From Timothy J PARKER
®. . . . . . Subject: Re: Mars -
Tom:
I can't remember who it was
(Damian?) that suggested, a while back, that one could make a gizmo to
introduce an opposite refraction to the atmospheric refraction
mechanically/optically (by tilting the eyepiece slightly), to negate the
atmospheric refraction so that the imaging device has no offsets between
colors. This would be particularly
useful for on-chip color CCDs that use CMY and Green
filters to derive color, because the red and blue both are extrapolated from
the magenta filter (and therefore the refraction can't be completely removed
this way). I've thought to try this out
myself, but we've been socked in with the marine layer since RTMC, so I can't
see Mars unless I drive to a mountain site (what's wrong with this picture?).
planetarily,
(
----- Original Message ------------------------------------------------------
On
> David:
>
> Registering and combining separate images taken in rather narrow
> spectral bands should all but eliminate
the effects of atmospheric
> prismatic dispersion, rather pronounced
given the modest altitude of
> Mars seen from mid-northern latitudes like ours. This may account
for
> the superiority of the resulting R(G)B
images versus those obtained
> with the webcam
used as "single-shot color" device.
>
> Dobby
>
> ----- Original Message -----
> From: David
M Moore
> Sent:
> Subject: Mars -
>
> All
>
> Seeing was potentially
good this morning, but the air is so dry
> with rapid cooling, some breezes developed
just as I was setting up.
> Still I managed to get some useable images.
> I have been imaging the
past several weeks using filters to
> isolate the R and B as I felt it gave a more scientifically
reliable
> image set.
I was still using the TouCam original color
image as
> itself.
I experimented this morning and used a synthesized G to make
> a color image using my original R and B
images. The results look very
> promising! While I may not abandon
entirely imaging in color with the
> TouCam with Mars, it would appear with
this result that imaging in
> separate colors, splitting out the
specific color, and combining as an
> RGB may give superior results in the individual colors as well as
> the final color image. I will continue to experiment.
> I would solicit any
input.
> Thanks
> Dave Moore
Tim PARKER (JPL/CIT, CA, USA)
Jet Propulsion Laboratory, California
Institute of Technology
Mail Stop 183-501
Research Scientist (Geologist)
Mars Exploration Rover
Director, Regional Planetary Image
Facility