Great maps! I'm a little puzzled by the slope one though. It seems to show no areas with 0-5 degrees slope, whereas there must be such places, e.g. on the summit of CY and on the saddle joining it to the plains. Is the colour key all shifted by one colour perhaps?

Ah, the perils of posting on UMSF when jetlagged - there are lots of eagle-eyed people out there! Thanks for spotting that mistake on the slope map label, I made it myself and got my numbers wrong, apologies. There are of course quite a few slopes that are between 0 and 5 degrees. It should be something more like this:

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Combining the slope and aspect is a great idea, and I'll give it a go when I get chance.
Pete

"New Consort"...

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I love staring into these surface close-up images and picking out all the different shaped/hued chips and shards of stone...

Second Andy's thanks for the excellent presentation, but agree with him on the desirability of combining slope and aspect data.

My choice would be to keep your hue based aspect information, but encode the slope as saturation, with increasing slope indicated by increased saturation. It would provide a fairly intuitive presentation.

Can anyone suggest an easy way to do that?

SteveM

Sol 2756 360x90 Navcam panorama

left right anaglyph

Hi Steve,

My post #250 would produce one number for each pixel - the "angle from rover-normal to the noon midwinter sun" - and this number (the potential insolation) takes into account the slope and the aspect.

What are the limitations on drivability? Not aspect, so much - we know north is best, but that's subsumed in the insolation. The slope, however, is an issue relating to the stability limits of Opportunity. The steepest slopes are best avoided.

So maybe a more visually useful presentation would be to combine potential insolation with slope.

Say a range of white-green-yellow-red for insolation, and simply black out any slopes over X degrees.

Andy

How about just mapping the northward component of the slope vector? Not as sophisticated as your solution Andy, but maybe easier to do and simpler to understand when done.

Great anaglyph pan mhoward. Eyeball to eyeball with the summit!

Thanks a lot for those maps, Pete. I agree a simple estimate of the northward component of slope is all we really need. There's got to be enough uncertainty in the DEM that too much effort is pointless. This is basically what the team has done before, like this plot around home plate.

The slopes on CY don't look too bad - apart from very small features, the only areas that might be a problem for driving are the east sides of the big "knobs" on the north part of CY, and those are sloping east, so we'll probably ignore them anyway.

Here's a my3D stereo pair for "New Consort". Only so much can be done with L257R2 (as far as I know), but it actually more or less works for me.

I remember registering the color info only from the left channel per Photoshop > copy left image > paste onto right image > left 'top' layer 'layer blend mode' screen > register with select and skew / distort / warp / etc ... > 'layer blend mode' to color I'll try uploading something somewhere..

You can use the stereophoto maker software I linked to to view stereo pairs as wide as you like, either crosseyed or parallel, and without shrinking the images. Click "100" to view at 100% scale, then narrow the window until your eyes can fuse the images. Then you can just drag the images to scroll across.

stereo-rightframecolor-stolen-from-leftframe..

Nice color matching! So small it's blurry in my3D though.

Use the "replace color" feature in Photoshop. Start with the lowest setting, and then replace the next color with that same color, but turn up the saturation a bit, and continue up through the scale.

fixed:)

mhoward's latest pan in circular format...

Phil

Click to view attachment

Very good, Phil-- I was hoping you would post one of your Polar Pans of this latest Navcam Pan.

Oppy is still moving along just to the west of the ridgetop and should be within sight of "winterhaven" within the next driving Sol or two. That site ought to look much like the areas we've seen to the east (our right) the past few days-- light/reddish-toned with plenty of neat rocks and outcrops.

--Bill

Hmm, does this help? I think I've managed to whip Arc into shape enough to do AndyG's suggestion of combining slope and aspect. The perspective view is x3 vertical exaggeration.

Click to view attachment Click to view attachment

I think it's probably showing us what we kind of know already, and probably pushing the helpfulness of the data, but nice nonetheless.

Pete

I've really enjoyed this discussion about ways to map the important data for Oppy's next winter haven choice. I wonder about this, though. Is a simple estimate of the northward component of the slope all we need? What if the northward component is just right in a Goldilocks sense, but the eastward or westward slope component exceeds the stability specification for the rover?

@SteveM: On GIMP, create a gradient with whatever color steps you want, then apply Colors | Gradient Map. On Photoshop it will be Layer | New Adjustment layer | Gradient Map, I think.

For just color coding, it's better to make a color map layer with full colors, then set blend mode to Color and adjust Alpha to get the desired amount of saturation. That way you don't need to fiddle with your base gradient.

It it had a lot of westward component.....it wouldn't be a northward slope any more.

Looks like we're on the top: http://qt.exploratorium.edu/mars/opportuni...2IP0613R0M1.JPG

Thatta girl, Oppy!

Clearer view to the north, definitely, but the good stuff is out of sight, behind that rise over on the right...

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We are following a path left of the "summit".
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Many thanks, Pete. I like that a lot!

Andy

Ah - a chance to examine the light-toned 'flange' around Cape York that we crossed so swiftly at Spirit Point. We're only about a metre below the highest point here so the cameras should just about have a clear 180 degree view across Endeavour should they choose to look that way.

Someone (fredk?) recently re-posted a view of the summit from the vicinity of pathfinder mound. If anyone were so inclined It should now be possible to 'place' the rover at today's location within that view. I think that would nicely put the scale of our recent rovings in perspective.

Would this be the highest elevation yet reached by Oppy? - The rarified air of the Cape York summit?

Since Oppy is in the area underlain by the geologic unit represented at the "winterhaven" and will be spending several months here, for my own accounting purposes I've considered the arrival at "winterhaven" as post- Sol-2754 activities, when we passed the draw informally named "the valley of the shadow".

