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First Pictures From Mars Phoenix Lander
Now that the solar panels have been deployed, the Mars Phoenix Lander has begun sending back pictures of the red planet to the hungry space geeks of earth. In just a few weeks the claw will deploy and they'll start digging a hole. The scientists expect to use the dirt to construct a little sand castle which they will defend with several GI Joe action figures, and a bald barbie stolen from their sisters. Oh, and maybe find water or bacteria.
It's more scientifically useful to put a really good black & white camera onboard, and then include some filters, than to put a color camera.
IIRC, pretty much all the color images from previous landers are composites of multiple images with different filters, making a human-eye approximation.
Have you been touched by his noodly appendage?
Here. The blue ellipse was the intended landing zone, the red the actual, and the green box was... umm... a Martian football field? I dunno.
Have you been touched by his noodly appendage?
I think it's called regolith.
When an object is too bright for a CCD camera, it causes excess charge to "bloom" into adjacent pixels. It's a common artifact.
Do you know how your spare Canon camera works...? You guessed it, by having a monochrome sensor with appropriate filters in front of certain elements. The cameras on the lander will no doubt out-perform your canon in terms of sensor quality, lens quality, focal range, etc. The only advantage the Canon might have is in the number of megapixels.
When our name is on the back of your car, we're behind you all the way!
As far as space missions and human-friendly color images, the bottom line is that transmission of images is expensive. Thus, they don't use the human-friendly wavelengths very often. However, there are various mathematical ways to approximate such using the other filters plus some sample calibrations, and this is usually what we see in press-release images from most missions.
For example, the rover missions usually use infrared filters instead of "red" filters for that end of their range; but they can use that one to approximate the red filter with some adjustments.
I suspect they will do similar things with this mission once it gets up to speed. The preliminary color images are 2-filter approximations. If they do what the rovers did, they'll use 3 filters that don't match human eyesight but compensate with digital processing to give us "human" approximations. They'll be better than these early 2-filter approximations.
If you as a human are upset at this approximation; fish, birds and reptiles will be even more angry because they have 4 color cones instead of 3. (We'd probably have four if our mammalian ancestors were not nocturnal. Damned those mammal-squishing dinosaurs who made us hide in the darkness! I wish meteors on you for limiting our color!)
Table-ized A.I.
CCDs are only one kind of imaging technology. It's not necessarily the best, there are trade-offs. The other major type is CMOS, which has several sub-types and variations.
The rovers Pathfinder, Spirit and Opportunity use a lot of different color filters that are placed in front of the imaging sensor. Because the filters are fixed, 3 CCD, or 3 CMOS cameras isn't very good for science, it's good for making a pretty picture.