A lot more detail about the "Maxwell Plan" here...

http://roadtoendeavour.wordpress.com/2010/...al-to-the-metal

I understand that if wheel damage was not an issue then it would be easy to plan 140m drives for Oppy. This has restricted Oppy's progress to 70m per day.

What has occured to me is that it would be possible to plan two rather than one 70m drives at a time and on the second day to simply to perform the second 70m drive without waiting to analyse end of drive photos. The second day's drive would be completely safe because the previous days photographic coverage from no more than 140m away would be adequate.

My plan would largely eliminate the problem of restricted SOLs.

What I have observed is that often a 70m drive day alternates with a resting day. If my plan was adopted then a cycle of driving for two days driving followed by one day resting would result in increasing the ground covered every six days from 210m to 280m.

No, the limit of 70m is because that is the maximum distance they are comfortable doing a blind drive in this terrain, to do any further auto-nav is needed which up to now has required forward drives. It is these forward drives which are a problem for the wheel currents. This is why Scott is proposing this complex plan of backwards-autonav to go further without the rover drivers getting the images and checking that it's safe. When we are out into the 'parking-lot' terrain then it is possible they could push the blind drives a little further, but I doubt they'll be >100m

Since we are talking about blind drives here one thing worth mentioning is that when the concept of blind driving was first planned for, the best ground resolution they had was the MGS MOC with an optimum resolution of 1.5 x 1.5 m/pixel. So the chance of surprise encounter with problematic ground relief was significant. After landing we were then fortunate to acquire some nice MOC cPROTO derived images which had a resolution of 0.5 x 1.5 m/pixel where you could start to see some smaller ground features as in this shot of Spirit at Bonneville Crater. Now we have the HIRISE images with a resolution of something like 0.25 m/pixel which allows us to see the rover tracks quite clearly and in hindsight we can identify objects like Block Island from orbit.

So one of the things I've been wondering is if they have updated or narrowed the original safe driving parameters or the rules for blind drive segments in light of the ability to have a decent look at the planned drive route from above.

Secondly has there been any though of applying super-resolution image stacking techniques to a series of HIRISE images to further improve on the ground resolution which could assist in safely loosening some of the blind drive parameters. I'm sure this would require some immense logistical planning and targeting to acquire enough images under identical lighting conditions. Has anyone heard if the concept of stacking multiple HIRISE images for improved resolution has even been discussed?

I'm pretty sure this issue has been rosen here (before MRO launch IIRC) and the answer was that the technic used with MGS was not applicable to MRO... but I can't remember why...and I think it was an answer from Doug. I may be wrong but...

Can't do cProto-- I think it involved slewing the camera or spacecraft-- with a pushbroom camera, but you can probably stack.

My idea with hirise was to take late day images with long shadows to emphasize drift topography, but even that's a tall order since it passes overhead at the same time every day.

Apparently my blog has been playing up today, so if anyone has tried to access the post on Scott's plan but been unable to, here's what he wrote me:

"You probably know already that we used to do ~ 70m blind drives,
followed by an autonav segment. (Autonomous hazard avoidance, that
is.) We had to quit that because of the RF wheel currents: HAZCAMs
don't give good enough range data in Meridiani terrain to support
autonav, and the NAVCAMs have to look *forward* for autonav, because
behind us the LGA is in the way -- but we can't drive forward any
more, because it makes the RF wheel currents rise. But I thought of a
possible way around that limitation.

"Roughly, if the experiment works, here's the eventual procedure.
First, we do a long blind drive (just a little shy of 70m), followed
by a slip check. Now we're good to go another 20m, the normal
distance between slip checks.

"We slew the NCAMs around so that they're almost seeing the LGA, but
not quite, an azimuth of 162.5 degrees in rover-frame. Now we turn
*Opportunity* the remaining 17.5 degrees (clockwise) so that the NCAMs
are looking straight along our intended drive path. We image the
terrain for hazard avoidance and turn back 17.5 degrees anticlockwise.

