HiRise Imagery of Opportunity's trek, ...or, a blast from the past Options

[CosmicRocker]

Like a lot of people, the new HiRise imagery has had me scrambling to learn about JPEG2000 (jp2) files, and trying to find software and plugins for manipulating and editing them. A lot of that discussion has been taking place in the MRO 2005 topic. We now have two MRO passes providing amazing stereo over much of Opportunity's trek, and it sounds as if we will soon have some Spirit coverage. I can hardly wait for that.

Anyway, I'm starting this thread for anyone wanting to post new HiRise imagery of places Opportunity has explored in the past. I'll start it with an anaglyph.

Even though Meridiani is pretty flat, the MRO images were so fine that I really wanted to see how much detail I could get from them. Spectacular Victoria has already been nicely done, so I had to look elsewhere. I thought Beagle Crater and the transition to Victoria's annulus would be of interest to some people. I'll post this as a jpg that fits the forum size limit, but should we sometimes use the better jp2 format even though all users may not be prepared to view them?

[Phil Stooke]

This is the Payson/Mogollon area of Erebus.

Phil



I would not use JP2 fo regular forum posts. It would be a serious problem for most users.

[ElkGroveDan]

Purgatory is the light spot at the center of this image. Tracks coming in are more visible than those going away.

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[dvandorn]

I am struck by the number of 5- to 10-meter circular depression features I can see scattered through the dunes, both in the Payson view and (especially) in the Purgatory view linked above.

I'm not as familiar with the full panoply of drift structures as some others here -- are such circular features common in windblown drift/dune structures on Earth? 'Cause these look like cratering remnants to me...

-the other Doug

[climber]

Anyway, I'm starting this thread for anyone wanting to post new HiRise imagery of places Opportunity has explored in the past. I'll start it with an anaglyph.

It's very nice looking. Nevertheless, as on Doug's anaglypk of Victoria, it seams MUCH deaper than it is. Anybody can explain this ?

[climber]

Purgatory is the light spot at the center of this image. Tracks coming in are more visible than those going away.

Ah ah ah ElkGroveDan, after been a Beacon specialist you've turned to be a Purgatory specialist now. Not easy to spot, good work (I know, it was Tuvas that...).
OK, we lost this Beacon pool, but what, do we realy need purgatory ?

[djellison]

it seams MUCH deaper than it is. Anybody can explain this ?

Your eyes are perhaps 10cm apart. The two HiRISE observations were probably taken from 100km apart (I'm guessing that figure, but you get the idea) Hence, even if you do the maths for say, the Human eye looking at this terrain from 100ft high, the two HiRISE obs are like UBER stereo vision

Doug

[CosmicRocker]

Here is an anaglyph of Erebus. There is not a large amount of vertical relief here. It's essentially a shallow dish, but things like the monster drifts, the outcrop cliffs, and Payson promontory stand out.


The vertical exaggeration that is apparent in stereo imagery is a function of four variables, including the distance between the orbiter when each image is acquired, the height of the orbiter, the distance between your eyes, and the distance between your eyes and the stereo pair. There is a nice description and diagram on in this remote sensing article.

You'll notice that you have control of one of those variables...the distance between your eyes and your monitor. If you position your eyes very close to the screen, you can reduce the vertical exaggeration. You can increase it by moving away. I find this a helpful way to see small vertical changes. For instance, you can view this Erebus anaglyph from halfway across the room and the monster drifts look like huge dunes from the Sahara. Unless you have the eyes of an eagle, you'll need to zoom the image up to 200-400% original size.

[ElkGroveDan]

Ah ah ah ElkGroveDan, after been a Beacon specialist you've turned to be a Purgatory specialist now. Not easy to spot, good work

Details confirming this location are here

As for the "Battle of the Beacon" there is no shame in losing a great confilct. I try to live by the words of American President Theodore Roosevelt (served 1901-1909).

Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure...than to rank with those poor spirits who neither enjoy much nor suffer much, because they live in a gray twilight that knows not victory nor defeat.

Bring on the next great debate!

[climber]

As for the "Battle of the Beacon" there is no shame in losing a great confilct. I try to live by the words of American President Theodore Roosevelt (served 1901-1909).
Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure...than to rank with those poor spirits who neither enjoy much nor suffer much, because they live in a gray twilight that knows not victory nor defeat.
Bring on the next great debate!

Oh Yes, I agree! Hope you notice the "we" in my sentence..."OK, we lost this Beacon pool, but what, do we realy need purgatory?". I was definitively on your side and I see that you're not trying something easy by looking after Purgatory. Don't tell me you didn't get the joke

Back on next great debate : anybody found "Bounce rock" ?

[tuvas]

It's very nice looking. Nevertheless, as on Doug's anaglypk of Victoria, it seams MUCH deaper than it is. Anybody can explain this ?

The reason for the depth appearing to be much steeper is that the angle between the points is on the order or 20 degrees (That's from memory, not from looking it up, so...). This increased angle gives the appearence of being steeper than it really is. However, this does allow for a higher-precision elevation map to be made, which is exactly what they want for imaging something like Victoria crater.

[djellison]

VEERRRYYYY rough maths. Altitiude of 278k for one ob, 269 for the other - call it 274 average.

20 degrees, 274km..... the 'eye distance' is about 96km between observations.

Doug

[atomoid]

I am struck by the number of 5- to 10-meter circular depression features I can see scattered through the dunes, both in the Payson view and (especially) in the Purgatory view linked above.........

...especially this 'peppered' section in Erebus:

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[djellison]

The backshell is really getting my attention. The immediate thought from MOC was that the backshell was on the left with the parachute to the right. What appeared to be the parachute it now seems was just the surface disturbance from a very high speed impact of the backshell.....let the gif load for a while, it shows both.

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[Nix]

I've noticed the backshell-impact did leave a bigger scar into the surface than the heatshield..

Nico