Winter Quarters, at Low Ridge Haven |
Winter Quarters, at Low Ridge Haven |
Apr 14 2006, 02:00 AM
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#1
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Member Group: Members Posts: 166 Joined: 20-September 05 From: North Texas Member No.: 503 |
Since Spirit is no longer "Running for the Hills" and it appears that she will be staying at Low Ridge Haven for the next eight months or so, it seems like a good time to start a new topic.
I thought we could start with the great panorama stitched by jvandriel, and then altered by Tesheiner. We are going to become very familiar with this view in the coming months. David [attachment=5107:attachment] (286k) |
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Jun 1 2006, 12:55 AM
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#2
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Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
Very odd.
I see three possibilities: 1) They saw Michael Howards worry about MMB problems if too many image were taken at one site/drive number and decide to help out. 2) They 'tried' to move the broken wheel. 3) They refined there knowledge of Spirits position (there were a number of 'sun finds' at the time of the change) and defined a new site with the new values. I'm not sure I beleve any of these though, a question for Jim Bell I think... James -------------------- |
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Jun 2 2006, 10:34 AM
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#3
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Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
Very odd. I see three possibilities: 1) They saw Michael Howards worry about MMB problems if too many image were taken at one site/drive number and decide to help out. 2) They 'tried' to move the broken wheel. 3) They refined there knowledge of Spirits position (there were a number of 'sun finds' at the time of the change) and defined a new site with the new values. I'm not sure I beleve any of these though, a question for Jim Bell I think... James Right on the money, James! From http://marsrovers.jpl.nasa.gov/mission/status.html: QUOTE SPIRIT UPDATE: Spirit Perfects Pointing Parameters, Collects Images Large and Small - sol 855-859, June 1, 2006:
Since arriving at the rover's current location on the 807th sol, or Martian day, of exploration (April 10, 2006), Spirit's knowledge of its attitude relative to the sun has drifted. The rover uses an onboard computer to keep track of attitude changes, but error builds up in this measurement over time. On sol 855 (May 30, 2006), rover planners transmitted an attitude update of 1.97 degrees to correct for the drift. After the update, Spirit re-acquired images from the same location to allow the science team to accurately target future observations. |
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Jun 2 2006, 03:40 PM
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#4
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Senior Member Group: Members Posts: 4252 Joined: 17-January 05 Member No.: 152 |
From http://marsrovers.jpl.nasa.gov/mission/status.html: QUOTE SPIRIT UPDATE: Spirit Perfects Pointing Parameters, Collects Images Large and Small - sol 855-859, June 1, 2006: Since arriving at the rover's current location on the 807th sol, or Martian day, of exploration (April 10, 2006), Spirit's knowledge of its attitude relative to the sun has drifted. The rover uses an onboard computer to keep track of attitude changes, but error builds up in this measurement over time. Anyone understand what the nature of this drift is? I thought that normally this drift occured when the rover was driving, and hence accumulating errors while its orientation changes. In this case Spirit has been sitting still, and hasn't even settled according to the images. If it's orientation was known 50 sols ago it should be known as accurately tosol! |
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Jun 2 2006, 09:27 PM
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#5
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Member Group: Members Posts: 408 Joined: 3-August 05 Member No.: 453 |
Anyone understand what the nature of this drift is? A small bias in the noise levels of the gyros that would add up to a measurable change over many days? But that would be true when driving too, so what is so special now? The rover can still update its orientation based on sun angles, which could (would?) reset the attitude vectors I would think. Hm, a puzzle indeed... Airbag |
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Jun 3 2006, 08:15 AM
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#6
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Dublin Correspondent Group: Admin Posts: 1799 Joined: 28-March 05 From: Celbridge, Ireland Member No.: 220 |
The rover can still update its orientation based on sun angles, which could (would?) reset the attitude vectors I would think. The JPL update confirmed James' third alternative. The precision of the knowledge of the orientation of the rover was improved because they had many more sun pointing shots over time with which to refine the calculation. |
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