"At this point, we're aimed (that is, our rear end is aimed) at our
destination and we have imagery in the drive direction. We do a
straight-backward step of 1m (actually 2 x 50cm steps, for technical
reasons) toward our goal, telling Opportunity to take the step only if
the hazard-avoidance imagery we took shows it to be safe. Then we
just repeat this turn/image/turn/step loop for 20m worth of driving.

"It's a little more complicated than this, because we first have to
drive about 2.5-3m blind to get onto the nav-map data (the nearest
stuff we can see looking over the rear solar panels is about 2m away)
and for other reasons, but that's the basic gist of the idea. If it
works, we can go 90m/sol rather than 70m/sol, a 29% drive-rate
improvement. There will be sols where this doesn't work -- we're
heavily constraining what Opportunity is allowed to do, and if she
sees something scary, this procedure doesn't let her drive around it;
also, the turns-in-place might elevate the RF currents, in which case
we'll have to abandon it; and there are other things that can go
wrong. But if this worked perfectly every time, it would cut nearly
40 drives out of our trek to Endeavour -- a 2-3-month savings, at
least, probably actually more than that.

"In a real blue-sky future, we can do a slip check at the 90m point,
followed by *another* 20m of hazard-avoidance driving, and so on. We
can have hazav-only drive sols, similar to what we did over
President's Day weekend in 2005. When the terrain is a little
friendlier, we can do longer blind drives before the hazard-avoidance
segment(s). And there are other possible optimizations. Right now, I
want to perform a basic experiment to see if this even works."

A HUGE thanks to Scott for taking the time to write and explain all this to me, and for us.

I wasn't referring to the MOC cPROTO "pitch and roll" orbiter technique which is entirely not applicable to HIRISE. I was referring to super-res stacking.of multiple images taken the same time of day.

Thanks for sharing this, Stu, and of course many, many thanks to Scott for taking the time & effort to inform us so thoroughly & clearly!

The super-stacking question is interesting, Dan. How far can they go? Based on the discussion between Ralph & Jason over on the Titan thread (EDIT: which for some reason I can't find right now), it seems that 'resolution' is a fairly complex concept in many ways.

I don't know is super-res techniques can be applied to bushbroom cameras at all. Framing cameras, sure, but pushbroom - I don't know. You'd have to map-project before you stacked, so at that point I think you're already working with 'pixels' that never existed anyway.

Good news: Exploratorium may be back up and running. Trying it out now; fingers crossed.

Just had an email from the Exploratorium webmaster telling me that things should be up and running over there again :-) Probably a whole load of files in one monster folder, but good to be catching-up...

A whole bunch of old images and two new ones (that I noticed) are through. The new ones are from the 2301 drive:
http://qt.exploratorium.edu/mars/opportuni...0M1.JPG?sol2301

"You'd have to map-project before you stacked, so at that point I think you're already working with 'pixels' that never existed anyway. "

Doug is right about this, but the situation is not hopeless. I would work just with a small area, not a gigantic full frame. OK, so I have several HiRISE images of the same area, preferably a flat area so relief distortion will not be an issue. I would enlarge each image before doing any reprojection, so I'm not losing any information by reprojecting. When they are all perfectly registered I would sharpen them a bit and combine. The enlargement is done for super-resolution anyway, by factors up to 10x, so the only difference is the geometric reprojection, and as I say if you reproject after enlargement no information is lost. Tim Parker has a good description of the method somewhere, should be easy to find. I used it with Voyager images of, among other things, Hyperion.

You can do some interesting experiments with this technique by taking one high res image and subsampling slightly different crops of it - copy a 200x200 selection from several locations shifted by just 1 pixel each. Copy each one to its own file, and downsample it to 100x100 pixels. Now you have several different images all copied from the same source but from slightly different locations. Enlarge each one back to 200x200 using nearest neighbour interpolation and look at small details - they are sampled quite differently. But using super-resolution recombination you can get quite close to the original image.

