Re: Mars 3-D

[P3D Sandman <sandler@xxxxxxxxxxxxxx>]

P3D John W Roberts says:
>The interocular on both the lander and the rover are not too far off from
>the human interocular, and the resolution isn't all that bad - perhaps she
>meant that 15 feet is the cutoff for calculating distances within some
>specified limit of precision?

There is a theoretical limit to how precise they can get.  The size
of a single digitized pixel might be enough to stop good distance
calculations beyond 15.  A rough calculation, at 15 feet (~5 meters)
with a stereo separation of 65mm is .74 degrees.  Depending
of the angle of view and resolution of the camera....that just might
not be very many pixels  (lets say 60 degree view with 1024 pixels
17 pixels/degree or 12 pixels different..Now +/- 1 pixel could end
up with almost half a meter (~1.5 feet) difference...pretty big...that
is for something at 5 meters...what if it is at 20?

Very quick breakdown.

If the lander's camera is not calibrated to do a better interocular
sep......it may be good for human viewing but it would be _very_ hard
to get good numbers.

Sandler


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