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T O P I C R E V I E Wedmk5000Does anyone know what causes the black line with "moving" white bars in much of the onboard video from the shuttles? The other day, CAPCOM refered to this line as a "leg."Is there some kind of data or telemetry included in the video signal that would cause the line.I think I read something on the net about 10 years ago that said it had to do with the timing of the video siganl against the timing of something else onboard. However, I could not find that reference again.Thanks for any info.Ededmk5000Found an answer as to why there is sometimes a white line in live on-board video from the shuttle:It is because the RCU (Remote Control Unit) and VSU (Video Switching Unit) insert remote control and timecode data to be able to control the cameras from different areas in the orbiter and from mission control. However, the VTR and newer cameras/camcorders are not synced with the VSU and RCU. Therefore, the data for remote-controlling and inserting timecode shows up in the video field (as a horizontal line) instead of during the video blanking period. The line is not always present because the remote control/timecode can be switched off.An extremely detailed file descrbing how the shuttles' video systems work is at: http://www.shuttlepresskit.com/scom/23.pdf
Is there some kind of data or telemetry included in the video signal that would cause the line.
I think I read something on the net about 10 years ago that said it had to do with the timing of the video siganl against the timing of something else onboard. However, I could not find that reference again.
Thanks for any info.
Ed
It is because the RCU (Remote Control Unit) and VSU (Video Switching Unit) insert remote control and timecode data to be able to control the cameras from different areas in the orbiter and from mission control. However, the VTR and newer cameras/camcorders are not synced with the VSU and RCU. Therefore, the data for remote-controlling and inserting timecode shows up in the video field (as a horizontal line) instead of during the video blanking period. The line is not always present because the remote control/timecode can be switched off.
An extremely detailed file descrbing how the shuttles' video systems work is at: http://www.shuttlepresskit.com/scom/23.pdf
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