Wonders if the exploratorium site is down again.... no images posted despite them being received on Earth. (Spirit too)

It seems that the site (or the JPL server to which they connect to) doesn't update its contents hourly. There is now (08:00 UTC) a big lot of images from current and previous sols both for Oppy and Spirit.

BTW, the rover has reached the "Four Lane".

The rumors of Oppy's demise are greatly exaggerated. Microcraters, crossbedding(?), a way into Erebus (??) and more. It's 3AM, and I had to get up and take a peek...

--Bill

Yikes.......where will Opportunity go from here?

http://qt.exploratorium.edu/mars/opportuni...00P2400R2M1.JPG

I think thats the monster dune that's been visible for the last several km's.

My bet is first NW, zig-zagging thru the smaller dunes then SW until reaching the outcrop that can be seen near the horizon between the first and second frames on this "post-drive" panorama.

Click to view attachment

Why?
Because there seems to be only two possible routes from here. Either S (and hoping to find a way thru the dunes) or NW then SW. I voted for NW since some time ago, but this pano seems to confirm it.
Usually they take a so called "post-drive" set of pancam images in order to plan the following drive(s). And the mean heading of this panorama is about NW; it's not looking south.

But first, I believe Oppy will (should) head south to have a look to that big outcrop already referred by Bill Harris.

Recent images with exposed rock below the dunes reveal a surface that appears very fractured (and weathered?). Does this have to do with the adjacent crater impacts, a result of water, or other causes? In addition, there appears to be no debris from the meteor impacts, why is that?

I love to approach them. They are good places to catch winds. They help to channel winds by their mini-valleys walls.

Yes, it is possible to climb on them only by starting on the smooth slopes and advances always on the gentle slope up to the mini-summit. almost sure, on the mini-summit there will more breeze than on the bottom.

Rodolfo

Oppy is at the rim of a very old impact crater. Notice how the layering in the "pavement" rocks is no longer primarily flat -- it's all jumbled, with adjacent pieces of rock showing far different orientations in the layers.

The pavement rocks here are the remains of the jumble of ejected rocks created when Erebus was formed. It's all been weathered down to nearly flat, and then covered over with dust drifts... but this was all once the rocky, jumbled ejecta from Erebus.

What I'm *really* interested in is the dark rock unit that seems to underlie the evaporite unit, as seen in the Mogollon and Vermillion Rims (and also in a smaller outctop of the original crater rim fairly close to our current position). I'm thinking that this is rock from the unit that underlies the evaporite across this entire area, and it will be *very* interesting to see what was here before the seas came and went.

-the other Doug

Anyone else notice the macro-crater in the ripple in the top left of the image Sunspot linked? It is a little larger than the mini-craters we've been seeing so far.

A lot of work needed, now seems Oppy completely avoided big dunes following north trajectory.
I'm absolutely not sure about Sol618 location (very few features visible), so any suggestion/help is welcome!

I think she went north from point n. Slightly west but basically north. If you look I think there's some duplicate bedrock features between the west end of your map and the edge of the bedrock north from n, if that makes sense.

mhoward is right. The small roughly triangular area of rock just above 'o' is also shown at the upper left corner of the mosaic section above 'n'. If the newest section of the mosaic is shifted to the northeast it will be corrected.

Phil

Dilo, your last mapping position of Oppy is correct. I have checked navcam from Oct 20, 2005. Now she is heading toward south according to the forward hazcam (bottom of pictures looks the big ripples) and rear hazcam (the bedrock ends).

Rodolfo

This is my projected route map for Oppy over the next few Sols. The dotted Blue line was the first guesstimate of the probable path from a month back, the dotted Red line is the confirmed path (usually per Dilo) and the dashed Blue line is my current guess on Oppy's route for the next couple of Sols.

I think she will go to the south end of the FourLane outcrop and examine the different bedrock exposure there and then head north and west around the dune area.

--Bill

Dilo,

About sol 618, here below is your route map with some annotations (in green) following mhoward and Phil Stooke comments.
You will also find another annotation regarding sol 616 position for which I already made a previous comment; it's lost somewhere among all yesterday posts.

Click to view attachment

Edited: That previous post is here.

Thanks for your helping efforts! I will implement all corrections in my next map.
Now I'm preparing images from Sol618/619, to be stitched, reprojected and joined... is a slow/delicate job, while now Oppy is sending 2 panoramas each Sol!
So have a little patience, pls.

Now map seems ok, but... where the hell is going Oppy?!?
Can someone explain to MER people that Erebus is to South?
Very strange strategy , can someone explain it?

Dilo, Oppy is following a projected path closely. Attached is my "guesstimated" route and as can be seen, Oppy is traveling northward and around that dune complex. This is going to be a difficult part of the journey since she will have to thread a path between a dozen purgatory traps.

