IPB

Welcome Guest ( Log In | Register )

72 Pages V  « < 68 69 70 71 72 >  
Reply to this topicStart new topic
Getting Unstuck in West Valley
fredk
post Nov 3 2009, 04:38 PM
Post #1036


Senior Member
****

Group: Members
Posts: 3156
Joined: 17-January 05
Member No.: 152



Speaking of long-term monitoring, something caught my eye about the latest rhazcam frame from sol 2072. At first I thought the rover had shifted a bit counter-clockwise between 2072 and the previous frame, 1998. But then I noticed that the entire frame, including the underside of the solar deck, shifted to the right. So it doesn't look like the rover shifted, but instead the rhaz camera itself rotated slightly towards the left (counter-clockwise from above) by sol 2072. I would've thought the camera was mounted pretty snugly, so this is surprizing.

Here's an animation showing the movement. You can tell it's not a lighting effect by concentrating on the silhouettes of features against the bright sky:
Attached Image
Go to the top of the page
 
+Quote Post
Hungry4info
post Nov 3 2009, 04:48 PM
Post #1037


Senior Member
****

Group: Members
Posts: 1011
Joined: 26-July 08
Member No.: 4270



I confirm.

In a few Sols, the camera may be laying on the ground, conveniently aimed underneath Spirit laugh.gif

Wait... that's not a good thing wacko.gif


--------------------
-- Hungry4info (Sirius_Alpha)
Go to the top of the page
 
+Quote Post
djellison
post Nov 3 2009, 04:54 PM
Post #1038


Administrator
****

Group: Chairman
Posts: 13731
Joined: 8-February 04
Member No.: 1



I have tweeted the appropriate people smile.gif

One could explain the solar array moving with wind - but not the whole scene. Perhaps strong winds have been moving the rover around ever so slightly and the array as well. 120deg FOV on Hazcams - a 3 pixel shift would be the rover moving by 0.3 degrees.
Go to the top of the page
 
+Quote Post
Hungry4info
post Nov 3 2009, 06:34 PM
Post #1039


Senior Member
****

Group: Members
Posts: 1011
Joined: 26-July 08
Member No.: 4270



So, if nothing else works, by sol 20,000 we should be out of here? rolleyes.gif


--------------------
-- Hungry4info (Sirius_Alpha)
Go to the top of the page
 
+Quote Post
ilbasso
post Nov 3 2009, 06:56 PM
Post #1040


Member
***

Group: Members
Posts: 752
Joined: 23-October 04
From: Greensboro, NC USA
Member No.: 103



I think you're on to something. If we wait a couple of billion years, the ground will erode out from under Spirit like it did for the Meridiani meteorites. Then we can just drive away with impunity.


--------------------
Jonathan Ward
Manning the LCC at http://www.apollolaunchcontrol.com
Go to the top of the page
 
+Quote Post
bgarlick
post Nov 3 2009, 07:28 PM
Post #1041


Junior Member
**

Group: Members
Posts: 53
Joined: 5-October 06
Member No.: 1227



fredk is right, It does not look like the rover is moving, but rather that the camera is turning. Since the shift corresponds to how bright the surroundings are is it possible that thermal expansion is causing the camera mount to twist to one side? (Under recent darker, colder, conditions is the shift not as pronounced?) If the shift has been monotonically increasing over time then that might indicate seasonal temperature changes or something unrelated to temperature... (what else could cause the camera mount to shift? I doubt wind could, and wind would not cause a monotonic increase)
Go to the top of the page
 
+Quote Post
Hungry4info
post Nov 3 2009, 07:40 PM
Post #1042


Senior Member
****

Group: Members
Posts: 1011
Joined: 26-July 08
Member No.: 4270



QUOTE (ilbasso @ Nov 3 2009, 12:56 PM) *
If we wait a couple of billion years, the ground will erode out from under Spirit like it did for the Meridiani meteorites.


A great idea! But if that rock under Spirit is sturdy, then by the time the ground significantly erodes, Spirit may be trapped further. Maybe she'll be up at enough tilt to get some traction though. How would the rock scraping up against the underside of Spirit fare on the rover's health in such a situation?


