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Reprojecting the Perseverance landing footage onto satellite imagery

matthewearl.github.io

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Re: Reprojecting the Perseverance landing footage onto satellite imagery

#8
An interesting side point is that the graph optimization approach used here is somewhat similar to modern graph-based visual SLAM

The graph in the article can be seen as a factor graph. VSLAM systems usually have a (kind of bipartite) factor graph with vertices/variables that are either keyframes or ‘good’ features, with edges/factors between features and the frames that see them and between adjacent frames; each of these edges are the factors in the graph. This structure results in very large but sparse graphs, and there are factor graph optimization libraries that take advantage of this sparsity (e.g. g2o or GTSAM.) These libraries also use specialized optimization techniques for some of the nonlinear manifolds (e.g. SO(3)) that arise in SLAM problems.

Re: Reprojecting the Perseverance landing footage onto satellite imagery

#9
post #5

I've done this kind of stuff through a point and click UI in GIS software. It's really cool seeing a lot of the underlying math and concepts laid out like this.

I'm curious - what did you do, in what software, and how?

ESRI software has had this raster function for quite a while, at least 20 years. Usually 2 or 3 points would suffice. Using hundreds of points was unnecessary.
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