I've added an image taken a couple of Sols ago that is looking northwestward and shows the projected path around a low dunefield north of the big dunefield (edit).

--Bill

The change of strategy of route is probably to avoid the big ripples. I seems like that the Oppy will circumven these big ripples following around the projected blue lines from Harris's picture.

It seems like that the Oppy drivers has no exprience of dunes' driving and hence his driving style is of risk avoidance. On the contrary, the Spirit's rover driver looks like they have mountain hiking's experience so their driving style is realist to MER capabilities.

I think we have missed lots of opportunities to learn more science terms around the Erebus' northen rims.

I have no idea about the exact position of Mogollon rim where Squyers has told in his boletin at Athenea Web page. It looks to be at the southern most rim of Erebus crater?

Rodolfo

Thanks Bill/RNeuhaus, now strategy appear more understable to me...
In fact, looking carefully to Sol619 panorama, there are some higher ripples toward Erebus, evident if we make a vertical exageration (5x, horizontal angle is about 145deg).
Click to view attachment
I traced probable path in order to avoid them but, from the very last images (Sol621) I have impression that there was some further drive toward Nord...

This is an updated "bird's eye" view of Erebus/Victoria complex, containing the updated route map.
Click to view attachment

Rodolfo--

The Mogollon Rim features are named after geological/geomorphological features in the USA state of Arizona. The outcrop "Payson" is named after a town there.

It's pronounced "mow-gee-yon", Spanish pronunciation of an American Indian word.

The Mogollon Rim is on the west-southwest rim of Erebus. An annotated MOC image is attached. I think that the Oppy drivers are being cautious since the sand in these ripples can become treacherous with no warning of bad conditions.

Dilo--

Great use of that ziggy-zag navcam image. Shows where we were and where we're going.

--Bill

Labelled southern Erebus rim:


High Resolution: http://xs48.xs.to/pics/05395/Sol_592_Oppor...90_Labelled.jpg (478 KB)

Whoah..... you can really see how far north they've gone int he latest navcam images.

http://marsrovers.jpl.nasa.gov/gallery/all...RP1655R0M1.HTML

Yes, and based on last pancams I think Oppy will go N (probably NW) even more.

Dilo, I fear that it will be quite difficult to match the vertical projections together without the reference of the outcrops. What do you think?

Until Oppy don't reach the next patch of rock, I will try to pinpoint the rover position based on the headings to that little crater looking west. Here below is a first trial based on sol 621 data (the base image is the same I used some weeks ago when talking about possible paths to Mogollon).

Click to view attachment

The headings can be obtained from pancam images 1P183318548EFF63IRP2406L2M1 and 1P183318548EFF63IRP2406R2M1. That shot was taken with the camera pointed exactly at -90º (info from pancam tracking web) so the headings to the crater rim are: 90 + 2.01º and 90 - 3.07º.
Rover positions using this method may have significant errors, but at least they are not cummulative.

Edited: Simply disregard this post. I've just downloaded the missing navcam images for sol 621, and a quick parallax measurement places that drive on the 15m range -- a half of what I calculated with the headings to the crater.

Thanks to Bill ad SigurRosfan About Mogollon, Payson and Vermillion ubications. Now, the Oppy is heading with a new objective: "reach as fast and safe as possible to Mogollon" This mean JPL gugs are no longer interested to visit any other thing on the way to Mogollon's rim.

According to the previous Erebus's picture, I see that the northern-west sides there are less vertical (North-South) shadow lines. This mean that the land has ripples less pronounced height so that zone would be flatter to traverse before heading to south that would be rather easy travesing by following between valleys that run from North - South.

Rodolfo

I wonder if they will avoid the immediate rim of Erebus entirely? It looks like there may be a smoother area a little way out from the rim which continues south - it appears as slightly darker patches in the picture Tesheiner posted.

Here's a polar pan as requested... I've been too busy to do many lately even though we keep getting these wonderful pans, especially from jvandriel (original author of this one).

This is the 'four lane highway' area. Opportunity is now NW of it.

Notice all the fractures in the bedrock. None of them can be traced very far from outcrop to outcrop. They are perhaps more like joints than faults, small local fractures without a coherent regional pattern.

Phil

Click to view attachment

PS I edited steps out of the horizon before making this.

I'm still wondering why that method to pinpoint Oppy's location didn't word, but couldn't find the mistake. Comments are welcome.

Thanks Phil,

Might I take your polar drawing pictures until when you are back?
What software do you use to create it?
What are the input for this drawing?
Is that rather complicated process or not?

New Oppy's position in polar orientation format. (needs one more recent).

About last Tesheiner's post. What I pay the attention is that the value of 90 degree, the horizontal line going to EAST is not valid here unless it is officially stated. If it is official, then we can start measure the angle from here as good reference.