Anyway, no reason why it would not work with HiRISE. Maybe I'll have a go.

Phil

You might select an area where we already have ground truth imagery and a wide range of < 1.0 meter objects to inspect the lower boundaries of the improved resolution. Possibly the cobbles around the rim of Victoria.

I'll pay your Starbucks bill for that day.

dang, that sounds like work.

Work? If it was work I'd be trying to get out of it.

Phil

No updates the last three sols, at JPL or the tracking site, did one of the orbiters go into safe mode again?

It was mentioned on Twitter that ODY is in safe mode.

I feel like I'm danger of forgetting how to do MER image processing it's been so long since I've had any time to do any! Here is a very quick go at the sol 2300 drive direction mosaic to try and help me remember the procedure.



James

You still have not lost your touch!

James' image looked so sharp I thought I'd have a Stooke-ish look (5x) at the horizon and begin the hunt for Cape York.

So could this be it? It's roughly about where Stu and I both predicted it would appear (the bump on the right appears to be an artifact of James' stitching of the pan.) The rise above the horizon looks clearest in the L2 image which I have included without rotating so as not introduce any pixel flutter whatsoever. The slight color difference from the foreground sand is compelling.

VERY good eyes, Dan... looks like a good candidate for Landfall to me.

I'm a bit sceptical, since there are similar "bumps" to the left in the L2 image. A big dune perhaps? Let's definitely keep an eye on it.

My own gut instinct is that we will see York sooner rather than later...

No, I don't think this bump is in quite the right place, it would line up with the very north 'shore' of Cape York the high points of the cape should appear further to the right. There are a few large ripples 3-500m along that azimuth, one or the other of those would be my guess as an id.

James

Ah Thanks - Being a newby lurker I didnt dare ask ...
Mike

More sol 2301 pics are finally at exploratorium:
http://qt.exploratorium.edu/mars/opportuni...0M1.JPG?sol2301

A big bunch of pictures were downlinked a few hours ago. That means ODY is out of safe-mode and back to business.

And let me paste here one of the last entries from Scott Maxwell's twitter here: "Wrote the probably-final version of our 30% drive-speedup experiment. We're on track to try the experiment Friday."

What the...???
http://qt.exploratorium.edu/mars/opportuni...2M1.JPG?sol2301
http://qt.exploratorium.edu/mars/opportuni...2M1.JPG?sol2301

It appears in both L2 and R2 frames! DD at Meridiani?!?

Here's the average of the L2 and R2 frames, then contrast stretched a bit:
Click to view attachment

Yup - I think that's our first obvious Meridiani DD

If you flip between the two frames, the DD doesn't jump back and forth visibly relative to the Endeavour rim:
Click to view attachment
Also it doesn't seem to extend below the visible horizon. This all suggests that it's really far away, which would mean it's really big.

Maybe this means that to get DD's going here, we need the more extreme topography of Endeavour crater. If we're lucky it'll mean more cleaning events/gusts as we near Endeavour!

A cropped x-eyes stereo view. The dust plume really seems to be very distant, maybe even inside the Endeavour (don't know though if that is possible as to the physical factors involved).

If it were inside endeavour - then it would be utterly utterly enormous. It's probably a KM or two away, no more than that.

"Dust devils"-- cyclonic thermals (Sun heats the surface, warm air rises and the rising bubble of air develops a coriolis spin) occur frequently at Meridiani. They are not as visible as at other places because there is less available dust on the Endurance-Victoria plain due to the desert pavement (armoring) of the Blueberries on the surface.

Depends, of course, on what you mean by "dust devil"-- the visible dust plume or the rising thermal. My opinion is that it is thermal activity that defines.

Attached is an enhanced MOC image of the area SW of Endurance crater showing (faint) dust devil tracks...

