NSA/SKYRAD/C1 - IRT incorrect min/max value

The values of valid_min and valid_max for field sky_ir_temp were incorrectly assigned to 
-49.7 and +50.0 C, respectively. The actual values should be -60 and +40 C.

• sky_ir_temp_min
• sky_ir_temp_max
• IR Brightness Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - IRT measurements during precipitation events

The IRT measurement of sky/cloud temperature was in question during
precipitation events because rain or snow could accumulate in the
upward-pointed lens barrel. This was corrected by reorienting the
IRT to measure the sky temperature as reflected by a gold mirror.

• sky_ir_temp_min
• sky_ir_temp_std
• sky_ir_temp_max
• IR Brightness Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - Noisy PIR data at Barrow

PIR1 data is noisy throughout the entire period, though there is still a definite signal 
through the noise.

• down_long_hemisp_shaded1_max
• down_long_hemisp_shaded1_std
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer1(down_long_hemisp_shaded1)
• down_long_hemisp_shaded1_min

• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer1(down_long_hemisp_shaded1)
• down_long_hemisp_shaded1_max
• down_long_hemisp_shaded1_min
• down_long_hemisp_shaded1_std

NSA/SKYRAD/C1 - Downwelling IRT bias

The downwelling IRT was measuring higher sky/cloud temperatures than the AERI. The problem 
was corrected when the mirror was replaced.

• sky_ir_temp_min
• sky_ir_temp_std
• sky_ir_temp_max
• IR Brightness Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - Tracker Inoperative

A blown fuse resulted in the tracker not shading the PIR and B&W
and the NIP not following the sun.

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• short_direct_normal_std
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• 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)

NSA/SKYRAD/C1 - itermittant IRT bias

A problem with the SKYRAD IRT that itermittantly produced a gradual increase in the sky 
temperature measurement then a sudden correction, as compared to AERI, appears to have been 
caused by a combination of a failing IR detector, a poor signal cable, a contaminated 
(with condensation or frost) mirror or lens, and low ambient temperatures. The positive 
bias was apparently not consistant in either frequency or duration but on days when the 
unusual behavior is observed, it usually occurred from about 00:00 to 06:00 local time. 

The instrument was repaired and recalibrated and the signal cable replaced.

• sky_ir_temp_min
• sky_ir_temp_std
• sky_ir_temp_max
• IR Brightness Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - Summer solstice shading of radiometers

On and around the summer solstice, the NIP (Direct Normal shortwave measurement) and PSP 
(global hemispheic shortwave measurement) radiometers are shaded by other instruments or 
support structures.  Shading azimuths have been determined for this site.  The radiometer 
mentor suggests not using the data from the NIP and PSP radiometers when the sun is 
within the following azimuth bounds (typically from May 8th to August 5th of each year):
Instrmt Obstruction     AzStart     AzEnd     
NIP     rad table       346         358
NIP     met tower       13          15
PSP     mfrsr           6           16

• psps_sd
• psp1_sd
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• psps_mean
• psps_min
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• nip_sd
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• psp1_min
• psp1_max
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• nip_mean
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• nip_min
• psps_max
• nip_max
• psp1_mean
• down_short_hemisp_std
• short_direct_normal_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)

NSA/SKYRAD/C1 - Missing data

Data are missing and unrecoverable.

• vBatt
• inst_down_long_hemisp2_tp
• lat
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• sky_ir_temp_min
• sky_ir_temp_max
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer1(down_long_hemisp1)
• alt
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• logger_temp
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• down_short_hemisp_std
• down_long_hemisp1_min
• inst_down_long_hemisp1_tp
• short_direct_normal_std
• inst_down_long_hemisp2_dome_temp
• time_offset
• IR Brightness Temperature(sky_ir_temp)
• down_long_hemisp1_max
• inst_down_long_hemisp2_case_temp
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• inst_down_long_hemisp1_dome_temp
• time
• lon
• down_long_hemisp2_min
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• down_short_diffuse_hemisp_std
• down_long_hemisp2_max
• down_long_hemisp2_std
• inst_down_long_hemisp1_case_temp
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer2(down_long_hemisp2)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• sky_ir_temp_std
• base_time
• down_long_hemisp1_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)