--------------------
-- Hungry4info (Sirius_Alpha)
Go to the top of the page
 
+Quote Post
Astro0
post Nov 3 2009, 10:39 PM
Post #1043


Senior Member
****

Group: Admin
Posts: 2805
Joined: 21-December 05
From: Canberra, Australia
Member No.: 615



I've noticed these 3-4 pixel wabbles before. I'd have to get back to my other computer, but I did an animation once using Navcam images looking at the layers in HP and the presumably fixed camera position moved by 3-4 pixels during the course of about 30 images.
My thought at the time was as temperatures changed throughout the day that either the soil or parts of the rover itself were expanding and contracting slightly changing the cameras position. That was my theory at least, but perhaps the explanation lies elsewhere.
I'll find that animation and post it later.
Go to the top of the page
 
+Quote Post
djellison
post Nov 3 2009, 11:09 PM
Post #1044


Administrator
****

Group: Chairman
Posts: 13731
Joined: 8-February 04
Member No.: 1



Scott's going to have a look at it.
Go to the top of the page
 
+Quote Post
fredk
post Nov 3 2009, 11:10 PM
Post #1045


Senior Member
****

Group: Members
Posts: 3156
Joined: 17-January 05
Member No.: 152



It's a lot easier to imagine a variety of things causing the navcams way up there on the mast to drift around a bit. But hazcam really surprizes me. Bgarlick's idea of thermal expansion could be an explanation though.
Go to the top of the page
 
+Quote Post
ElkGroveDan
post Nov 3 2009, 11:24 PM
Post #1046


Senior Member
****

Group: Admin
Posts: 4657
Joined: 15-March 05
From: Sloughhouse, CA
Member No.: 197



Is it possible that the hazcams are attached with some kind of gasket for vibration dampening that could be expanding and contracting after so many thermal cycles?


--------------------
If Occam had heard my theory, things would be very different now.
Go to the top of the page
 
+Quote Post
Astro0
post Nov 4 2009, 12:42 AM
Post #1047


Senior Member
****

Group: Admin
Posts: 2805
Joined: 21-December 05
From: Canberra, Australia
Member No.: 615



I'm just having another thought about this apparent movement in the Hazcams. I think that there is also a tiny movement in the left Haz images as well as the right. Maybe not as pronounced.

Just looking at the timing between these frames, perhaps someone with more time could check, but did this movement occur in the interval when they were testing whether one of the middle wheels was jammed. Didn't they do a quarter/full wheel rotation at some stage?
Perhaps this motion moved the rover a little.
Go to the top of the page
 
+Quote Post
Tesheiner
post Nov 4 2009, 06:40 AM
Post #1048


Senior Member
****

Group: Moderator
Posts: 4275
Joined: 19-April 05
From: .br at .es
Member No.: 253



QUOTE (Astro0 @ Nov 4 2009, 01:42 AM) *
Perhaps this motion moved the rover a little.

Maybe, but I think we are here dealing with a movement of the camera relative to the rover itself, isn't it?
Go to the top of the page
 
+Quote Post
djellison
post Nov 4 2009, 08:09 AM
Post #1049


Administrator
****

Group: Chairman
Posts: 13731
Joined: 8-February 04
Member No.: 1



QUOTE
MarsRovers
@doug_ellison team thinks it could be due to slight settling after diagnostic tests on 1916, 1933 & IDD work on 1998, 2072. Great catch.


I think Scott's looking at it a bit more closely. If we've discovered that RHAZ DOES move - then there's perhaps implications for generated terrain meshes.
Go to the top of the page
 
+Quote Post
Astro0
post Nov 4 2009, 11:16 AM
Post #1050


Senior Member
****

Group: Admin
Posts: 2805
Joined: 21-December 05
From: Canberra, Australia
Member No.: 615



My brain keeps recalling something I saw in the Navcams which suggested to me some odd movement.
I've tried to find it on my computer but to no avail. Possibly deleted it.

However, going back through the Navcam images I found something similar.
Attached Image


This sequence taken on sol1972 (left navcam) between 13:27.17 and 18:26.41 local time shows the movement which I was putting down to the effect of thermal changes on either the soil or vehicle. The alternative suggested above maybe movement of the IDD or wheel tests - not sure about the activity going on through this sol on that afternoon.

Of course, it could all be a trick of the light, but a giveaway to me is the position of the 'hot pixel' lower right (~1/4 up, ~1/4 from right) which stays in place while the background shifts.
Go to the top of the page
 
+Quote Post

72 Pages V  « < 68 69 70 71 72 >
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 22nd August 2014 - 09:38 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.