The descent stage did crash at the same azimuth as the sun within a few degrees, but the sun elevation was about 30 degrees at the time, as you can see in the rear hazcam images. So it seems unlikely to me that this dimming was caused by the impact plume. I have no idea how much of a flash the crash might have caused, but given that the impact site is over the horizon I'd also find it hard to believe that any noticeable extra illumination was caused. The simplest explanation seems like non-uniformities in the dust around the rover.

The exposure time was constant though this whole sequence and none of our cameras have aperture or gain adjustments. The images are square-root companded.

That said, there's only so much one can do with the thumbnails. So a careful analysis of the full frames, and understanding just what the shadow geometry that is causing this narrow strip of sun, might be interesting.

I did some statistics on the thumbnails and there are definitely 4-5 brightening-dimming cycles post-landing (frames 650-900 or so.)

Nice video, the best I've seen yet of the post-landing data. I think the flashing is just variation in the dust cloud opacity (and possibly shadowing by the descent stage, not sure of the timing on that); it never seems to get any brighter in the sunlit strip than it is at the end. I've looked at all of the thumbnails and there is some flashing, perhaps not as much as your video shows.

As far as I know they aren't decompanded or stretched. Of course you can't tell if they were commanded with sqroot or some flavor of linear (it's an option) so I caution everyone against trying to do photometry.

You could look at ftp://pdsimage2.wr.usgs.gov/cdroms/Mars_R...nt/marcisis.txt to see the companding table used for MRO/MARCI. Why would they be different?

I often tell people who are fond of such numeric metrics as SNR, MTF, ENOB, etc, that no matter how optimal those numbers make your camera sound, anybody can tell a good image from a bad image. I think the MMM images hold up pretty well.

That said, you could work out the best possible SNR we could get from the Truesense datasheet. You can't ever do better than sqrt(fullwell) for a single measurement due to shot noise and these sensors have a fullwell of 20K-40K electrons so 140:1 to 200:1 is as good as it could be.

shot noise = sqrt(signal), so shot noise is higher at higher signal levels. The square root encoding is coarser at higher levels, finer at lower levels.

You could have a philosophical debate about what this means, but that's the way our cameras work.

I am not authorized to put any data out, in any form. You might want to take a look at http://blogs.agu.org/martianchronicles/201...8/blogging-msl/ -- Ryan discusses in general terms the rules that we operate under. I am constantly evaluating each of my posts to make sure that it is only derived from public information.

If you don't like it, complain to my boss.

The MAHLI paper I've referred to several times before is an excellent source of this kind of information. From section 7.5.1:

"Acquired as 12-bit images, MAHLI data are converted onboard the instrument, without loss
of information, to 8-bit images using a square-root companding look-up table."

I have no idea what your point is. It would take me about a minute to process all these images and post them. It's the permission to do so that's lacking.

What would be more in keeping with the spirit of the data release policy (IMHO) would be for us to demosaic the data and then JPEG that, but I can't do either one without permission. If raw data acquisition becomes common I'll ask, but I don't think it's worth it for a relative handful of images.

The Marsdial is roughly 7.6 cm square and one side is 296 pixels long in the 34mm image. The IFOV of the 34mm is about 218 microrads, so the distance is roughly 1.2 meters.

Yes, but I'm not sure they're distinguishable in any meaningful way from high-quality JPEGs; the old raw versus compressed debate familiar to all digital photographers. I'd rather have five JPEGs than one raw myself.

Based on looking at the public website thumbnails, the next batch of images will have been compressed with varying JPEG quality. Then I think they'll be decompressed and recompressed at a constant quality for public release, so I'm not sure what they'll look like. Be warned.

I've lost track of what's concerning you guys.

Straight bayer images were sent down as part of a calibration activity. We demosaic them and look at them, they're fine. Then JPL JPEG-compresses the original raw files for public release and and introduces these artifacts, which is clearly the wrong thing to do. Fortunately I think the use of raw files will be rare, so this should be an isolated incident.

Actually, MAHLI can take this sort of mosaic with the appropriate arm movements.

20 JULY 1969 by W.W. Cooper

They made it, we all made it, just a bit
like Vikings leaving runes and little more.
taking the lesser light where God placed it
to show ourselves just what a heaven's for.
They loped like diving-suited kangaroos
over that sterile world of one night stands,
driving moon bugs and golf balls to amuse
the children, while the stars slipped through our hands.
They're gone now to their shrinks and shrunken space.
The praise is theirs; it's ours to wonder why
the world's still flat and dreams are out of grace.
So I, believing less each summer, pry
open that lost last year to see the bright
earth jewel smooth and blue in velvet night.

I'm not sure what the dashed line is really supposed to mean. The IR-cutoff response is shown in blue, green, and red, but all the filters have been normalized to their peaks, so you can't, for example, compare the R2/L2 narrowband response to the IR-cutoff blue response, or the IR-cutoff blue to the red. This plot was just intended to give an outline of where the bandpasses are.

The plot in 2541.pdf is not a transmission curve, it's a response curve and thus modulated by the detector QE. The JPL web page looks pretty close.

I am really blown away by both Damien's and James' versions of the pan. Thanks to both of you! Hopefully we'll continue to provide you with more and better raw material. I'm not sure we will ever send back a full 360 100mm pan (roughly 10 times more images than these) but if we do I'm sure you'll be up to the challenge!

PDS requires you to archive, in decompressed raster form, whatever you got from the spacecraft. It was discussed upthread whether all of the raw frames will ever be returned from EDL; if they are, then they'll end up in PDS, and if they're not, they won't. I believe the six-month clock starts running when the last image that will be in a particular archive delivery is received.

Yes, but unpronounceable three-letter acronyms I was used to dealing with already: MGS, MCO, MPL, MRO, LRO. I finally started calling Mars Odyssey that, but only because "Mars Surveyor 2001 orbiter" really was too long.

Wow. Very nice job.

Adding MSSS to the credit line would be appreciated, though I think I'll hang it up as is anyway.

http://www.lpi.usra.edu/meetings/lpsc2012/pdf/2541.pdf at least describes the order of filters L0-L7 and R0-R7.

Absolutely correct, even channels where the Bayer pattern isn't transparent, and which would otherwise be tinted (like the thumbnails) are sent in grayscale.

You might very well think they were shot in the same order as shown in http://www.redorbit.com/images/pic/63392/c...rovers-mastcam/ -- I couldn't possibly comment.