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Kilometers on the ground
Glevesque
post Jul 21 2017, 10:48 AM
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Hello everyone !

I would like to know more about the mileage grid on the ground. I have difficulty finding precise data from various unofficial sources.

Here is my list:

______________________________________________________________________________
Bonjour a tous !

J'aimerais avoir des précisions sur la grille de kilométrage parcourus au sol. J'ai des difficulter a trouver des données bien précises à différentes sources non officiel.

Voici ma liste :
______________________________________________________________________________

1 km Sol 335, 17 juillet
2 km Sol 363, 14 août
3 km Sol 403, 24 sept
4 km Sol 431, 22 oct
5 km Sol 521, 23 janv
6 km Sol 568, 12 mars
7 km Sol 641, 26 mai
8 km Sol 668, 23 juin
9 km Sol 709, 4 août
10 km Sol 957, 16 avril
11 km Sol 1296
12 km Sol 1439
13 km
14 km Sol 1448
15 km
16 km Sol 1669


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pospa
post Jul 21 2017, 11:31 AM
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How about this one : http://www.curiositymsl.com/tracking/drivelog.html
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Glevesque
post Jul 21 2017, 11:55 AM
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Thank you, but I think the site does not take actual distances into account. It includes the general rolling without descriminating the landslides, the enclosures and others. I am referring to the actual mileage on the distance traveled on the Martian surface.

________________________________________________________________________________

Merci, mais je crois que le site ne tient pas compte des distances réel. Il inclut le roullement général sans descriminé les glissements, les enlisements et autres. Je fais référence au kilométrage réel sur les distance parcourus à la surface martienne.
________________________________________________________________________________


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RoverDriver
post Jul 21 2017, 11:00 PM
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The data on that web site appears to be matching the telemetry pretty well. If VO (visual odometer) is enabled the odometer does take into account slippage (if that's what you meant by landslide). VO is being used all the time nowadays but at the beginning of the mission it was left off or on auto *VO is automatically turned on by the rover under certain conditions). The odometer reports the overall distance traveled by the center of the vehicle which is obviously different from the odometer for each wheel (a turn-in-place counts as zero meters).

Paolo


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nogal
post Jul 23 2017, 11:18 PM
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Hello Glevesque,

Here is the data that I use for my MSL route map kmz (Google Earth) file. I hope it helps.

--------------------------------------
Salut Glevesque,

Voici les donnees que j'utilize dans mon fichier kmz de la route de MSL (Google Earth). Je souhaite qu'ils te seront utiles.
---------------------------------------
Fernando

Attached File  MSL_KML.txt ( 1.75K ) Number of downloads: 98


Km Sol Earth Date Information sources
1 335 16-07-2013 Analyst's Notebook entry for Sol 336
2 365 16-08-2013 Analyst's Notebook entry for Sol 365
3 406 27-09-2013 Analyst's Notebook entry for Sol 404 and 406
4 436 28-10-2013 Analyst's Notebook entry for Sol 438
5 540 11-02-2014 Analyst's Notebook entry for Sol 542
6 574 18-03-2014 Analyst's Notebook entry for Sol 575
7 655 10-06-2014 Analyst's Notebook entry for Sol 655
8 670 24-06-2014 Analyst's Notebook entry for Sol 670
9 735 31-08-2014 Analyst's Notebook entry for Sols 735-751
https://www.nasa.gov/press/2014/september/n...n/#.VBRvNWRdVVt
10 957 16-04-2015 Analyst's Notebook entry for this day gives total distance as 10231m,however
NASA/JPL press report below states the 10km mark was passed on this date
https://www.jpl.nasa.gov/news/news.php?feature=4556
11 1094 04-09-2015 Analyst's Notebook entry for Sol 1094
12 1248 09-02-2016 https://astrogeology.usgs.gov/news/astrogeo...rs-and-counting
However Analyst's Notebook entry for sol 1248 mentions "12305 Odometry"
13 1376 19-06-2016 https://mars.nasa.gov/multimedia/images/cur...on-for-sol-1376
14 1448 01-09-2016 https://mars.nasa.gov/multimedia/images/cur...on-for-sol-1448
15 1526 21-11-2016 https://mars.nasa.gov/multimedia/images/cur...on-for-sol-1526
16 1666 13-04-2017 https://mars.nasa.gov/multimedia/images/201...on-for-sol-1666
17 1754 13-07-2017 https://mars.nasa.gov/msl/mission/mars-rove...-behind-the-sun
...................................................................
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Gerald
post Jul 24 2017, 04:00 PM
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QUOTE (pospa @ Jul 21 2017, 01:31 PM) *

Note the glitch on Sol 967 of unresolved cause, which suggests a drive of 346.56 m. The map is displaced since then.
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PaulH51
post Jul 24 2017, 08:49 PM
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QUOTE (Gerald @ Jul 25 2017, 12:00 AM) *
Note the glitch on Sol 967 of unresolved cause, which suggests a drive of 346.56 m. The map is displaced since then.

Joe used to periodically (manually) adjust the drive distances / path, to bring his map in line with the actual path. It appears to been quite some time since he carried out maintenance on the page as other functions such as 'Map It' that relied on his mapping function can no longer be used. I still use his page for other activities such as the camera pointing info and image sorting.


