DQRID : D130116.4
Start DateStart TimeEnd DateEnd Time
09/25/2012215911/08/20121745
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Subject:
MAG/TSI/M1 - Shadowband misalignment
DataStreams:magtsiskyimageM1.a1, magtsiskycoverM1.b1, magtsicldmaskM1.a1
Description:
The mirror was not being controlled correctly so the shadowband did not block the sun 
because the encoder failed. Also, the shadowband was not correctly positioned in the 
processed image while at port because the INS system failed.

On 10/19 while at Long Beach port, the encoder was replaced and software was installed to 
get the mirror control board to receive the SeaNav data and correctly position the 
shadowband to mask the sun in the visible image. However, the position of the shadowband in the 
processed image was not correct because the imaging software needed to be configured to 
independently read the SeaNav information.

On 11/8 while at Honolulu port, the TSI software was upgraded at 17:10 and the position of 
the shadowband in the processed image was corrected. However, because SeaNav failed and 
course-over-ground was being used as a surrogate for heading, the heading is 0 deg when 
the ship speed is < 1 m/s. So the platform heading was changed manually at 17:45 to 
correct the position of the shadowband in the visible image while the ship was in port. 

This method was used by the site technicians to configure the TSI upon arrival and 
departure at port until the ship navigation system was replaced on 12/7 at 9:00. The $TSINV 
heading value became accurate while in port so the position of the TSI shadowband was 
automatically controlled correctly both at sea and at port.
Suggestions: 
Measurements:magtsiskycoverM1.b1:
  • Pixel count: number total in horizon area(region_horizon_count)
  • Pixel count: number opaque in horizon area(region_horizon_count_opaque)
  • Pixel count: number total in zenith circle(region_zenith_count)
  • Pixel count: number thin in horizon area(region_horizon_count_thin)
  • Pixel count: number thin in sun circle(region_sun_count_thin)
  • Pixel count: number total in sun circle(region_sun_count)
  • Percent thin cloud(percent_thin)
  • Pixel count: number opaque in sun circle(region_sun_count_opaque)
  • Percent opaque cloud(percent_opaque)
  • Pixel count: number thin in zenith circle(region_zenith_count_thin)
  • Pixel count: number opaque in zenith circle(region_zenith_count_opaque)
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magtsicldmaskM1.a1:
  • PNG data stream - documentation not supported(png)
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magtsiskyimageM1.a1:
  • null(JPEG data stream - documentation not yet available)
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