Opportunity Route Map Options

[Tesheiner]

Sol 2348.

 Route_Map_Sol2348.kml ( 57.88K ) Number of downloads: 119

[ElkGroveDan]

Chit chat posts moved to the drive discussion topic: From Cambridge Bay to the "parking lot"

Let's try to remember to keep this topic for route map updates.

[Tesheiner]

Sol 2349.

 Route_Map_Sol2349.kml ( 58.06K ) Number of downloads: 137

[Vultur]

Is each grid square 100 x 100 meters?

[Tesheiner]

Yup.

Here's today's map update corresponding to sol 2353.

 Route_Map_Sol2353.kml ( 58.24K ) Number of downloads: 153

[Tesheiner]

Here's the latest map update, with another km mark just behind: 23km. It's a "draft" version since it still has to be adjusted with the help of the navcam pics.
Sol 2355.


 Route_Map_Sol2356.kml ( 58.8K ) Number of downloads: 128


Edit: Updated, because it was off by around 4 meters. It's not a big issue on a single move but this error when accumulated drive after drive may be significant.

This post has been edited by Tesheiner: Sep 10 2010, 07:59 AM

[climber]

I played around with Google Earth as well as Eduardo map from post #2833 and try to find when and where we'll cross the 13kms in strait line from Eagle. You'll find here what I've got.



Anyway there's a problem. Using Google rule, it's easy to calculate distance and as you'll see here, the "probable" 13 km from Eagle circle is close from 2 remarkable lines on Eduardo's grid: the vertical 2 km East and the horizontal 13 km South. Unless Maths are different on Mars, Pythagoras is not going to be happy with that! So, either Google rule is corupted, or Eduardo's grid is wrong or, more probably, I AM wrong. Anyway, I thought I'd better post this either for Eduardo to double check is grid or to know from you if we can trust Google rule. Thanks

Note: the probable circle has been set by assuming the route will continue at the same heading (which is close to the "blue" projected official route) as the one from Cambridge to sol 2356 and not shown here since we were not there yet on post #2833 . Note that the distance from Cambridge to this point is (says Google rule) 1 km (1003m to be precise).

[Tesheiner]

What I can say about the grid is that it is based on the fact (?) that the background picture has a resolution of 1m/pix. That picture was taken by HiRISE and is labelled PSP_009141_1780. Note that the original picture taken by the camera has a different resolution (26.9cm/pix), but the "map projected" one has 25cm/pix and my route map uses the latter one at 1/4th size.

An "error" in the map projection process? I don't think so. Perhaps it is related to the fact that the images used on GE have a significant "emission angle" so they are slightly distorted.

Perhaps Phil Stooke or Tim Parker could provide some light to this topic.

[Floyd]

Climber--how great is the discrepancy? Putting a flat grid on a sphere leads to small discrepancies on a small scale and major discrepancies on global scales.
You are correct Tesheiner---"Perhaps Phil Stooke or Tim Parker could provide some light to this topic".

[climber]

Climber--how great is the discrepancy?

I'd say Pythagorias is easily your friend in this case
Hypothenuse² = horizontal² + vertical² = 169+4=√173
13153m instead of 13000m

[Phil Stooke]

Don't forget that the map-projected images take into account only an idealized smooth surface - these are not orthophotos corrected for relief distortion. Meridiani Planum is smooth but not perfectly flat, and a discrepancy of a few hundred meters after 13000 m is probably quite reasonable. If you only look at one map-projected image it's easy to think it must have perfect geometry, but try overlaying one image on top of another and you'll find discrepancies at this level.

Phil

[climber]

I should have said Philthagoras is your friend...

[Tesheiner]

Sol 2358.

 Route_Map_Sol2358.kml ( 59.02K ) Number of downloads: 156

[Tesheiner]

Here's a (late) update related to sol 2361. I was off the town with no way to "work" on due time.

 Route_Map_Sol2361.kml ( 59.2K ) Number of downloads: 83

[Tesheiner]

Sol 2363.

 Route_Map_Sol2363.kml ( 59.57K ) Number of downloads: 144