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>Phones GPS give a 2 meters accuracy Well I already pointed out that if you're within a couple meters of the boundary, you won't have good confidence because o
by shiroiushi 2y ago
>Phones GPS give a 2 meters accuracy
Well I already pointed out that if you're within a couple meters of the boundary, you won't have good confidence because of this fact.
>and a park boundary is a well defined hard line polygon.
Is it? I'm no expert on parks, but surely some of them have borders along rivers. Many US states have such borders.
>Being close to the border changes nothing, I can just add a buffer outwards the park polygon to account for that.
That doesn't account for the 2m accuracy. What if I'm standing exactly 1m from the boundary when I take the photo? You have no idea if I'm really in the park or not from the GPS data.
I also have serious doubts about your 2m accuracy claim, based on personal experience. Maybe if you're standing in a wide-open desert with nothing around you, but anywhere else, the accuracy isn't that great, especially around buildings. GPS accuracy is terrible in cities.
- ddoeth 2y ago> Is it? I'm no expert on parks, but surely some of them have borders along rivers. Many US states have such borders. Depending on the country, but Australia has some [1]. I still think that there is a set of polygons that can be used to describe this border. Not to argue against your point (I rarely get less than 4m of accuracy), but luckily > but anywhere else, the accuracy isn't that great, especially around buildings. GPS accuracy is terrible in cities. cities are (almost?) never in national parks. [1]: https://www.nationalparks.nsw.gov.au/-/media/npws/maps/pdfs/parks/border-ranges-national-park/border-ranges-national-park-map.pdf https://www.nationalparks.nsw.gov.au/-/media/npws/maps/pdfs/...
- shiroiushi 2y ago>cities are (almost?) never in national parks. Sometimes they are. See Washington, DC. Anyway, the requirement is for determining if a photo was taken in a park or not. The resolution wasn't stated, however: just how accurate do we need to be? If I'm in a canoe in a river that borders a park, but the river isn't part of the park, but the shoreline a few meters away is, our algorithm might claim I'm in the park, when I'm really not. The requirement wasn't "somewhere near a park", but "in a park". Rivers change their courses over time, so some polygons aren't going to accurately describe this border.
- ric2b 2y agoLet's be real, GPS is much more accurate than whatever boundary for the national park that someone might come up with, where the park starts is really ambiguos unless there's a physical man made divisor like a fence.