Odd Color-Anomaly on ROVER Camera Calibration Device

ODD COLOR-ANOMALY ON ROVER CAMERA CALIBRATION DEVICE

OK, I was reading the post about Andrew Basiago and managed to download (directly from the NASA site) the much talked about picture "PIA10214". Frankly, I don't see the things he sees in it, but this is another story. The detail in the picture that caught my attention was this:



It is a color calibration target on the Rover Spirit in the form of a sundial.

According to the bloke that has designed this thing it is used “by the camera teams to verify the colors the camera saw.”

This is his design sketch of it on his blog:



Or, alternatively:



Quite odd, isn’t it? I’m no expert in colors and stuff but I wonder how the picture would look like with a bit more green and blue colors in it? Maybe I’m totally off track here, but could anyone explain to me where I’m wrong?

Link NASA

Link Artist Blog



Removed 'All Caps in title



[edit on 10/11/09 by masqua]

reply to post by Fluffytron


The colors of the Martian landscape is a bit of a controversy and I agree that this is odd.
Compare this image from NASA,
Spirit's West Vally Panorama.
with this one here,
Soirit in McMurdo crater.
They look a little different but then how about this one.
Martian Landscape.
I know this is most likely due to different lighting and atmospheric conditions but I have seen many images of the Mars sun dial that didn't look right like the first one you linked. I would guess that this has to do with the limitations of the cameras, Martian lighting and atmospheric conditions.

reply to post by Fluffytron


look up Keith Laney. He has a lot of stuff on this, and hsa several color adjusted photo's. Since he is one of the guys that handles NASA images for NASA, he is likely to be on the right track, IMO.

reply to post by Devino


Spirit's "West Valley Panorama" and the "McMurdo Crater Panorama" that you provided were both false color images, and NASA identified those images properly as such.

You really can't compare NASA's false color images to images labeled as "approximate true color". The false color images are not intended to be true representations of the colors.

Here's what NASA said about the McMurdo image you posted:

This view of the surroundings from Spirit's "Winter Haven" is presented in exaggerated color to enhance color differences among rocks, soils and sand.

Here is NASA's approximate true color image of McMurdo:

This is an approximately true-color, red-green-blue composite panorama generated from images taken through the Pancam's 600-nanometer, 530-nanometer and 480-nanometer filters. This "natural color" view is the rover team's best estimate of what the scene would look like if we were there and able to see it with our own eyes.

Here is a page that has the West Valley Panorama seen various ways -- false color and approximate true color (scroll down to bottom):
marsrover.nasa.gov...
...and the McMurdo Panorama:
marsrovers.jpl.nasa.gov...


...by the way, they are called "approximate true color" because ALL digital cameras are essentially color blind. "Color" digital cameras (yours and NASAs) use computer algorithms to interpret gray-scale images seen through various filters as "approximate color". The light sensors only distinguish gray scales -- computers (either in your personal camera or at NASA's imaging labs) takes an "educated guess" at the true color.



[edit on 11/11/2009 by Soylent Green Is People]

reply to post by Soylent Green Is People


Cool, thanks a lot for your explanation. I knew there was something odd...mistery solved!

reply to post by bigfatfurrytexan


Thanks a lot...now these pictures by Laney finally look right to me...

[edit on 11-11-2009 by Fluffytron]

You might be interested in this website, there is loads of 'true colour' images to look at and compare

areo.info...

I confess I'm too lazy... Thing is, this has been discussed (with nice arguments and exhibits) at great length length, right here on ATS like 2 years ago.

reply to post by Soylent Green Is People


I agree with you but look at the Mars sun dial in the images. In the false color images the sun dial looks like a flat orange color which is indeed false. The thing I find odd is how the different colors of the sun dial do not show. I have always assumed this was due to the limitations of the rovers cameras.

Those colours are the result of using the "wrong" (or more correctly, not the right) filters to the three channels, red, green and blue, that make a RGB computer image.

By using the ultraviolet instead of the blue, for example, it gives colours that are not right (they do not show all the colours) but it's usually enough to have a rough idea of the colours in the scene.

I will look for a good example.

Edit: here you have the same colour target, from Sol 1368, one of those used to made that panorama and the only that has the right channels to make an approximate true colour image.

[atsimg]http://files.abovetopsecret.com/files/59632e3cf2010934.jpg[/atsimg]

Edit 2: The same image but made with L2, L5 and L7 filters instead of the L4, L5 and L6.
[atsimg]http://files.abovetopsecret.com/files/1f4e7fa6c9cc8987.jpg[/atsimg]

[edit on 11/11/2009 by ArMaP]