Gusev! I'll let someone else do this.

Phil

Hurricane Gustav?
(sorry, I couldn't resist)

Now seriously and back to the main topic:

Sorry to be pedantic but I still believe this task must be automated in some way.

I think it’s already clear that what’s needed is a map that characterizes the terrain in terms already known like tarmac, “purgatory”, bedrock, small ripples. This map should also be of a lower resolution than the HiRISE pictures; or in other words, it should reduce an e.g. 100x100 pixels area to a single characterized point, otherwise it looses its purpose which is to allow mid and long-range route planning.

One way to do this task is to slice the big picture in 100x100pix. pieces and to manually compare them with a set of pre-selected types of terrain. Needless to say that such a task would be time consuming and in case it was shared among a number of volunteers the results wouldn’t be homogeneous. What would be classified as “purgatory like” by one might be characterized as “small ripples” by another one.

Another way to do this task could be again to slice the big picture in 100x100pix. pieces and to automatically characterize them.
It was already proposed to use the wavelength of the dunes as an indicator so the mean wavelength of each 100x100 piece could be compared with the mean wavelengths of the reference pieces (tarmac, purgatory, etc.). The mean wavelength could be calculated, probably using FFT, and I think some of the HiRISE images (e.g. the one I use in the route map) have enough dynamic range and S/N ratio to be used for this purpose, but we need someone with experience on this area (I haven’t).

I think it’s worth a try.

Well just to update you on my progress (less than I hoped as I have a lot on at the moment). I'm now able to load chunks of the JP2 into a C++ program and am going to attempt to get it to recognize different ripple sizes, probably with some sort of Fourier analysis.

No promises though, it maybe too hard given for very limited amount of time I have to work on this.

The Mars Express images by ESA are sometimes great in detail..
and I have seen some images made as in "fly over"

Did Mars Express photograph and "3d" the Opportunity area it is currently located..
Or can it do so soon ?

The HRSC on Mars Express has a resolution of only 10m (2m on selected targets), not enough for our current purpose.

Could we take a "Galaxy Zoo" approach and divvy up each chunk of terrain among multiple volunteers? (Judging from the posts on this thread, I'll bet there's a heckuva lot of volunteers rarin' to go). Using Phil's template as a guide, each volunteer makes his ratings, then sends back the data. Multiple volunteers per terrain unit could allow a statistical average to be developed for each terrain piece.

(And like the "Galazy Zoo" approach, a training set could be used for training, and for validating that the volunteers are ready.)

-Mike

Not in the kind of resolution needed to actually see and characterize the ripples. For that, you need the HiRISE camera. (At least, if the MEX cameras, even the HRSC, can image something as small as the ripples in enough detail to do a stereo image that gives you the size and extent of individual ripples, I'm certainly not aware of it...)

-the other Doug

Those who suggested that clickworkers was the closest analogy were correct. Basically you just need an "impassible dune" cursor for image markup. Galaxyzoo and stardust@home are similar, but galaxyzoo doesn't use clickable images and stardust@home allows a single click on a movie.

I certainly hope that you, like Rui, decide it's funny, Stu. It was definitely intended to be.
Seriously though, you two are far and away the most poetically inspired and poetically eloquent members at UMSF, and I would love to see the outcome of a period of collaboration between you, in giving expression to the spirit that pervades this forum. The desert island is only one idea for a venue, and comes to me because I can see out my window a perfect example in Mokoli'i floating serenely in Kaneohe Bay. There is exactly one coconut tree on the island, in case you need to settle any 'artistic differences' at ten paces.

Unsharp masking could be useful for the chunks:

GIF format

Don't worry, just kidding, I thought it was really funny.

Not as funny as Rui's follow-up sketch... that had me chuckling all day during a rather challenging and not-exactly-laugh-a-minute Course about constipation and caring for terminally ill patients (and you lot all thought my life was full of poetry and martian daydreaming, eh?)... god, we'd be like a space geek version of "Withnail and I"...!!!

Bundling up comments on several posts plus my own ramblings; apologies for the length.
It seems support is emerging for two approaches:
1. software automation

Pros:
• Can probably be made to work effectively;
• Spits out normalised data set covering as large an area as you like in two minutes flat. (To a first order of hand-waving anyway )
• Easily testable, reproducible, and improves over time as the author tweaks the algorithms

Cons:
• dev lead time. It may take some time before the first useful two-minute run!
• only a few people here have the code-fu to do it, a single-point-of-failure. FSM forbid James falls under the proverbial bus just before the first release in a month's time, but...
• lots of possible algorithms that could be combined in various ways, with various parameters and feedback loops, make it easy to try lots of variations and select the best.

2. A Mechanical Turk, human-driven distributed process. (several variants on this have been suggested.)

Pros:
• enables lots of people to contribute
• very quick and simple to kick off (a completely manual version could start in 10 minutes time.)
• the raw data could be straightforwardly fed into software (from 10 lines of Perl, to full-blown C++ GUI apps) for further processing and display in various styles.

Cons:
• indeterminate runtime. Might take weeks, or (pessimistic assumptions) five people, managing one grid square per week, works out to roughly 25 years! (OTOH,.. we could prioritise the closest areas of terrain - a bit like a chess algorithm, in fact, selecting and pruning a tree of possible future moves... )
• Once certain parameters are set (e.g., grid square size, the particular archetypal images are used for the classification cheat-sheet, etc) they can't be altered without junking whatever data set's accumulated to date.
• People make mistakes and/or differ in interpretations. (A training stage would take time to build.)

I suggest that we do both. There's no reason we couldn't start on a Mechanical Turk process whilst the bit-twiddlers do their thing; at some point (a week, two, ten,..) the software's results become more useful than the manual ones, and the baton is passed. A purely manual process could start whilst work is underway on a web-based, semi-automated, galaxy-zoo type solution, AND a dedicated program to do the whole thing.

I hate it when people say this in email at work, but as I've already used the word "solution"... ... "thoughts?"



Correct me if I'm wrong, but my impression is that all the dunes encountered on the way to Victoria had the same angle of repose, so the visible width has a linear relationship to cross-a-bility.


$wine{'cava'}->spray("nose");




Question: which part of Endeavour? I've been assuming your aim point is the jagged western rim peaks; is that right? Is there a definite aim point, or a defined area to aim at?

Here's my rudimentary attempt at showing a proposed track. For more detail at the "points" of interest, zoom in on the HiRISE image at:
http://marsoweb.nas.nasa.gov/HiRISE/hirise...SP_001414_1780/

At this point I don't seem much merit to tracking beyond the giraffa camelopardalis, except in very general terms. ...lots of options.

Thank you, Paolo, for clearly stating your wishes, and thank you Oersted, Imipak, Tesh, Phil and the others who have made clear, practical contributions to fulfilling those wishes. An area map of favorable and unfavorable terrain for Oppy (especially if it can be generated by automated software) will be a major contribution to planning the course of rovers in this and other missions. I have no expertise in this higher order image processing, but I would hope that a way could be found to include points of scientific interest - e.g. craters and cobble clumps - as map features so that a planned track can incorporate them, if the PIs judge them to be worth closeup examination. It is probably too complex a task to automate selecting points of interest, but I would be willing to manually circle any such features I could resolve in a HiRISE mosaic. Points that are isolated by impassable ripple zones could be easily bypassed in preference to those lying in 'safe' zones.