RNeuhaus, look here:

http://www.unmannedspaceflight.com/index.php?showtopic=1075

for a description of the process.

I was not quite sure what your first question means. You are welcome to use anything I post here.

Phil

It seems Oppy covered a very long distance on Sol 621. I updated the MGS image using last one taken on 5 October (more detailed).
As feared by Tesheiner, precise identidication of Rover position in the satellite map isn't easy, i tried to do my best but for sure is not precise...

That 90º value was taken from the MER Pancam Data Tracking Web Interface and more then official it can be considered "internal" (or technical) information.

That was the heading programmed to the pancam when taking the first of four shots of what is usually called "drive direction panorama". -1.57071 is the heading in radians; look it yourself and you will see a series of four shots, the first pointing at -90º and the next three ones with a clockwise added delta of 13.333º.

---
Expected EDRs by sequence number and image type:

Sol Seq.Ver ETH ESF EDN EFF ERP Tot Description
--- -------- --- --- --- --- --- ---- -----------
621 p0755.03 10 0 0 10 0 20 navcam_5x1_az_270_3_bpp
621 p1212.02 2 0 0 2 0 4 front_haz_ultimate_2_bpp
...
621 p1600.01 20 0 0 20 0 40 navcam_10x1_az_0_1_bpp
621 p1655.01 10 0 0 10 0 20 navcam_5x1_az_90_1_bpp
621 p2124.03 3 3 0 0 1 7 pancam_cal_targ_L456
621 p2406.06 8 0 0 8 2 18 pancam_drive_direction_4x1_L2R2
...




Summary for: bp2406.06a.pancam_drive_direction_4x1_L2R2.rml:

ETH ESF EDN EFF EHG ERS ECS ERP Total
---- ---- ---- ---- ---- ---- ---- ---- -----
8 0 0 8 0 0 0 2 18

Duration (hhmmss) = 00:10:43
Data Vol (Mbits) = 24.28

---------------------------
bp2406.06a.pancam_drive_direction_4x1_L2R2.rml:
---------------------------
cmdname pri id img hist rsum csum ref lcam rcam frm c1 c2 c3 frmarg lflt rflt acq shut exp lscl rscl lexp rexp ltbl rtbl updt thres pxfrc iter perc bdpx flat subf rstrt cstrt nr nc dwnsmp ph pw pxscl comp bpp minls wfilt ndcmp nseg
RUN_FILTER_POS LPAN 7
RUN_FILTER_HOME LPAN CCW
RUN_FILTER_POS RPAN 7
RUN_FILTER_HOME RPAN CCW
CAPTURE_IMAGE 26 1000001 TRUE FALSE FALSE FALSE TRUE LPAN RPAN LVL_AZ -1.57071 -0.09599 0.0 NA PANL2 PANR2 LIVE COND AUTO 1 1 50 50 ARG ARG TRUE 2500 1 6 10 FALSE FALSE NONE 0 0 1024 1024 NONE 1 1 NONE ICER 3 0 A 4 20
CAPTURE_IMAGE 26 1000002 TRUE FALSE FALSE FALSE FALSE LPAN RPAN LVL_AZ -1.33806 -0.09599 0.0 NA PANL2 PANR2 LIVE COND AUTO 1 1 50 50 LPAN2 RPAN2 TRUE 2500 1 6 10 FALSE FALSE NONE 0 0 1024 1024 NONE 1 1 NONE ICER 3 0 A 4 20
CAPTURE_IMAGE 26 1000003 TRUE FALSE FALSE FALSE FALSE LPAN RPAN LVL_AZ -1.1054 -0.09599 0.0 NA PANL2 PANR2 LIVE COND AUTO 1 1 50 50 LPAN2 RPAN2 TRUE 2500 1 6 10 FALSE FALSE NONE 0 0 1024 1024 NONE 1 1 NONE ICER 3 0 A 4 20
CAPTURE_IMAGE 26 1000004 TRUE FALSE FALSE FALSE FALSE LPAN RPAN LVL_AZ -0.87275 -0.09599 0.0 NA PANL2 PANR2 LIVE COND AUTO 1 1 50 50 LPAN2 RPAN2 TRUE 2500 1 6 10 FALSE FALSE NONE 0 0 1024 1024 NONE 1 1 NONE ICER 3 0 A 4 20

---

A 31.8m drive Dilo?
If that's correct (and it looks like) my last attempt to pinpoint the rover position was successful. I will continue doing that.

That is plausible. Evidently Opppy is taking a long run up a ripple trough to get around the loose sand north of that last dune complex. I fear that we won't have much to go by for post-drive route positioning; the only landmarks are that lone small crater to the West and whatever Erebus features we can triangulate back to. Dilo and Tesheiner are doing the best with what they have to work with.

