NSA/SKYRAD/C1 - Reprocess: PIR identified as unshaded is really shaded

On 5/15/02 the Global PIR was moved from the unshaded position on the Skyrad stand to a 
shaded spot on the tracker.  It is still using the same Logger channel as it did as an 
unshaded PIR even though it is now shaded.

• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Minima(down_long_hemisp2_min)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2(down_long_hemisp2)
• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer2(inst_down_long_hemisp2_tp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Standard Deviation(down_long_hemisp2_std)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Pyrgeometer2(inst_down_long_hemisp2_case_temp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Maxima(down_long_hemisp2_max)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Pyrgeometer2(inst_down_long_hemisp2_dome_temp)

NSA/SKYRAD/C1 - IRT failed

• Sky Infra-Red Temperature(sky_ir_temp)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra Red Temperature Minima(sky_ir_temp_min)

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra-Red Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - IRT incorrectly configured

The IRT was removed for repair and replaced with a
spare that was not configured properly.  Data are incorrect.

• Sky Infra-Red Temperature(sky_ir_temp)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra Red Temperature Minima(sky_ir_temp_min)

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra-Red Temperature(sky_ir_temp)

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 Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red 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 Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra-Red Temperature(sky_ir_temp)

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 Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra-Red Temperature(sky_ir_temp)

NSA/TSI/C1 - camera lens covered

The shadowband was not properly masking the sun so the camera lens was covered on 4/13 to 
prevent damage to the CCD. On 4/20, the mirror was blown off by a snow storm and the 
instrument was brought inside for repair. The mirror was replaced, the lens uncovered, and 
the instrument reinstalled.

• JPG data stream - documentation not supported(JPEG data stream - documentation not yet available)

• PNG data stream - documentation not supported(png)

• Pixel count: number thin in horizon area(region.horizon.count.thin)
• Relative \'strength\' of direct sun(sun.strength)
• Pixel count: camera and sun strip mask(count.mask)
• Sunshine meter(sunny)
• Pixel count: number opaque in horizon area(region.horizon.count.opaque)
• Pixel count: number total in horizon area(region.horizon.count)
• Pixel count: number total indeterminant(count.unknown)
• Pixel count: number opaque in zenith circle(region.zenith.count.opaque)
• Pixel count: number total opaque(count.opaque)
• Pixel count: number opaque in sun circle(region.sun.count.opaque)
• Pixel count: number total thin(count.thin)
• Pixel count: number total between horizon and processed circle(count.sub.proczen)
• Pixel count: box, outside mirror area(count.box)
• Pixel count: number total in processed circle(count.sky)
• Pixel count: number total in sun circle(region.sun.count)
• Pixel count: number below horizon in image(count.sub.horz)
• Percentage thin cloud(percent.thin)
• Percent opaque cloud(percent.opaque)
• Pixel count: number thin in sun circle(region.sun.count.thin)
• Pixel count: number thin in zenith circle(region.zenith.count.thin)
• Pixel count: number total in zenith circle(region.zenith.count)

NSA/TSI/C1 - shadowband misaligned

At several times during this period the shadowband did not mask the sun because the mirror 
was not properly secured. Attempts were made to align the mirror on 4/2, 4/3, and 4/10.

• JPG data stream - documentation not supported(JPEG data stream - documentation not yet available)

• PNG data stream - documentation not supported(png)

• Pixel count: number thin in horizon area(region.horizon.count.thin)
• Relative \'strength\' of direct sun(sun.strength)
• Pixel count: camera and sun strip mask(count.mask)
• Pixel count: number opaque in horizon area(region.horizon.count.opaque)
• Pixel count: number total in horizon area(region.horizon.count)
• Pixel count: number total indeterminant(count.unknown)
• Pixel count: number opaque in zenith circle(region.zenith.count.opaque)
• Pixel count: number total opaque(count.opaque)
• Pixel count: number opaque in sun circle(region.sun.count.opaque)
• Pixel count: number total thin(count.thin)
• Pixel count: number total between horizon and processed circle(count.sub.proczen)
• Pixel count: box, outside mirror area(count.box)
• Pixel count: number total in processed circle(count.sky)
• Pixel count: number total in sun circle(region.sun.count)
• Pixel count: number below horizon in image(count.sub.horz)
• Percentage thin cloud(percent.thin)
• Percent opaque cloud(percent.opaque)
• Pixel count: number thin in sun circle(region.sun.count.thin)
• Pixel count: number thin in zenith circle(region.zenith.count.thin)
• Pixel count: number total in zenith circle(region.zenith.count)

NSA/TSI/C1 - frost/condensation in lens

The sky image appeared hazy and was corrected by cleaning the neutral-density filter and 
lens of the camera. The determination of cloud fraction may be affected.

• JPG data stream - documentation not supported(JPEG data stream - documentation not yet available)

• Percentage thin cloud(percent.thin)
• Percent opaque cloud(percent.opaque)

NSA/SKYRAD/C1 - Tracker inoperative

Tracker stopped working at this site during the time range specified. Reason for failure 
is unknown.  Tracker power cycled and restarted by maintenance 06/30 2008 1740 GMT.

The short_direct_normal (NIP) and down_short_diffuse_hemisp (8-48) data are bad during 
this time.  Data are not recoverable.

• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)

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