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Glevesque
post Jul 25 2017, 12:24 PM
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thank you very much nogal !


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elakdawalla
post Jul 25 2017, 05:04 PM
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There is also a lot of information available in the PLACES database:
https://pds-imaging.jpl.nasa.gov/data/msl/MSLPLC_1XXX/

Unfortunately, while it includes positions, it does not include drive odometry. You can get some of that from Vasavada et al. papers:
http://onlinelibrary.wiley.com/doi/10.1002...004622/abstract


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nogal
post Jul 30 2017, 05:05 PM
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One more thing I'd like to add: The PLACES database - on which most of Curiosity's route map for my GE file is based - includes for each location entry the (x,y,z) distances to the landing location.
Thus it would seem that computing the 3D distance between two successive locations would give that segment's length, and that adding all of the segments would allow computing the total traveled distance.
Here is a table of the sols in which each km was crossed (up to km 15, the latest covered by PDS release 14) and a comparison with the previously posted table. As can be seen, there are some differences, sometimes large, and I don't know why. I'd be indebted if anyone can provide an explanation, by posting it here or by PM. Cheers

... Sol..... Sol
Sol Computed External
1 335 335
2 369 365
3 406 406
4 437 436
5 546 540
6 589 574
7 657 655
8 672 670
9 743 735
10 956 957
11 1080 1094
12 1196 1248
13 1357 1376
14 1438 1448
15 1514 1526
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RoverDriver
post Jul 30 2017, 06:35 PM
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QUOTE (nogal @ Jul 30 2017, 10:05 AM) *
One more thing I'd like to add: The PLACES database - on which most of Curiosity's route map for my GE file is based - includes for each location entry the (x,y,z) distances to the landing location.
Thus it would seem that computing the 3D distance between two successive locations would give that segment's length, and that adding all of the segments would allow computing the total traveled distance.
....


It depends on what you mean by traveled distance. Places only reports the coordinates of each stopping location and connecting each stop with a straight line would not take into account the swerving and turns we typically do while driving the rovers. This is especially true in rough terrain. The odometer that JPL typically reports does take that into account.

Paolo


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Glevesque
post Jul 31 2017, 02:03 PM
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QUOTE (Gerald @ Jul 24 2017, 12:00 PM) *
Note the glitch on Sol 967 of unresolved cause, which suggests a drive of 346.56 m. The map is displaced since then.


J'aimerais également comprendre d'ou vient la différence de calcule sur la distance journalière parcourus entre ses deux sites :

Exemple pour le Sol 406 :

72,94 mètres pour http://www.curiositymsl.com/tracking/drivelog.html

66,8 mètres pour http://www.midnightplanets.com/web/MSL/sol/00406.html (cumulatif)
_______________________________________________________________________


I would also like to understand where the difference in the daily distance traveled between its two sites is calculated:

Example for Sol 406:

72,94 mètres for http://www.curiositymsl.com/tracking/drivelog.html

66,8 mètres for http://www.midnightplanets.com/web/MSL/sol/00406.html (cumulatif)




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nogal
post Jul 31 2017, 05:22 PM
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QUOTE (RoverDriver @ Jul 30 2017, 07:35 PM) *
It depends on what you mean by traveled distance.

Many thanks for your reply, Paolo. Appreciated.
Wouldn't including the twists and turns - which, to me, seems the correct thing to do - make the odometry grow faster and, thus, crossing the km mark earlier? This seems to be the case up to km 10 (comparing the two columns) but not afterwards.
As a curiosity: the average segment size is 0.9024 m with a standard deviation of 0.6396
I'm sticking to the JPL announcements smile.gif
Fernando
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RoverDriver
post Jul 31 2017, 06:19 PM
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QUOTE (nogal @ Jul 31 2017, 10:22 AM) *
Many thanks for your reply, Paolo. Appreciated.
Wouldn't including the twists and turns - which, to me, seems the correct thing to do - make the odometry grow faster and, thus, crossing the km mark earlier?
....
As a curiosity: the average segment size is 0.9024 m with a standard deviation of 0.6396
I'm sticking to the JPL announcements smile.gif
Fernando


Yes, it should but in cases where we had a very high value of slip that might have not been accounted for by the on-board software, or because of accumulated errors in position estimate, the rover might think it has moved more than it actually did so periodically Tim Parker (our resident Phil Stooke) re-localizes the vehicle position, and that's what it is poked in PLACES. While MSL has a better definition of rover odometry than MER it is still not uniquely defined. As the saying goes "a man with a watch knows what time it is, a man that has two is never sure!"

Regarding the average segment length, I actually never measured it. This also would require a definition of what "straight line segment" actually means. I typically use the Pavlidis algorithm to define a straight line segment and set the tolerance to 10% (if the width of a set of points is within 10% of the length of the path, I call is a straight segment). If I have some spare time, I will run some numbers.

Paolo


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Phil Stooke
post Jul 31 2017, 11:56 PM
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"our resident Phil Stooke"

Inside every Phil Stooke is a Tim Parker trying to get out (I have TARDIS-like qualities)

I am studiously avoiding this discussion (oops, until now) because it's so difficult to sort out exactly what these distances mean. I don't think we can definitively answer the simple-sounding question 'how far has the rover moved', not to everybody's satisfaction. Any distance flags I put on my maps are only approximations.

Phil


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