MSL statistics, Odometry progress and other figures |
MSL statistics, Odometry progress and other figures |
Sep 6 2012, 05:37 PM
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#1
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Senior Member Group: Members Posts: 2492 Joined: 15-January 05 From: center Italy Member No.: 150 |
After first month on Mars, I think it's time to start a topic similar to MER one...
First odometry plot to start: -------------------- I always think before posting! - Marco -
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Apr 1 2014, 03:55 PM
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#2
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Senior Member Group: Members Posts: 2519 Joined: 13-September 05 Member No.: 497 |
Are you familiar with the coastline paradox? http://en.wikipedia.org/wiki/Coastline_paradox
There are so many error sources for odometry that it may not be physically meaningful to even discuss the "true" value. Even figuring out where the rover is at any given moment isn't free of ambiguity. I think you're doing a great job with the data you have. -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Apr 1 2014, 09:05 PM
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#3
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Senior Member Group: Members Posts: 1465 Joined: 9-February 04 From: Columbus OH USA Member No.: 13 |
Are you familiar with the coastline paradox? http://en.wikipedia.org/wiki/Coastline_paradox Yes! Benoit Mandelbrot's book had a chapter titled "How Long is the Coast of Britain" and the answer was: infinite, if you use a small enough ruler. It's more important for me to keep the map position more or less right, because when it deviates I definitely start getting emails. And now the rover is poised to travel beyond the bounds of my initial HiRISE map tiles. I'm working to add another set of tiles--hopefully it'll be done before the rover moves much further, now just a couple hundred meters from the edge. "There be dragons!" -------------------- |
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Apr 2 2014, 01:37 AM
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#4
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Senior Member Group: Members Posts: 4252 Joined: 17-January 05 Member No.: 152 |
the answer was: infinite, if you use a small enough ruler. I'm sure you're not suggesting it Phil, but of course we can be pretty sure the rover hasn't moved an infinite distance in a finite time, unless it has one of those experimental warp drives... But the point about resolution-dependence is well taken. Presumably if someone cared enough they could smooth the sampled path on some particular standard length scale and call that the path length. |
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Apr 2 2014, 09:11 AM
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#5
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Senior Member Group: Members Posts: 1465 Joined: 9-February 04 From: Columbus OH USA Member No.: 13 |
Presumably if someone cared enough they could smooth the sampled path on some particular standard length scale and call that the path length. The SPICE data appears to be smoothed piecewise linear--here's the first 200 seconds of a recent drive where the rover speed when moving was about 3 cm/sec: That's asking for the position every 10 msec, so evidently it doesn't get any more fractally than that. -------------------- |
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