I was hoping they would increase the jpg quality of the color mastcam shots like they did with navcams, but the latest batch look even more highly compressed.

Couldn't find an answer so far - can please someone explain why the calibration target on MSL does not have a dustcover or some sort of dust removal technology? What did they calibrate for when all the grey and coloured patches are full of dust? Even here on earth a photographer has to buy a new greycard now and then (at least he should because of colour changing) ...

Thank you!

http://www.nbi.ku.dk/english/research/phd_...011/line_drube/

Thank you for the link. Two more:

The combined CalTarget and iSweep experiment

Magnetic properties experiments [...] Design, calibration, and science goals

Quote form the second link:

Too bad it didn't work now on MSL.

Edit:
Interesting lecture video from Morten Bo Madsen unfortunately in danish

How can I demosaic the bayer filter treated Curiosity raw images ? Is there any appropriate software known ?

Regards, Udo

You can download GIMP (GIMP.org) and the plugin G'MIC(G'MIC) ..

then after opening the file in GIMP; Filters > G'MIC(new window) > Degradations > Bayer reconstruction

Thanks-a-lot. Works !

Regards

Udo

How would the night sky look at Gale Crater? Would the Milky Way be a magnificent sight, or might there be too much dust aloft to have a good view?

I was wondering if the mastcam az/el motors are up to the task of tracking a long exposure shot of the night sky.

I'll go with 'magnificent'. Dust isn't a problem if there's nothing lighting it up. Maybe the stars are only half as bright as from out in space (not a big difference really) but the background is still black. I wish the view from my back yard was that good.

I was wondering whether - in another year or so - a long-exposure shot of Jupiter with the M100 would look good. Of course, we can get superb shots of Jupiter from other hardware, so it would be a bit of a vanity exercise, but interesting nonetheless. And it might give some indirect information about the state of the Martian night atmosphere or some other subtle data.

There was lots of night imaging from Spirit of course. They didn't image the Milky Way, but did image the LMC. One potential problem with MSL is bandpass. The good results from Spirit used the L1 (open) pancam. I believe that has considerably wider bandpass than L0/R0 on mastcam, which has an IR cutoff (cutting above around 700 nm). I'm not sure how important the IR is to imaging the night sky, but that could mean you'd need substantially longer exposures with mastcam. But the efficiency of the detector and speed of the optical system also matters of course. And look at the Spirit images - CCD noise becomes important on long exposures.

As far as tracking, I think that's out. Even if they could manage to move the mast at the extremely slow rate you'd need while taking an exposure, it's an altazimuth mount so frame rotation quickly becomes a problem. Probably better to take multiple short exposures and stack them (with rotation to compensate for field rotation if needed).

Tau is important. The absorption when tau is high means you need longer exposures, which is always harder. I think dust would affect the visibility of diffuse objects like the Milky Way more than stars. Maybe if heating needs aren't too bad, they could do night imaging in the low-tau winter, which they could never do with MER.

Well... Those experiments are too much "combined" on the MSL for my own color calibration tests... The 4 color calibration targets are now "polluted" by the magnet experiments...
See sections from MastCam Sol 13 vs. Sol 44 image. It's a real pity...


And even more than a pity. This was a foreseen event as per page 58 of the "Martian Airborne Dust - Magnetic Properties on Phoenix and Dust on the MSL Calibration Target " thesis by Line Drube in 2011 :
http://www.nbi.ku.dk/english/research/phd_...e_juni2011.pdf/
"It is apparent from Figure 50 that keeping the magnets in the MSL calibration target will quickly ruin much of the blue, green, yellow and red colored calibration areas for their intended purpose. Since less than a year to launch is too late for removing the magnets from the calibration target..."

Curiosity is currently at 4.5 degrees south latitude. If you could cant the rover by that amount in the north-south direction, then the masthead should be able to track objects on the sky's equator by simply adjusting altitude only without any field rotation. Hopefully, the minimum altitude increment of the masthead would shift the image by less than a pixel.

Mark

P.S. I wonder if MAHLI could be used? The arm has so many degrees of freedom that something should be possible for proper tracking. Looking at the arm I think you would still need to cant the rover, but at least you could track objects at different declinations on the sky by adjusting the last axis on the arm. Tracking would be done with the second to last axis. Question again would be if the pointing accuracy is good enough?

The problem is precision. I'd be surprized if MC or MH could slew slowly enough to track the sky, which is about 4 seconds per arcminute. Both MC34 and MH have resolutions of around 1 arcmin/px. So you'd either need to bump something like 1 arcmin every 4 seconds, which is an incredibly fine step, or slew at an extremely slow continuous rate. Either is way outside what they were built to do. And I don't know if you could both move and shoot at the same time to begin with.

But the good news is optical speed. MER pancam is f/20, and still we could image the LMC! MH is f/8.5 and MC34 f/8. So in terms of optics alone, you'd need roughly a sixth of the exposure compared with pancam. (Even MC100 is f/10.) So stacking a series of short exposures might give very impressive results. (But there's still the lower optical bandwidth for mastcam compared with pancam.)

For the case of MC, found a reference: The Mars Science Laboratory Engineering Cameras



So that would be about 15 MC pixels--not so great for tracking the sky then.