Here is my current route chart; I think that Oppy will soon turn back around and head Southwest toward the Western rim of Erebus.

--Bill

I did another exercise to locate Oppy position (sol 621) and here are the results. In a glace, it confirms my previous attempt just checking for that small crater.
On this new attempt I used the headings to the following points:
A - Crater to the west
B - Bright outcrop (probably the next waypoint on Oppy's route)
C - Mogollon
D - Oppy's previous position

Click to view attachment

The basis for calculating the headings to those significant points was jvandriel's panorama for that sol (on Erebus thread), here below with some annotations, but if you really want to see that features I suggest to use the original navcam images.

Click to view attachment

Dilo, a comment to your route map.
Have a look to my proposed position for sols 619 and 621 and compare with the ones on your map; there is a significant difference on the headings. The rover tracks on your last map are positioned at about 30º NNW while on mine they are at about 7º -- nearly north. I'm now quite confident of that positions and it looks like the reason for that discrepancy on the headings is that your map is accumulating errors.

Do you remember that discussion on the Spirit Route Map thread about the methods to plot a route map?
The stitching of sol 621 vertical projection on the map is very good, but day after day such a process propagate its small errors to the future. I have the impression that the map is a bit rotated counter-clockwise.

Polar Projection of the sol 621 pan. Be gentle it's my first one. I have finally finished my MA Dissertation (submitted yesterday) so have time to learn some p'shop, PTgui, Autostitch etc... skills.

Bows head to the master image processors who inhabit this board. I have some catching up to do.

Thanks Paxdan : nice (and funny) image !
Wow ! We are no more on Mars : this is Dune !
Now, be careful for rover moves, please.
Some giant worms may be around...

paxdan - nice one! If you add a bit of white space at the bottom of the pan before you do the polar projection you will avoid that over-compressed impression at the centre.

Phil

Thanks Phil, here is a modified version which has also been pinched to alter the perspective.
Click to view attachment

Paxdan, Good work! Thanks to Phil to share his knowledge of that technique.

Rodolfo

Tesheiner:

That is a unknow terrain, about the engineering commands, for me!

Hope that is good information to guide us about the orientation of rover.

However, do you have any manual guide to interpret these commands and their parameters?

On the other hand, these instructions, some are intuitive to interpret the meaning of the execution of the command. Thus, I would like to have a guide manual about these instrucitons in order to understand them.

Back to your question, so we can take the the rover position after identifying some visible positions as you have suggested at the previous post. With four reference position is more than enough. I think that the minumum is 3 for a good ubication trace.

Rodolfo

Rodolfo

Probably you are right, even if I'n not sure heading difference is so big.
I already suspected something wrong looking to ripples orientation (which is no more NS as usual in the last projections), but alignment with distant outcrops seemed good.
In the past, I periodically corrected these orientation issues through comparison with MGS image, now I definively need a more precise method but I'm not sure which is best...

Dilo - one option is to use an extreme enlargement of the MGS image as a background. As you add each of your reprojections, match it as well as possible to the background image. This will help to prevent errors accumulating across the image. It would be what is called a semicontrolled mosaic.

Phil

Thanks Phil, in fact I was considering this option... However, this method do not solve issues in very uniform patches like the present one. Here I must use also some kind of distant well known referring point (like the small West crater already used by Tesheiner); otherwise, I should go to MER Pancam Data Tracking Web Interface (I must admit this last option worries me because interpretation do not seems easy !).
I will implement at least one of these methods in my next route... promised!

Another suggestion...

You can use a polar projection to obtain the best alignment to those reference points and then make the vertical projection maintaining the same heading but slightly moving it on the x and y axis to find the "best fit" with your current mosaic.

Anyway, and while Oppy is moving on this "sea of dunes" I will continue to double-check the rover position using the headings to known points.

Sol 624 - New official traverse map (462 KB):

http://shoreline.eng.ohio-state.edu/album/...003/opp_624.jpg

Official map and still incorrect. It is off by about 20m to the north.
We already commented that fact some time ago (somewere here in this thread).

It is good to have the link to the source of the MER traverse maps but we must take those maps (at least Oppy's) with some care.

PS: At their home page (http://shoreline.eng.ohio-state.edu/) you can find the links to both Spirit and Opportunity route maps.

I think they might be planning to go right around Erebus... driving on the areas in the orbital image that appear slightly darker - these areas appear to have much smaller ripples/drifts, as you can see in this navcam image from sol 624:

http://marsrovers.jpl.nasa.gov/gallery/all...WP0755L0M1.HTML

Alternate route??

Why not go just a little further West and hit some more of the salt flats for quicker traverse?

So maybe we can get back to som old style pedal to the metal driving for a change

This whole experience in the noth Erebus outcrop/dunefield has been a lot time wasting