DQRID : D060921.9
Start DateStart TimeEnd DateEnd Time Data Quality Metric
03/20/2006182009/29/20060945Does not affect quality
NIM/TSI/M1 - Shadowband Misalignment
DataStreams:nimtsiskyimageM1.a1, nimtsimovieM1.a1, nimtsicldmaskM1.a1
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).
  • JPEG data stream - documentation not yet available
  • png
  • MPEG data stream - documentation not yet available

Close this window