If you look at the bench photos of the Navcams in Figure 3 of http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2738.pdf you can see a small black round object adjacent to the lens. A better picture is at http://mars.jpl.nasa.gov/msl/news/images/MSL_cams.jpg I believe that's the vent Justin mentioned. No, dust can't leak through, and I'd have thought that a light leak would be unlikely but perhaps not impossible.

I don't know how the SPICE location is updated with information from outside the rover system. The rover basically can't know its absolute location in the Mars frame all by itself to good accuracy over a long time scale. The team uses map products that have the current site as the origin, so we never really use the SPICE location for anything in absolute terms as far as I know.

Then there's the question of how well the orbital mosaic was georectified in the first place. All in all, I suspect that putting the location on a map in an automated fashion using just the SPICE would be difficult, if not impossible (but I haven't really tried it, so I can't be sure.)

Are you familiar with the coastline paradox? http://en.wikipedia.org/wiki/Coastline_paradox

There are so many error sources for odometry that it may not be physically meaningful to even discuss the "true" value. Even figuring out where the rover is at any given moment isn't free of ambiguity.

I think you're doing a great job with the data you have.

Are the JPL JPEGs for the MSSS cameras stretched? I really don't know. One could tell by comparing them to raw PDS images.

Most of our images are autoexposed and really shouldn't need to be stretched.

Our Mastcam color correction basically multiplies red by 1.2 and blue by 1.25 or so. Of course you have to apply that in linear space and then gamma-correct the image.

For reference, here's what 0439ML0017890030201646E01_DRCX.IMG looks like converted to a JPEG.

Before I saw John's message, I was going to say that this looks consistent with what the PDS DRCX and DRCL products look like. See figure 5.1-2 in the PDS SIS. But now it seems like this mosaic wasn't derived from the RDRs but the EDRs, which means that any relationship between this color and the "actual" color is purely coincidental.

From the SIS:

http://solarsystem.nasa.gov/europa/sdt2013.cfm has a bunch of reports and other information from the Europa SDT, and is useful background reading if you're interested in Europa mission architectures.

Not to me. Shielding is easier to make than big optics and may well weigh less.

If people want to get some insight into some of the engineering that goes into these sorts of missions, the JUICE proposal information is a good read http://sci.esa.int/juice/ JUICE is actually a fairly good start for a Europa mission, too bad they didn't pick our camera

Less of a problem, though getting non-volatile memory to survive is still a significant issue.

At any rate, we were discussing this in the context of a very small spacecraft. IMHO, this is simply infeasible with current technology for a whole host of reasons.

As for sensors, there's nothing I can say without getting into competition-sensitive areas. From an engineering perspective, I don't see a lot of rational and realistic system trades having been made as far as Europa missions are concerned.

The lack of specs makes this hard to evaluate, but the box looks like it weighs multiple kilos and it doesn't say what memory technology it uses.

A typical box designed for the GEO environment will have a hard time at Jupiter without a lot of extra shielding. A lot.

Using what as a storage medium? Flash is quite radiation-soft and MRAM, while promising, is not dense enough yet.

A lot of the mass in a telecom system is in the modulation and RF circuits. The "Small Deep Space Transponder" http://en.wikipedia.org/wiki/Small_Deep_Space_Transponder weighs 3 kg and doesn't include the output power amplifier.

Define a detailed mass breakdown with components you can actually buy and I'll believe it. Until then you're just writing science fiction.

I'm not an etymologist but "glory" is a well-accepted term that appears in popular scientific literature all the time (see, e.g., the references at the bottom of the wikipedia article), at least in the United States.

Perhaps there is some technical distinction between different effects, or perhaps it's called something different in other countries.

https://twitter.com/uhf_satcom is the most reliable source at the moment IMHO, and nothing has been seen.

I'll let you work out the probabilities that of four pairs of two cameras the noisier ones might end up on the left N of 4 times, but they aren't zero for any values of N, are they?

And AFAIK the value of N that really happened was 3, at most.

Many parameters are unique to each image sensor. Expecting all cameras to be identical is unrealistic -- there's no such thing as an "exact duplicate".

Perhaps, but that's what the MSSS cameras send from Mars most of the time, so you're stuck with it.

For most applications it's really fine.

You might investigate whether this was the case before the swap from the A side Navcams to the B side.

This discussion should probably be moved over to the images and cameras subforum.

I guess I'm a little surprised that http://en.wikipedia.org/wiki/Hackers_%28film%29 is still in the zeitgeist.

That's a bit of a false dichotomy IMHO.

At any rate, I wasn't talking about "art", I was talking about pushing the auto white balance button and making an invalid claim about what that meant. You all are certainly free to make whatever enhancement to the images you want. Ansel Adams dodged the heck out of his images, but he didn't then claim they were radiometrically accurate (or even, AFAIK, that that's "what it really looked like"). I'd be the first to admit that the raw version of Moonrise, Hernandez, New Mexico is pretty blah. http://www.kevinshick.com/blog/2013/4/revi...ng-hernandez-nm

Gee, thanks. I'll try to remember that one the next time I spend a month doing camera calibration.

Are you trying to get me into trouble, Doug?

I knew that of course, and I said what I said. I think the products in auto-white-balance form look good to some people (I'm not one of them but de gustibus non est disputandum) but the "Earth-like" claim is simply not correct; at best it's an oversimplification.

I wrote the following for the "white-balanced" PDS data product documentation describing the processing I recommended (not auto white balance):

Unless you are using a much more sophisticated technique than the results would suggest, this is not what you are doing at all. That was exactly what my Monument Valley (on Earth) exercise was trying to show. The images are red because the target is red, not because the lighting is somehow reddish.

The press release claims about Earth-like lighting are simply inaccurate.

In response to people who feel compelled to "white-balance" all the mosaics they post (I won't name names, you know who you are) here is a subframe of an image of Monument Valley from wikipedia http://en.wikipedia.org/wiki/File:Monumentvalley.jpg. The original is on the left and an auto white-balanced version is on the right. Do we have to discuss which one is closer to "natural color"?