It will also be great to have time to examine that "onlap area", the contact between the Meridiani rocks and the Endeavour rim rocks (informally called "the Burns Fm" and "the Allen Fm" <G> ).

--Bill

"Would this be the highest elevation yet reached by Oppy? - The rarified air of the Cape York summit?"

No way! It's been downhill most of the way from Victoria crater. Cape York is even lower than the plains a few hundred meters to the west - check out those contour maps just above.

Phil

I believe that the plains that Opportunity drove over to get to Cape York were on average higher than the highest point on Cape York.

edit: What he said ^

Sol 2758 Navcam anaglyph panorama. I'll update this once more images are down.

The latest power numbers aren't great. Ugly trend.

http://marsrovers.nasa.gov/mission/status_...rtunityAll.html

Thanks again, Pete! What do the numbers on the colour scale represent?

In short, yes, that's all we need.

Not sure what you mean by eastward/westward components exceeding stability. The question we're seeking to answer is about power.

-m

I think what he means is something like a West-North-West slope of 40 degrees, as an extreme example. The northward component of that might be about 20 degrees, which might be great for power considerations, but the total slope of 40 degrees might be unsafe for the rover. CosmicRocker, sorry if I am putting words in your mouth!

How are you missing (as Doug said) that if you only have a "north component", you aren't pointing north. As Matt sez you are only interrested in power. Very early on (years ago) there were JPL MER press releases ploting the amount of power a rover would generate in a day with the sun arching over with any particular slope and direction toward the sun. There were pictures of green "lilly pads" (good power) and red zones (bad power). Maybe Matt can drop a power lilly pad JPEG of Cape York on us...

Yeah, I think "north component of slope" is vague. What Andy talked about is probably the best way to go without going overboard. His expression gives the angle between rover normal and noon midwinter sun (I've checked!). Andy: how did you get a "sol" angle of 90 - 57 = 33 degrees? I get sol = Mars tilt, 25 degrees + |rover latitude|, 2 degrees = 27 degrees.

Anyway, this is probably pretty crude, for a bunch of reasons. It treats deviations from the "sol" direction equally whether they're east-west or up-down. It pretends the Sun is stuck at solstice, when it's actually higher before and after. Etc etc. But to do better you'd need a good model to work out the solar power versus angles - that's a job for the jpl guys.

Yes, a deviation in the East/West direction is less harmful than a deviation in the North/South direction, because at least it tracks the path of the Sun.

It's been a long road... getting from there to here...

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Sol 2758 Pancam anaglyph

I'll see what I can do... Currently we're using a single map generated by Ron Li's group at Ohio State. It has been validated by other folks and with various methods, so it's an official tactical tool. Therefore I doubt I could share it due to propriety (or "privileged" information laws). Sad faces, everyone, sad faces...

On the other hand, independently Paolo Belutta has been using a map from the USGS for some strategic rover planning. It hasn't been validated and we don't use it in tactical ops, so I bet usage it a bit more open for the public, and it *is* useful... maybe I'll be able to swing that here. It basically tells the same story as Ron Li's map but with lower resolution.

-m

EDIT:


Well, yes, but we're talking about two independent and different topics, then...

1) The story for northward slope is about power only.
2) The story for total tilt is about stability, etc.

We do keep a close eye on total tilt (and flight software is constantly monitoring it when we drive and do IDD work), but there are no slopes anywhere near us that could tilt us over or make us slide downhill.

-m

I think the concern was more just drivability, rather than something extreme like tilting over! But Duck Bay had slopes approaching 20 degrees, if I recall correctly? According to Pete's maps there's very little in the way of slopes exceeding that here. Of course it also depends on the nature of the surface...

Even a very steep surface could work if the aspect was right and there was a way back up - recall Spirit on the edge of Homeplate. But again the north-facing slopes don't look very steep here.

And here we are. We're there.

This is a panorama of the Sol-2758 Pancam set with the elevation exaggerated 3x. Note the light-toned Cape York weathered area in the foreground, with the ridgetop on the right. The Meridiani upland is in the background with the onlap/contact area in the midground. Of interest is a draw in the right background, located north of Cape York.

--Bill

Just posted an update on the route map thread. Looking to the bedrock we're on right now, I think the actual position on the map will probably be slightly to the left / west but we should wait for the navcams which are planned for tomorrowsol.

Doh! You're quite correct.

I was fiddlin' with my vector maths and googled (what I thought was) Opportunity's latitude. It turns out the result I acquired ("eight degrees south") was the centre of an orbital photo of the landing site!

I shall naturally go and kick myself. (Maybe not too hard though, since 6 degrees is still within a percent of max insolation: and the ground truth from the surface compared to the DEM will cover this sort of error and more! <coughs>)

Andy, suitably admonished

Definitely rubble at Oppy's feet now...

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By the way, if you're one of those people curious about how big Cape York is, I've put some new comparison pics on my blog:

http://roadtoendeavour.wordpress.com/2011/...cape-york-again

If anyone's curious why we've drifted to the western "shore" of CY, I think there's a strong clue in the recent updates: They're on the lookout for veins of light-toned material, like we saw near the "shore" after our first drive onto CY.

The favourable slope region is just a day or two's drive to the E or NE, so I guess we've got the time (and power) to see what's nearby. My guess is we'll now explore more of the "coastline" and the interior of CY.

And it looks like there's some bright spots on the Hazcams, so we can hope there are some around.

Since Opportunity is just two degrees from the equator, why is anyone talking about winter? I would think aphelion would be far more significant.

--Greg

People have been talking about aphelion - see this post and others near it.