Author Topic: SpaceX Falcon 9 v1.1 - ASIASAT-8 - August 5, 2014 - DISCUSSION THREAD  (Read 174437 times)

Offline deltaV

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However, what we see are very short WFDs for maybe one or two seconds with no corruption of the data before the WFD.

If they use global error correction codes one would expect it to go directly from pristine to garbage without ever being degraded. There's no need for a conspiracy theory.

Offline Steven Pietrobon

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However, what we see are very short WFDs for maybe one or two seconds with no corruption of the data before the WFD.

If they use global error correction codes one would expect it to go directly from pristine to garbage without ever being degraded. There's no need for a conspiracy theory.

Error control coding is my speciality. What you say is true for very powerful codes operating near capacity. We don't know what error control coding scheme SpaceX is using. However, the Asiasat 8 flight showed what happens when the signal degraded. The screen didn't suddenly go black, you could see the data gradually becoming more and more corrupted. This is what I typically see on my digital TV when the signal gets bad, as the coding scheme used is not a particularly powerful one. One might argue that the WFD box had failed and was not working. While in that non-working state, we coincidently see the tank views. A possible reason for the WFD failure was the data becoming corrupted, ironically a possible situation that the WFD filter was not tested for.
« Last Edit: 08/15/2014 09:07 AM by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

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