[X] My Assistant

[Brian Burns]

Sorry if this has been discussed anywhere but I can't seem to find much information about it - why is it that Voyager's pointing is so haphazard, as in this video of all the RAW Jupiter images - https://www.youtube.com/watch?v=bf5QJ8iFxUs?

I came across this link which says that pointing information for the images exists - http://pds-rings.seti.org/voyager/ck.html, but have also read on this forum that it's not very accurate. Would the information be useful in automatically aligning composite images and mosaics, or is it too coarse? Would it at least be useful in getting general alignments that could be refined by hand?

And does anyone know why the cameras could not be pointed more accurately, or why accurate information could not be returned with the images? I assume it was some technical limitation, but just curious what it might be.

[mcaplinger]

And does anyone know why the cameras could not be pointed more accurately, or why accurate information could not be returned with the images?

Voyager used an articulated scan platform with fairly coarse position feedback. It also used coarse sun and star sensors (the star sensors locked on to one bright star, no scanning of any kind) for attitude information, and for Voyager 1, one of the star sensors failed just after the Jupiter encounter -- https://oce.jpl.nasa.gov/mib/VOY-1.pdf

Remember that Voyager was designed in the early 70s before solid-state imaging even existed. Modern spacecraft use much better star cameras for attitude information, and usually don't have scan platforms (for better or worse) and even then the pointing is typically not accurate enough to perfectly line up colors.

That said, I have no idea how accurate any particular Voyager C kernel might be. Those derived from fitting of the limb in the image (so-called "C smithing") could be very accurate.