_dome_temp
• down_short_hemisp_std

SGP/SIRS/E11 - Intake Fan Failure

Data were missing from this station from 5/27 to 6/1.  After collections resumed on 6/1, 
the first night (6/2) data revealed down_short_hemisp (PSP) and down_short_diffuse_hemisp 
(8-48) data consistent with ventilator fan failure or obstructed fan filter resulting in 
large thermal offsets.  

On 6/14 Ops cleaned obstructed ventilator fans on both 8-48 and PSP instruments which 
corrected the large thermal offsets.  The PSP was seriously affected and possibly the 8-48 to 
a lesser degree.  

Due to correction on a partly cloudy day the degree of thermal offset cannot be well 
quantified.  Users are advised to avoid the PSP data (down_short_hemisp) completely during 
this time period.  The 8-48 data (down_short_diffuse_hemisp) are suspect.

• inst_diffuse
• inst_global

• down_short_diffuse_hemisp_std
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• down_short_hemisp_std
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)

SGP/SIRS/E9 - TimeCheck Error

The sgp.E9 instruments (EBBR, MET, SIRS, SWATS) time clocks were drifting outside the 
allowable +/-3 seconds.  During the specified period, the swings ranged from -326 to +637 
seconds.  This period was around sunset May 6th (local time) and in the few hours 
immediately after sunset.

• base_time
• alt
• inst_diffuse
• lat
• inst_up_long_dome_resist
• lon
• inst_up_long_case_resist
• inst_up_long_hemisp_tp
• inst_direct_normal
• Irradiance, longwave, downwelling, hemispheric, thermopile (Shaded Pyrgeometer1)(inst_down_long_hemisp_shaded_tp)
• inst_up_short_hemisp
• inst_global
• time_offset
• inst_down_long_shaded_dome_resist
• inst_down_long_shaded_case_resist

• Downwelling Longwave Hemispheric Irradiance, Shaded Ventilated Pyrgeometer(down_long_hemisp_shaded)
• inst_down_long_shaded_case_temp
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• inst_down_long_shaded_dome_temp
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• time_offset
• inst_up_long_dome_temp
• vBatt
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• short_direct_normal_std
• Downwelling Longwave Hemispheric Irrad., Shaded Ventilated Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• base_time
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Downwelling Longwave Hemispheric Irrad., Shaded Ventilated Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• alt
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• down_long_hemisp_shaded_std
• inst_up_long_case_temp
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• up_long_hemisp_std
• lon
• down_short_hemisp_std
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• lat
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std

SGP/SIRS/C1 - Failed Upwelling SW cable

The upwelling shortwave hemispheric (up_short_hemisp) data were missing or incorrect due 
to a bad cable.  Cable was replaced on 6/30 and the problem was resolved.

• inst_up_short_hemisp

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)

SGP/SIRS/E11 - Reprocess: Incorrect calibration coefficients

Likely near 00:00GMT on 11/18/2010 (Site is missing data from 0000 to 0006 on 11/18) the 
calibration coefficients and serial numbers for the SIRS program at E11 reverted to the 
previous year's(2009/2010) installed shortwave instruments. Site ops re-loaded the correct 
program on 11/24.  Reprocessing will be required for all shortwave instruments.
Incorrect cal coeffs applied during this period:
Diffuse PSP: 113.21 W/(m^2*mV)
PSP-US:      115.00 W/(m^2*mV)
NIP:         115.83 W/(m^2*mV)
PSP-DS:      115.95 W/(m^2*mV)
Correct cal coeffs to apply:
Diffuse PSP: 111.05 W/(m^2*mV)
PSP-US:      115.10 W/(m^2*mV)
NIP:         127.22 W/(m^2*mV)
PSP-DS:      121.20 W/(m^2*mV)

Back out old cal apply new:
Diffuse PSP(down_short_diffuse_hemisp): 111.05/113.21=0.98092
PSP-US(up_short_hemisp):115.10/115.00=1.0010
NIP(short_direct_normal):127.22/115.83=1.09833
PSP-DS(down_short_hemisp): 121.20/115.95=1.0453

• inst_direct_normal
• inst_up_short_hemisp
• inst_global
• inst_diffuse

• up_short_hemisp_std
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• short_direct_normal_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• down_short_diffuse_hemisp_std
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• down_short_hemisp_std
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)