Model Forum / General / Rockets / January 2004

if you look closely you can see my tinfoil hat at the edge of the picture.

This seems like an "impossible" shot.  Anyone know how it was taken?

http://marsrovers.nasa.gov/gallery/press/opportunity/20040125a/p150xL_per_
str-B0R2_br2.jpg
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I do not know the specifics from any definitive source, but it would be
something like this:

Don't think of it as one single photo pointing straight down. Think of it as a
camera on wide angle that is pointing outwards and down, down enough to include
straight down in its field of view. Then take a shot, rotate a bit to the
right, take a shot, rotate to the right, etc, till it's completed a full 360
degrees. Then "photo stitch" with software into one image.

You can see a few "artifacts" of the stitched photo at the very top, glaringly
so. And to the lower right, on the ground, two dark areas that have 90 degree
corners. Also on the lander itself, one of the ramp "petals" shows a great deal
of stitching irregularity, both on the outer edge and the crosshatch pattern
that is not lined up.

Now, for anyone who might have caught the first images live from Opportunity
late Saturday night, I think it was this very photo that built itself up over
time. Actually now that I think of it, it seemed like it came in with some
inner segments first, then outer segments later, as though the camera was
angled with at least two if not three different elevation angles. So rather
than thinking of this one photo-stitched in azimuth-only segments like a clock
face, it was more like dartboard segments.

It is interesting though that the arm of the camera managed to be left out of
the completed stitched image. Unless it's part of those artifacts at the top.

BTW - when ground tests were made with the Viking Lander camera prototype in
the early 1970's, the engineers made a "fun" photo where the slowly rotating
camera was shooting a horizontally-aimed panoramic 360 degree photo (the Viking
camera, IIRC, shot pretty much a vertical "slit" digital image then rotated
slightly to the next "slit" position, on and on so the adjacent slits made up
the horizontal portion of the field of view). As the camera slowly rotated past
them so they were no longer in the field of view, the engineers ran around it
in the other direction then posed again, and again, so the final completed
photo looked like there were clones of the engineers all posing together.  

- George Gassaway