--Bill

Thanks Bill -- you've swept away many grains of misunderstanding! So, if a DD travels along a dusty bed inbetween BB outcroppings, it might gain visibility?

Thanks for the info, Bill. I hadn't recalled either ground or orbital images of DDs at Meridiani. (And I do believe this is the first ground sighting.)

As far as the semantics, doesn't it seem that a dust devil should have dust?

Sorry - yes - I should have been more specific - I meant seen from the ground.

Very good. Once we get through the data crunch, maybe we can run some of the DD sequences with Opportunity again. Personally, I've seen terrestrial dust devils, snow devils, and trash devils. So count me among those who give meaning to the word "dust" and do not mean "vortices". However, it is not obvious there is vorticity in the image. It has sort of the right shape, but still could be a gust. Hmm, more imaging, definitely.

We did see dust lifting by gusts within Victoria. Definitely no dust devils, but still some dust gusts--not like this, though.

It may be a semantical distinction, but given that we can have (as noted) "terrestrial dust devils, snow devils, and trash devils" the common factor is not which disturbed material was making it visible, but the convective motion of the air.

With Spirit we developed the software routines to detect and image dust devil-specific events, which could be used here, too.

--Bill

(raises hand meekly from the back of the class)

What about an impact? Might that be a cloud of dust dispersing after a small meteorite whumped into the plain up ahead?

Just thinking outloud, don't look at me like that...

In the meantime, new colourised pan here...

http://twitpic.com/284kwe/full

From such a distance, it does look a bit wide compared to the little DD's imaged from Spirit's locale...

...and in widescreen-o-vision...

Click to view attachment

Here's another view of dd tracks at Meridiani - a CTX image with Endurance at the middle. Image number is in the file name.

Phil

Click to view attachment

Very good, Phil. I've been needing to avaliable images to locate other DD tracks in the area.

Here is an earlier image to compliment the MOC image I posted yesterday. It adds an element of time in the DD tracks observation.

--Bill

I agree that inside Endeavour is unlikely for this DD. But looking at this image, it appears that there's something of a "dust devil alley" to our east-northeast, beginning roughly around mini-Endurance:
Click to view attachment
The sighting on sol 2301 was looking almost directly east, straight into the alley. If the DD was at the near end of the visible DD alley, around 3.5 km away, it would be about 50 metres wide, which sounds believable from what I recall of Gusev devils.

Hopefully this means things will get gusty as we approach mini Endurance. I suppose it's not entirely clear if this "DD alley" really gets more devils due to topography, or if their tracks are just more visible on the surface there for some reason.

Rover Heaven. Ground as flat as a parking lot, and frequent gusts to clean off the solar panels.

But like watching a film where everything is going just a little TOO well for the hero, I keep getting an ominous feeling that the evil Dr. Entropy is lurking somewhere just out of view to thwart our quest.

I have a question regarding Mini Endurance.

From all the images we have of the hills of Endeavour Crater and the road ahead to it.
Can anyone show in those images what direction Mini Endurance is?
I wonder if we can see any part of Mini Endurance yet like a raised rim? Will she have
the same look Endurance had when we approached her eons ago??? I think it would be
fun to be the first person to spot her.

I would also like to say thanks to all the Image Experts in UMSF for doing an
awesome job and look forward to the amazing images to come as we get closer to
Endeavour Crater.

Thanks,

The Quiet One Bobby.

Good question, Bobby. I estimate mini Endurance/Santa Maria should be in very roughly the middle of this frame:
Click to view attachment
It should appear very roughly as wide as the white bar. No obvious signs yet, but we'll certainly have to keep our eyes open.

It does seem to have something of a raised rim, maybe similar to Endurance, so it should be visible from a good distance.

(Maybe this should be in distant vistas, although Santa Maria is becoming a relatively nearby destination...)

From where we are at now. How far away are we from mini Endurance/Santa Maria???