Yutu Route Map |
Yutu Route Map |
Dec 15 2013, 04:30 PM
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#1
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Solar System Cartographer Group: Members Posts: 10226 Joined: 5-April 05 From: Canada Member No.: 227 |
First route map! I will keep it going, mostly on LROC images, as I need it for a future project. I am still working on an accurate scale.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PDF: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Feb 26 2014, 04:19 PM
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#2
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Senior Member Group: Members Posts: 4256 Joined: 17-January 05 Member No.: 152 |
Yes, that's what I meant - if you knew the relative separation of the L and R rover cameras, then you can find the distance to the lander. I know information is sparse with this mission. But it may be possible to measure the L/R separation from a lander photo of the rover at known distance, or simply by comparing the L/R separation to the total width of the rover, if that's known reasonably well.
Knowing the L/R separation of the rover cameras (orthogonal to their optical axes), then it's a simple matter of trig to convert the measured parallax between the lander and the distant horizon (effectively at infinity) to the lander distance. (Maybe this is what you meant Paolo - without an absolute direction reference, we could not do this, since the L/R optical axes may not be parallel. But we do have such a reference, given by features on the distant horizon in the images.) |
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Feb 26 2014, 05:20 PM
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#3
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Founder Group: Chairman Posts: 14434 Joined: 8-February 04 Member No.: 1 |
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Feb 26 2014, 06:46 PM
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#4
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Senior Member Group: Members Posts: 4256 Joined: 17-January 05 Member No.: 152 |
AND the degree of toe in, if any. That can be measured in pixels by looking at the shift in features on the distant horizon (effectively at infinity).The basic problem is that we need to know the pixel scale of the camera to convert pixels to an angle. Equivalently, as Paolo says, we need an object of known size and distance to give us a known angle. I'm used to MER/MSL, where we have that info easily available. But I'm guessing that's not the case with this mission. In principle, we could estimate the pixel scale since we have 360 degree pans. So if we can match distant features between the 360 and these new L/R images, we could estimate angles. Or, we could look at rover pancam images from the first lunar days and estimate the pixel scale from the (presumably) known size of the lander and distance from Phil's map. Then you have to assume/guess that those images are full frame rather than cropped. Either way, a lot of work. |
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