Terrapattern: a visual search tool for satellite imagery

Re:Terrapattern: a visual search tool for satellite imagery by dockd on Wednesday May 25, 2016 @05:04PM (#11773075)

In my experience in the USA, OpenStreetMap data that comes from TIGER (?) imports, like heliports, are close but wrong. Playgrounds and watertowers are usually accurate because someone added them by hand. Churches are mixed. Other items are confusing; a hospital is typically a single point, but they tend to be some of the largest buildings in small towns.

Any thoughts on how that affects your model?

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Re:Terrapattern: a visual search tool for satellite imagery by workergnome on Wednesday May 25, 2016 @05:22PM (#11773229)

We found the same—using OSM data that just had points was problematic, both because of accuracy and because it tended to often be the front door, not the centroid of the object.

I believe we limited our model generation to selecting places that had outlines, and computed the centroid of that outline. One of the benefits of our technique is that we didn't need to be comprehensive—we can throw out lots of places and still have enough to be useful for the model.

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Re:Terrapattern: a visual search tool for satellite imagery by maxerickson on Wednesday May 25, 2016 @05:10PM (#11773128)

Most of the messy point features in the US were imported from GNIS. TIGER is the primary source for the messy line features.

Sticking to features modeled as areas would generally avoid the spatial accuracy problems with GNIS.

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